EduDivision-DATACOM NETWORKING

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EduDivision-DATACOM NETWORKING

  1. 1. CommServ – Education Division Datacom NetworkingIntroduction-1 Data Communication Transport
  2. 2. CommServ – Education Division Datacom NetworkingIntroduction-2 Introduction • Name, Company and Location • Job Title and Responsibilities • Related Work Experience • Course Expectations
  3. 3. CommServ – Education Division Datacom NetworkingIntroduction-3 Course Prerequisites • There are no prerequisites for this course.
  4. 4. CommServ – Education Division Datacom NetworkingIntroduction-4 Course Materials • Course Manual • Evaluation Form • Reference Materials
  5. 5. CommServ – Education Division Datacom NetworkingIntroduction-5 Course Objectives • To gain a solid understanding of modern data communications technologies and concepts • Technologies covered: – TCP/IP, Ethernet, ATM, Frame Relay, X.25, PPP, Modems, ISDN, xDSL, SDH/SONET, Packet-over-SONET, MPLS
  6. 6. CommServ – Education Division Datacom NetworkingIntroduction-6 Course Schedule •Day 1: PRE-TEST, Standards, Physical Media, Datacom Concepts & Traffic Cases •Day 2: Ethernet Concepts, Ethernet Frame Types & Devices Fast & Gigabit Ethernet •Day 3: WAN Concepts, ATM and Frame Relay •Day 4: WAN Concepts, X.25, Point-to-Point Protocol, Modems, ISDN, xDSL, PDH/SDH/SONET, Packet-Over-SONET, MPLS •Day 5: Internet Architecture & Applications, Transport Layer, Protocols, Internet Protocol & IP Addressing, Internet Routing & Dynamic Routing POST TEST
  7. 7. CommServ – Education Division Datacom NetworkingIntroduction-7 Modern Datacom Networking
  8. 8. CommServ – Education Division Datacom NetworkingStandard-8 Datacom Networking 2. Standardization and the OSI Model Chapter Objectives –Identify the standards bodies associated with data communications –Describe in detail the OSI reference model
  9. 9. CommServ – Education Division Datacom NetworkingStandard-9 Standard Bodies Frame Relay Forum IEEE ITU ISO ANSI IETF ATM Forum ETSI
  10. 10. CommServ – Education Division Datacom NetworkingStandard-10 International Telecommunications Union (ITU) ITU-R Study Group Study Group ITU-T ITU-D ITU
  11. 11. CommServ – Education Division Datacom NetworkingStandard-11 ITU-T Recommendations FunctionSeries Public data communication networkX- Digital communication over the telephone networkV- Telephone switching and signalling networksQ- ISDNI- International telephone connections and circuitsG- Telephone network and ISDNE-
  12. 12. CommServ – Education Division Datacom NetworkingStandard-12 Standards Organizations • International Telecommunications Union – www.itu.int • International Standards Organisation – www.iso.ch • American National Standards Institute – www.ansi.org • European Telecommunications Standards Institute – www.etsi.org • Electronic Industries Alliance – www.eia.org • Internet Engineering Task Force – www.ietf.org
  13. 13. CommServ – Education Division Datacom NetworkingStandard-13 Standards Organizations • Frame Relay Forum – www.frforum.com • Institute of Electrical and Electronics Engineers – www.ieee.org • International Multimedia Teleconferencing Consortium – www.imtc.org
  14. 14. CommServ – Education Division Datacom NetworkingStandard-14 OSI Reference Model • The Open System Interconnection (OSI) Reference Model is a concept that describes how data communications should take place • It divides the process into seven groups, called layers • Protocol standards developed by the ISO and other standards bodies are fitted into these layers • The OSI model is not a single definition of how data communications actually takes place in the real world, Numerous protocols may exist at each layer • The OSI model is old, but it’s important because modern functionality is defined using the language of the OSI model, for example “layer 2 forwarding”
  15. 15. CommServ – Education Division Datacom NetworkingStandard-15 OSI Reference Model Layers Transmits and receives on the network mediumPhysical1 Transfers units of information to the other end of the physical link Data Link2 Switches and routes information to the appropriate network device Network3 Provides end-to-end data integrity and reliable delivery of data Transport4 Co-ordinates interaction between end-to-end application processes Session5 Provides code conversion and data reformatting Presentation6 Interfaces directly with application programs running on the devices Application7
  16. 16. CommServ – Education Division Datacom NetworkingStandard-16 The Physical Layer TDM / FDM / WDMMultiplexing Baseband Broadband Bandwidth Usage Asynchronous Synchronous Bit Synchronisation Current StateSignalling Bus, Ring, CellularPhysical Topology P-2-P , P-2-MPConnection Types Physical MethodsFunctionLayer
  17. 17. CommServ – Education Division Datacom NetworkingStandard-17 The Datalink Layer DLC Physical device Addressing Contention Token passing Media access services Bus Ring Logical topology MAC Flow control Error control Connection services Asynchronous Synchronous Transmission Synchronisation LLC MethodsFunctionSub layer
  18. 18. CommServ – Education Division Datacom NetworkingStandard-18 Network Layer Static Dynamic Route Selection Distance Vector Link State Route Discovery Packet SwitchingSwitching Logical Network Services Addressing Network MethodFunctionLayer
  19. 19. CommServ – Education Division Datacom NetworkingStandard-19 Routing 6 5 4 3 2 3 3 2 1 1 1 3 2 3 2 4 5 6 1 4 5 6
  20. 20. CommServ – Education Division Datacom NetworkingStandard-20 Transport Layer Service requester initiated Address/Name Resolution Segment sequencing Error control End-2-End flow control Connection services Segmentation and Reassembly (SAR) Segment development Connection identifier Transaction identifier Addressing Methods Transport MethodFunctionLayer
  21. 21. CommServ – Education Division Datacom NetworkingStandard-21 Session Layer • Session layer facilitates and controls communication sessions between service providers and service requesters • The session layer has functions to establish maintain, synchronise and manage communication sessions • Often, it also helps the upper layers identify and connect to the services available on the network. • The two main session layer tasks are: • Dialogue control • Session administration • This includes the control and management of multiple bidirectional messages so that the application can be notified if only some of a series of messages are completed. • For example, an Automated Teller Machine transaction in which you get cash out of your checking account should not debit your account and fail before handing you the cash, and then record the transaction even though you did not receive money. • RPC, SQL, NFS, NetBios names, AppleTalk ASP, DECnet SCP
  22. 22. CommServ – Education Division Datacom NetworkingStandard-22 Presentation Layer • This layer’s main purpose is defining data formats, such as ASCII text, EBCDIC text, binary, BCD, and JPEG. • Encryption is also defined by OSI as a presentation layer service. • For example, FTP allows you to choose binary or ASCII transfer. If binary, the sender and receiver do not modify the contents of the file. If ASCII is chosen, the sender translates the text from the sender’s character set to a standard ASCII and sends the data. The receiver translates back from the standard ASCII to the character set used on the receiving computer. • Example: TIFF, GIF, JPEG, PICT, ASCII, EBCDIC, encryption, MPEG, MIDI, HTML
  23. 23. CommServ – Education Division Datacom NetworkingStandard-23 Presentation Layer The presentation layer’s main functions are: • Translation • Code conventions • Bit/Byte order • File syntax • Encryption / Decryption
  24. 24. CommServ – Education Division Datacom NetworkingStandard-24 Application Layer • Provides interface to end user process and applications • Takes care of all the requests made by the running applications • An application that communicates with other computers is implementing OSI application layer concepts. The application layer refers to communications services to applications. For example, a word processor that lacks communications capabilities would not implement code for communications, and word processor programmers would not be concerned about OSI Layer 7. However, if an option for transferring a file were added, then the word processor would need to implement OSI Layer 7 (or the equivalent layer in another protocol specification). • Examples: FTP, WWW browsers, Telnet, NFS, SMTP gateways (Eudora, CC:mail), SNMP, X.400 mail, FTAM
  25. 25. CommServ – Education Division Datacom NetworkingStandard-25 Data Transmission Bits S-Data unit T-Data unit Packet Frame Bits P-Data unit A-Data unitDataA Data Physical Data Link Network Transport Session Presentation Application DataAP DataAPS S DataAPT T S DataAPN N T S DataAPD D 101101111000101011010010101010 ProtocolStack Data unit
  26. 26. CommServ – Education Division Datacom NetworkingStandard-26 Example: HTTP Web Browser Physical Data Link Network Transport Session Presentation Application Ethernet IP TCP HTTP Web Server Ethernet IP TCP HTTP
  27. 27. CommServ – Education Division Datacom NetworkingStandard-27 OSI and Network Devices Physical Data Link Network Transport Session Presentation Application Physical Data Link Network Transport Session Presentation Application Repeater Bridge Router Hub Switch Router User Application User Application
  28. 28. CommServ – Education Division Datacom NetworkingStandard-28 OSI and Network Devices
  29. 29. CommServ – Education Division Datacom NetworkingStandard-29 OSI Layers: Network Interaction Physical Data Link Network Transport Session Presentation Application Physical Data Link Network Transport Session Presentation Application User Application User Application
  30. 30. CommServ – Education Division Datacom NetworkingStandard-30 OSI Model Summary Concerned with transmission of unstructured bit stream over physical medium; deals with the mechanical, electrical, functional and procedural characteristics to access the physical medium. 1) Physical Provides for the reliable transfer of information across the physical link. Establishes a physical link, sends blocks of data (frames) in the proper format, along with the necessary synchronization, error control, and flow control. 2) Data Link Provides upper-layers with independence from the data transmission and switching technology used to connect systems. Concerned with routing packets, congestion control, fragmentation, and reassembly. 3) Network Provides reliable, transparent transfer of data between end points. Provides end-to-end error recovery and flow control. 4) Transport Provides the control structure for communication between applications. Establishes, manages and terminates connections (sessions) between applications. 5) Session Provides data representation (Syntax) independence to the application process. 6) Presentation Access to the OSI environment for user applications and processes.7) Application
  31. 31. CommServ – Education Division Datacom NetworkingPhysical Media Datacom Networking 3. Physical Media Chapter Objectives –Describe the characteristics of coaxial cable, UTP, STP and optical fiber –Describe the terms DCE and DTE –Describe the characteristics of RS232, RS422, V.35, V.36 and X.21
  32. 32. CommServ – Education Division Datacom NetworkingPhysical Media Physical Media • Co-axial • Twisted Pair – Unshielded – Shielded • Optical Fiber – Single Mode – Multimode
  33. 33. CommServ – Education Division Datacom NetworkingPhysical Media Typical Coaxial Cable BNC Connectors
  34. 34. CommServ – Education Division Datacom NetworkingPhysical Media BNC T-Connector
  35. 35. CommServ – Education Division Datacom NetworkingPhysical Media Characteristics of Coax • Medium cable costs • Simple to install • Moderate installation costs • Moderate EMI • High bandwidth • Often used as backbone cable
  36. 36. CommServ – Education Division Datacom NetworkingPhysical Media Unshielded Twisted Pair
  37. 37. CommServ – Education Division Datacom NetworkingPhysical Media Characteristics of UTP • Lowest cost • Very simple to install • Low installation costs • Highest electromagnetic interference (EMI) • Lowest in bandwidth • Used in more than 99% of LANs
  38. 38. CommServ – Education Division Datacom NetworkingPhysical Media Categories of UTP for Networks • Category 3 (Cat 3) – Bandwidth 16 Mhz – Data transmission function – 11.5 dB attenuation – 100 ohms Impedience – Used with 10baseT (10Mbps), IBM token ring (4Mbps), ARCnet, 100VG- AnyLAN (100 Mbps) • Category 4 (Cat 4) – 20 MHz Bandwidth – Data transmission function – 7.5 dB Attenuation – 100 ohms Impedance – Used with 10baseT (10Mbps), IBM Token ring, ARCnet, 100VG-AnyLan (100 Mbps)
  39. 39. CommServ – Education Division Datacom NetworkingPhysical Media Categories of UTP for Networks (2) • Category 5 (Cat 5) – 100 MHz Bandwidth – Used for high-speed data transmission – 24.0 dB Attenuation – 100 ohms Impedance – Used with 10BaseT (10 Mbps), IBM Token ring, Fast Ethernet, (100 Mbps), Gigabit Ethernet (1000 Mbps), ATM (155 Mbps) • Category 5 Enhanced (Cat 5E) – 100 MHz Bandwidth – Transmits high-speed data – 24.0 dB Attenuation – 100 ohms Impedance – Used with 10BaseT (10 Mbps), IBM Token Ring, Fast Ethernet (100 Mbps), Gigabit Ethernet (1000 Mbps), ATM (155 Mbps)
  40. 40. CommServ – Education Division Datacom NetworkingPhysical Media Categories of UTP for Networks (3) • Category 6 (Cat 6) – 250 MHz Bandwidth – Transmits high-speed data – 19.8 dB Attenuation – 100 ohms Impedance – Used with 10BaseT (10 Mbps), IBM Token Ring, Fast Ethernet (100 Mbps), Gigabit Ethernet (1000 Mbps), ATM (155 Mbps) • Category 6 Enhanced (Cat 6E) – 250 MHz Bandwidth – Transmits high-speed data – 19.8 dB Attenuation – 100 ohms Impedance – Used with 10BaseT (10 Mbps), IBM Token Ring, Fast Ethernet (100 Mbps), Gigabit Ethernet (1000 Mbps), ATM (155 Mbps) • Category 7 (Cat 7-NOT YET APPROVED) – 600 MHz Bandwidth – Transmits high-speed data
  41. 41. CommServ – Education Division Datacom NetworkingPhysical Media Shielded Twisted Pair
  42. 42. CommServ – Education Division Datacom NetworkingPhysical Media
  43. 43. CommServ – Education Division Datacom NetworkingPhysical Media Characteristics of STP • Medium cable costs expense • Simple to moderate installation difficulty • Moderate installation costs • Moderately low EMI • Moderate band width • Usually found in older networks
  44. 44. CommServ – Education Division Datacom NetworkingPhysical Media Optical Fiber
  45. 45. CommServ – Education Division Datacom NetworkingPhysical Media Single Mode and Multimode Fiber • Single Mode Fiber – Small core diameter which only allows one mode (ray) of light to propagate through the fiber – Used for applications with long transmission distances (carrier core networks) • Multimode Fiber – Larger core diameter which allows many modes of light to propagate through the fiber – Larger core diameter facilitates use of cheaper components – Used primarily for applications with short (<2Km) transmission distances (campus backbones)
  46. 46. CommServ – Education Division Datacom NetworkingPhysical Media Characteristics of Fiber • Highest cable costs • Difficult to install • Highest installation costs • No EMI • Very high bandwidth • Uses light rather than electrical signals
  47. 47. CommServ – Education Division Datacom NetworkingPhysical Media DCE Vs DTE DCE DCE DTE DTE V.24, V.28, Client/Calling Server/Called/ Modem Answer Modem PSTN V.24, V.28, V.90/V.34/V.32 V.42/V.42bis
  48. 48. CommServ – Education Division Datacom NetworkingPhysical Media Physical Layer Standards RS-232C (EIA) / V.24 (ITU) generator receiver A Bcommon ground pin 7 RS232C (V.24, V.28)
  49. 49. CommServ – Education Division Datacom NetworkingPhysical Media Physical Layer Standards (contd) generator receiver A B RS422 (V.11, X.27) R RS-422 (EIA) / V.11 (ITU)
  50. 50. CommServ – Education Division Datacom NetworkingPhysical Media Data Rate vs. Cable Length 100 1k 10k cable length (feet) 50 10 Data Rate - bps 100 1k 10k 100k 1M 10M RS-232 4k RS-422
  51. 51. CommServ – Education Division Datacom NetworkingPhysical Media V.24/V.28, RS232c Interface ISO 2110 Connector 1 13 14 25
  52. 52. CommServ – Education Division Datacom NetworkingPhysical Media 9 - 25 pin D Cable PC 9 Pin Modem 25 Pin Function in the PC 3 2 TxD Transit Data 2 3 RxD Receive Data 7 4 RTS Request to Send 8 5 CTS Clear to Send 6 6 DSR Data Set Ready 5 7 SG Signal Ground 1 8 DCD Carrier Detect 4 20 DTR Data Terminal Ready 9 22 RI Ring Indicator
  53. 53. CommServ – Education Division Datacom NetworkingPhysical Media V.24 Interface Circuits Pin V.24 RS232c DTE DCE EIA Description 1 101 AA FG Protective Ground 2 103 BA X TxD Transmit Data 3 104 BB X RxD Receive Data 4 105 CA X RTS Request to Send 5 106 CB X CTS Clear to Send 6 107 CC X DSR Data Set Ready 7 102 AB SG Common Return / Signal Ground 8 109 CF X DCD Data Carrier Detect 15 114 DB X TC Transmit Timing Clock 17 115 DD X RC Receive Timing Clock 20 108 CD X DTR Data Terminal Ready 22 125 CE X RI Ring Indicator 24 113 DA X TC External Transmit Timing Clock Other pins not shown used used in some modem circuits only.
  54. 54. CommServ – Education Division Datacom NetworkingPhysical Media Null Modem Cable 25 pin to 25 pin D Pin Signal 7 Signal Ground 2 Transmit 3 Receive 4 RTS 5 CTS 20 DTR 6 DSR 8 DCD Signal Pin Signal Ground 7 Transmit 2 Receive 3 RTS 4 CTS 5 DTR 20 DSR 6 DCD 8
  55. 55. CommServ – Education Division Datacom NetworkingPhysical Media Pin Signal 5 Signal Ground 3 Transmit 2 Receive 7 RTS 8 CTS 4 DTR 6 DSR 1 DCD Signal Pin Signal Ground 5 Transmit 3 Receive 2 RTS 7 CTS 8 DTR 4 DSR 6 DCD 1 Null Modem Cable 9 pin to 9 pin D
  56. 56. CommServ – Education Division Datacom NetworkingPhysical Media V.35 Interface KK EE AA W S M H C MM HHCC Y U P K E A LL FF BB X T N J D DDJJNN Z V R L F B ISO 2593 Connector
  57. 57. CommServ – Education Division Datacom NetworkingPhysical Media V.35 Interface (contd) ITU-T No. Circuit Pin Number Source Source Designation DTE DCE 102 GND B Signal Ground 103 TXD P , S X Transmit Data a,b 104 RXD R , T X Receive Data a,b 105 RTS C X Request to Send 106 CTS D X Clear to Send 107 DSR E X Data Set Ready 108.1 DTR H X Data Terminal Ready 109 DCD F X Data Carrier Detect 113 TCX U , W X Transmit Signal timing a,b from DTE 114 TXC Y , AA X Transmit Signal timing a,b to DTE 115 RXC V , X X Receive Signal timing a,b to DTE 140 RL N X Remote Digital Loop 141 LL L X Local Loop 142 TST NN X Test Indicator
  58. 58. CommServ – Education Division Datacom NetworkingPhysical Media V.36 Interface 1 19 3720 ISO 4902 Connector
  59. 59. CommServ – Education Division Datacom NetworkingPhysical Media X.21 Interface 1 8 9 15 ISO 4903 Connector ITU-T. Pin Number Source Source Designation circuit DTE DCE G 8 Signal Ground T 2, 9 X Transmit Data a,b R 4, 11 X Receive Data a,b C 3, 10 X Control a, b I 5, 12 X Indication a, b S 6, 13 X Signal element timing a, b
  60. 60. CommServ – Education Division Datacom NetworkingPhysical Media RJ 45 Ethernet Pin Name Description 568A 568B 1 TD + Transmit Data + White/Green White/Orange 2 TD - Transmit Data - Green Orange 3 RD + Receive Data + White/Orange White/Green 4 n/c Not connected Blue Blue 5 n/c Not connected White/Blue White/Blue 6 RD - Receive Data - Orange Green 7 n/c Not connected White/Brown White/Brown 8 n/c Not connected Brown Brown Note 1 Cable has four pairs. White/Green and Green are a pair etc. Note 2 TD & RD are swapped on Hub's.
  61. 61. CommServ – Education Division Datacom NetworkingPhysical Media Pin Function Required TE NT 1 Power source 3 + Power sink + No 2 Power source 3 - Power sink - No 3 Transmit + 4 Receive + 5 Receive - 6 Transmit - 7 Power sink 2 - Power source 3 - No 8 Power sink 2 + Power source 3 + No Note: Power source 2 and 3 are not mandatory and may only be available from some NT or TE devices. RJ 45 ISDN BRI s/t Interface
  62. 62. CommServ – Education Division Datacom NetworkingPhysical Media RJ 48c Pin Description 1 Receive Ring 2 Receive Tip 3 Not connected 4 Transmit Ring 5 Transmit Tip 6 Not connected 7 ground for transmit screen 8 ground for receive screen E1 / T1 Balanced/Unbalanced
  63. 63. CommServ – Education Division Datacom NetworkingPhysical Media SC Connectors
  64. 64. CommServ – Education Division Datacom NetworkingPhysical Media ST Connectors
  65. 65. CommServ – Education Division Datacom NetworkingPhysical Media LC FC MTRJ Mini-Gbic plus LC, MRTJ and FC Connector Mini-Gbic
  66. 66. CommServ – Education Division Datacom NetworkingFundamental - Datacom Networking 4. Datacom Fundamental Chapter Objectives –Define LANs and WANs –Identify multiplexing, transmission, and error control methods –Describe common network topologies
  67. 67. CommServ – Education Division Datacom NetworkingFundamental - Network Definition - LAN / WAN Local Area Networks (LANs) Router A Router B Wide Area Network (WAN) Token Ring
  68. 68. CommServ – Education Division Datacom NetworkingFundamental - Bandwidth Usage • Baseband all the available bandwidth is used to derive a single transmission path • Broadband the total available bandwidth of the cable is divided into a number of lower bit rate channels, which can transmit many simultaneous signals
  69. 69. CommServ – Education Division Datacom NetworkingFundamental - Modulation / Demodulation • Amplitude Modulation where the Amplitude of the signal is varied • Frequency Modulation where the Frequency of the signal is varied • Phase Modulation where the Phase of the signal is shifted
  70. 70. CommServ – Education Division Datacom NetworkingFundamental - Digitization • Is the Process of Converting an Analog Signal to Digital Format • A COder-DECoder performs this operation by applying Pulse Code Modulation algorithm • The CODEC may be placed at any point • A logarithmic (com-panding) scale is used to map the amplitude to its digital value • The PCM companding rules define: 255 amplitude levels, -law, in USA, Canada and Japan 256 amplitude levels, A-law, almost rest of the world
  71. 71. CommServ – Education Division Datacom NetworkingFundamental - Multiplexing Techniques • Time Division Multiplexing (TDM) – Conventional • Bit-Interleaved • Byte-Interleaved – Statistical (STDM) T S - 1 t f T S - 2 T S - 3 T S - 4 T S - 1 T S - 2 T S - 3 T S - 4 T S - 1 T S - 2 T S - 3 T S - 4 TDM
  72. 72. CommServ – Education Division Datacom NetworkingFundamental - Multiplexing Techniques • Frequency Division Multiplexing (FDM) (CATV is a good example) • Wavelength Division Multiplexing (WDM) (often used in optical data transmission) t f F C - 1 F C - 2 F C - 3 F C - 4 FDM
  73. 73. CommServ – Education Division Datacom NetworkingFundamental - Communication Modes • Simplex – data is transmitted in one direction only • Half Duplex – Data can be transmitted in both directions, but only in one direction at any given time • Full Duplex – Data is transmitted in both directions simultaneously
  74. 74. CommServ – Education Division Datacom NetworkingFundamental - Transmission Modes SYN character Bit stream of many characters Asynchronous Synchronous SYN character Stop bit Character Start bit
  75. 75. CommServ – Education Division Datacom NetworkingFundamental - Asynchronous communications
  76. 76. CommServ – Education Division Datacom NetworkingFundamental - Synchronous Transmission • The complete block of data is transmitted as a contiguous bit stream in frames • To enable the receiving device to stay in sync data is carefully encoded (bit sync) • frames are preceded by a reserved byte to ensure correct interpretation on byte boundaries (byte sync) • frames are preceded by synchronization bytes (frame sync)
  77. 77. CommServ – Education Division Datacom NetworkingFundamental - Error Control • Parity Bit Method – an additional bit is added to each tansmitted character to detect single bit errors • Even / Odd parity • Block sum check algorithms – two additional bits are added (row / column) to detect errors – two bit errors that escape the row parity checking, will be detected by this method
  78. 78. CommServ – Education Division Datacom NetworkingFundamental - Error Control Frame to be transmitted Calculated CRC value fInput data Output data Inputpolynomial
  79. 79. CommServ – Education Division Datacom NetworkingFundamental - Data Compression • Packed Decimal – Reduce the number of transmitted data (numbers 0-9 all have 011 in msb position) • Relative Encoding – Data that has only small differences between successive values, (send only the d-magnitude) • Character Suppression – Used for more general case • Huffman Coding – Statistical coding
  80. 80. CommServ – Education Division Datacom NetworkingFundamental - Network Topologies
  81. 81. CommServ – Education Division Datacom NetworkingFundamental - Protocols • A protocol is a set of rules that govern the behaviour of communicating parties • Protocols handle:  Format of the exchanged data  Type and order of the information  Timing  Sequencing  Error control  Flow Control
  82. 82. CommServ – Education Division Datacom NetworkingTraffic Case-82 Datacom Networking 5. Traffic Case Chapter Objectives –Describe at a high level the path a packet may take through a network
  83. 83. CommServ – Education Division Datacom NetworkingTraffic Case-83 So, what happens when you do this?
  84. 84. CommServ – Education Division Datacom NetworkingTraffic Case-84 Upper Layer Protocol into IP • This is the File Transfer Protocol (FTP), which is a higher- layer protocol (layers 5,6 & 7 of OSI model) • FTP is carried within an Internet Protocol (IP) packet
  85. 85. CommServ – Education Division Datacom NetworkingTraffic Case-85 Local Area Network Technologies • Your PC is connected to your office Local Area Network (LAN), through a Network Interface Card (NIC) • Typically, the LAN technology used is Ethernet
  86. 86. CommServ – Education Division Datacom NetworkingTraffic Case-86 Adapting IP to Ethernet • The information (IP) needs to be adapted to the network technology • In this case the information must be transmitted in Ethernet frames
  87. 87. CommServ – Education Division Datacom NetworkingTraffic Case-87 The Hub • Likely the first device your frame will encounter is a hub – an Ethernet repeater • This hub simply repeats the signal and sends it on
  88. 88. CommServ – Education Division Datacom NetworkingTraffic Case-88 The LAN Switch • Likely the next device your frame will encounter is an Ethernet switch, also called a LAN switch • This LAN switch forwards on your Ethernet frame intelligently on the basis of it’s Ethernet address
  89. 89. CommServ – Education Division Datacom NetworkingTraffic Case-89 A Typical Office Network
  90. 90. CommServ – Education Division Datacom NetworkingTraffic Case-90 The Router • A router’s job is to take in IP packets and work out the next best hop for that packet based on the router’s internal routing tables
  91. 91. CommServ – Education Division Datacom NetworkingTraffic Case-91 IP Forwarding
  92. 92. CommServ – Education Division Datacom NetworkingTraffic Case-92 Layer 3 – Layer 2 Interaction • Consider a router with Ethernet and ATM interfaces
  93. 93. CommServ – Education Division Datacom NetworkingTraffic Case-93 Destination Server The final router knows that the destination IP device is directly connected to it The server will return the requested files to the source – the same process in reverse
  94. 94. CommServ – Education Division Datacom NetworkingEthernet Datacom Networking 7. Ethernet Concept Chapter Objectives –Describe naming conventions used with Ethernet –Describe the structure of a MAC address –Describe the CSMA/CD principle
  95. 95. CommServ – Education Division Datacom NetworkingEthernet LAN Technologies • Ethernet – By far the most widely used LAN technology today (95%+) – Available in 10Mbps, 100Mbps and 1000Mbps flavours • Token Ring – Old IBM standard – Workstations connected to rings, token passing concept – Rings were available at speeds of 4Mbit/s and 16Mbit/s • Fiber Distributed Data Interface (FDDI) – LAN Fiber backbone technology, used 100Mbit/s ring – No longer likely to be implemented in a new network • Asynchronous Transfer Mode (ATM) – Extensively deployed WAN technology, can be deployed in LANs – However, Ethernet is a far more cost effective LAN technology
  96. 96. CommServ – Education Division Datacom NetworkingEthernet Ethernet Evolution Ethernet Design Goals – Simplicity – Efficient use of shared resources – Ease of reconfiguration and maintenance – Compatibility – Low cost 1972 1996 Gigabit standard (802.3z) VLANs (802.1Q) 1000BaseT (802.3ab) 198 0 Ethernet V1 DIX - V2 in 82 1983 1990 10Base-T (802.3i) 10BaseF (Fiber) 1993 802.3z study group formed to standardize Gigabit Ethernet 19981985 IBM ships first Token Ring LAN IEEE 802.3 Standard 81-83 Fast Ethernet (802.3u) 1995 1997 Full Duplex (802.3x) 1973 Invention accredited to Robert Metcalfe- Patent 1977
  97. 97. CommServ – Education Division Datacom NetworkingEthernet IEEE 802 Family Architecture IEEE 802.3 IEEE 802.4 IEEE 802.5 IEEE 802.6 Physical IEEE 802.2 Internet Transport Upper IEEE 802.x Link 802.1 Internetworking 802.2 Logical Link Control (LLC) 802.3 CSMACD 802.4 Token Bus 802.5 Token Ring 802.6 Metropolitan Area Networks 802.7 Broadband Tech Advisory Group 802.8 Fiber Optic Tech Advisory Group 802.9 Integrated Voice&Data Networks 802.10 Network Security 802.11 Wireless Networks 802.12 Demand Priority Access LAN's
  98. 98. CommServ – Education Division Datacom NetworkingEthernet Ethernet Naming Conventions
  99. 99. CommServ – Education Division Datacom NetworkingEthernet 10BaseT Specifications • 10BaseT – 2 pairs of Cat 3 UTP – By far the most widely used specification • 10BaseF – 2 strands of MMF • 10Base2 – Thin coaxial or “Thinnet” (Dead) • 10Base5 – Thick coaxial or “Thicknet” (Dead) • 10Broad36 – Coaxial (Dead)
  100. 100. CommServ – Education Division Datacom NetworkingEthernet MAC Address Format 7 0- 7 0- 7 0- 7 0- 7 0- 7 0- octet order bit order
  101. 101. CommServ – Education Division Datacom NetworkingEthernet Ethernet Principle – CSMA/CD • CS = Carrier Sense – Listen until no carrier is sensed, then transmit after a delay • MA = Multiple Access – Designed for a broadcast environment – Every station hears every frame • CD = Collision Detection – Listen for a collision while you transmit
  102. 102. CommServ – Education Division Datacom NetworkingEthernet Ethernet Operation – CSMA
  103. 103. CommServ – Education Division Datacom NetworkingEthernet Ethernet Operation – CD
  104. 104. CommServ – Education Division Datacom NetworkingEthernet Ethernet Collisions – More Detail The adapters have to hear the collision while they are still transmitting They then transmit a 32-bit jam signal They wait a random time before retransmission If there are repeated collisions the adapter tries again, up to a a maximum of 16 times – Uses ―truncated binary exponential backoff‖ algorithm
  105. 105. CommServ – Education Division Datacom NetworkingEthernet Ethernet, Logical vs Physical
  106. 106. CommServ – Education Division Datacom NetworkingEthernet Datacom Networking 8. Ethernet Frame Chapter Objectives –Identify the characteristics of the following Ethernet frame types: •Ethernet Version 2 •IEEE 802.3 Novell Raw •IEEE 802.3 Standard (with LLC) •IEEE 802.3 SNAP
  107. 107. CommServ – Education Division Datacom NetworkingEthernet Chapter Objectives • After completing this chapter you will be able to: – Identify the characteristics of the following Ethernet frame types: • Ethernet Version 2 • IEEE 802.3 Novell Raw • IEEE 802.3 Standard (with LLC) • IEEE 802.3 SNAP
  108. 108. CommServ – Education Division Datacom NetworkingEthernet Ethernet Version 2 Frame (DIX) Network Data Link Control Physical
  109. 109. CommServ – Education Division Datacom NetworkingEthernet Examples of Ethernet Types E-Type Value NetWare 8137 XNS 0600, 0807 IP 0800 IP (VINES) 0BAD, 80C4 ARP 0806 RARP 8035 DRP 6003 LAT 6004 LAVC 6007 ARP (ATalk) 80F3
  110. 110. CommServ – Education Division Datacom NetworkingEthernet IEEE 802.3 Frame - Novell ―RAW‖
  111. 111. CommServ – Education Division Datacom NetworkingEthernet IEEE 802.3 Frame – with LLC (Standard Frame) Network Logical Link Control Physical Media Access Control
  112. 112. CommServ – Education Division Datacom NetworkingEthernet IEEE 802.3 Frame – SNAP Network SNAP Physical LLC MAC
  113. 113. CommServ – Education Division Datacom NetworkingEthernet Ethernet Frames Compared
  114. 114. CommServ – Education Division Datacom NetworkingEthernet Determining Ethernet Frame Types
  115. 115. CommServ – Education Division Datacom NetworkingEthernet Datacom Networking 9. Ethernet Device Chapter Objectives –Describe collision domains and broadcast domains –Describe how a hub, bridge and switch operate –Identify where a crossover cable is used –Describe the concept of Virtual LANs (VLANs)
  116. 116. CommServ – Education Division Datacom NetworkingEthernet Chapter Objectives • After completing this chapter you will: – Describe collision domains and broadcast domains – Describe how a hub, bridge and switch operate – Identify where a crossover cable is used – Describe the concept of Virtual LANs (VLANs)
  117. 117. CommServ – Education Division Datacom NetworkingEthernet Broadcasts Ethernet inherently supports broadcasts Broadcast mechanism is used frequently  Example ARP – Address Resolution Protocol A Broadcast Domain is all devices that will see a broadcast frame
  118. 118. CommServ – Education Division Datacom NetworkingEthernet Ethernet Devices
  119. 119. CommServ – Education Division Datacom NetworkingEthernet Hubs A hub is a simple OSI layer 1 device: a hub just repeats the incoming signal
  120. 120. CommServ – Education Division Datacom NetworkingEthernet
  121. 121. CommServ – Education Division Datacom NetworkingEthernet
  122. 122. CommServ – Education Division Datacom NetworkingEthernet Crossover Cables A ―crossover‖ or ―crossed‖ cable may be used to directly connect two Ethernet devices – Transmit/Receive reversed at one end – Crossover cables can be made or bought
  123. 123. CommServ – Education Division Datacom NetworkingEthernet Connecting Hubs Hubs may be connected or ―cascaded‖ – Connected hubs behave like one ―big‖ hub
  124. 124. CommServ – Education Division Datacom NetworkingEthernet Transparent Bridging
  125. 125. CommServ – Education Division Datacom NetworkingEthernet Bridges and Switches
  126. 126. CommServ – Education Division Datacom NetworkingEthernet
  127. 127. CommServ – Education Division Datacom NetworkingEthernet
  128. 128. CommServ – Education Division Datacom NetworkingEthernet
  129. 129. CommServ – Education Division Datacom NetworkingEthernet
  130. 130. CommServ – Education Division Datacom NetworkingEthernet LAN Switch Operation • Flooding • Learning • Forwarding • Filtering • User filtering
  131. 131. CommServ – Education Division Datacom NetworkingEthernet LAN Switch Operation • Having learned about destination addresses on the network the switch will forward frames intelligently on the basis of their MAC address
  132. 132. CommServ – Education Division Datacom NetworkingEthernet Full-Duplex Ethernet
  133. 133. CommServ – Education Division Datacom NetworkingEthernet
  134. 134. CommServ – Education Division Datacom NetworkingEthernet
  135. 135. CommServ – Education Division Datacom NetworkingEthernet
  136. 136. CommServ – Education Division Datacom NetworkingEthernet
  137. 137. CommServ – Education Division Datacom NetworkingEthernet Virtual LANs (VLANs) • A VLAN is a logical grouping of nodes (clients and servers) residing in a common broadcast domain • The broadcast domain has been artificially created within a LAN switch – standard 802.3ac LAN Switch OFF ON OFF ON VLAN #1 - 5 workstations or repeaters VLAN #2 - 11 workstations or repeaters VLAN #3 - 6 workstations or repeaters VLAN #4 - 10 workstations or repeaters
  138. 138. CommServ – Education Division Datacom NetworkingEthernet VLAN Example -1
  139. 139. CommServ – Education Division Datacom NetworkingEthernet VLAN Example -2
  140. 140. CommServ – Education Division Datacom NetworkingEthernet
  141. 141. CommServ – Education Division Datacom NetworkingEthernet
  142. 142. CommServ – Education Division Datacom NetworkingEthernet
  143. 143. CommServ – Education Division Datacom NetworkingEthernet
  144. 144. CommServ – Education Division Datacom NetworkingFast Ethernet- Datacom Networking 10. Fast Ethernet Chapter Objectives –Identify the physical specifications for Fast Ethernet –Define auto-negotiation –Understand how to interwork 10Mbit/s Ethernet and Fast Ethernet
  145. 145. CommServ – Education Division Datacom NetworkingFast Ethernet- Fast Ethernet Essentials • 10BaseT and 100BaseT – Both use CSMA/CD – Frame formats and frame lengths the same – Usually deployed over Category 5 UTP – Interconnections made with hubs, switches, routers etc. – Standard defined by IEEE 802.3u
  146. 146. CommServ – Education Division Datacom NetworkingFast Ethernet- Fast Ethernet vs 10BaseT Ethernet • 10BaseT vs 100BaseT – Transmits 10 times as much data in the same time – New physical standards – Interframe gap .96 microseconds instead of 9.6 microseconds (unchanged at 96 bit times)
  147. 147. CommServ – Education Division Datacom NetworkingFast Ethernet- 100BaseT Specifications • 100BaseTX – 2 pairs of Cat 5 UTP or Cat 1 STP – By far the most widely used specification (95%+) • 100BaseFX – 2 strands of SMF or MMF • 100BaseT4 – 4 pairs of Cat 3/4/5 UTP • 100BaseT2 – 2 pairs of Cat 3/4/5 UTP
  148. 148. CommServ – Education Division Datacom NetworkingFast Ethernet- Matching Interfaces
  149. 149. CommServ – Education Division Datacom NetworkingFast Ethernet- Auto-Negotiation 10 or 100? Full or half? Then, AUTO-NEGOTIATE! Useful if unsure what you‘re plugging in to - AND when upgrading to a 100BASE-T hub ?? Switch or Hub Algorithm used to negotiate common data service Common RJ-45 connector for 1 of 8 services Fast link pulses (FLP) similar to link integrity (LI) Hub/NIC adjust speed to highest common mode Order: 1. 1000BaseT FDX 2. 100BaseT2 FDX 3. 100BaseT2 HDX 4. 100BaseTX FDX 5. 100BaseT4 6. 100BaseTX 7. 10BaseT FDX 8. 10BaseT
  150. 150. CommServ – Education Division Datacom NetworkingFast Ethernet- Flow Control HDX - Switch generates collision FDX - Switch generates pause frame
  151. 151. CommServ – Education Division Datacom NetworkingGigabit Datacom Networking 11. Gigabit Ethernet Chapter Objectives –Identify the physical specifications for Gigabit Ethernet –Describe carrier extend –Describe frame bursting
  152. 152. CommServ – Education Division Datacom NetworkingGigabit Gigabit Ethernet Essentials • Latest extension to Ethernet • 1000 Mbit/s - 10 times faster than fast Ethernet • Compatible with existing Ethernet
  153. 153. CommServ – Education Division Datacom NetworkingGigabit Gigabit Carrier Extend P DA SA L/T Data FSSDS LLC Carrier Extend 448 bytes 64 previous minimum + 448 carrier extend = 512 minimum frame size Minimum frame size = 512 bytes
  154. 154. CommServ – Education Division Datacom NetworkingGigabit Frame Bursting • Frame Bursting is a means to reduce the Inefficiency of Carrier Extension • The first frame is transmitted using the normal procedures for gigabit Ethernet. • A frame burst timer is started to allow transmissions of up to 64 Kbits. • If additional frames are queued for transmission and the 64 Kbit timer has not expired, two things happen – The first frame is followed by carrier extend – The next frame is transmitted
  155. 155. CommServ – Education Division Datacom NetworkingGigabit Gigabit Ethernet Specifications • 1000BaseLX – 2 strands of SMF or MMF • 1000BaseSX – 2 strands of SMF • 1000BaseCX – 2 pairs of twinax • 1000BaseT – 4 pairs of Cat 5 UTP
  156. 156. CommServ – Education Division Datacom NetworkingGigabit Ethernet Comparison 512 Bytes64 Bytes64 BytesMin Frame Size 1518 Bytes1518 Bytes1518 BytesMax Frame Size 16 tries16 tries16 triesAttempt Limit 96 bit times96 bit times96 bit timesInter Frame Gap Fast Ethernet 802.3u Ethernet, 802.3 Parameter Gigabit Ethernet, 802.3z 48 bits48 bits48 bitsAddress Size
  157. 157. CommServ – Education Division Datacom NetworkingWAN-157 Datacom Networking 13. WAN Concepts Chapter Objectives –Define circuit switching and packet switching –Define SVCs and PVCs –Identify HDLC protocols and describe where they are used
  158. 158. CommServ – Education Division Datacom NetworkingWAN-158 Circuit Switching and Packet Switching • Circuit Switching – In a circuit switched network, a dedicated communications path is established between two terminals through the nodes of the network and for information transfer • Packet Switching – In this case it is not necessary to dedicate transmission capacity along a path through the network. Rather, data is sent out in a sequence of small chunks, called packets. Each packet is passed through the network from node to node along some path leading from the source to the destination.
  159. 159. CommServ – Education Division Datacom NetworkingWAN-159 A B A B A B A B A B A B A B Circuit Switching Packet Switching Info Info Info Info CS vs. PS for different applications
  160. 160. CommServ – Education Division Datacom NetworkingWAN-160 Leased Line and Dial-up • Leased line – With a leased line connection, a data user has a permanent dedicated transmission path which can be end to end across the network, locally, nationally or internationally. • Dial-up – This method is used for modem to modem data communication over the public switched telephone network (PSTN). Source and destination must have compatible modems.
  161. 161. CommServ – Education Division Datacom NetworkingWAN-161 Virtual Circuits, PVC and SVC • Virtual Circuit – Appears to be a separate physical circuit to the user, but in fact is part of a shared pool of resources • Permanent Virtual Circuit (PVC) – PVC is a continuously dedicated virtual circuit • Switched Virtual Circuit (SVC) – SVC is a temporary virtual circuit established and maintained only for the duration of a data transfer session
  162. 162. CommServ – Education Division Datacom NetworkingWAN-162 Datalink Layer Review • A data link layer protocol only provides services on a point-to-point, physical link. • It’s up to a higher layer protocol to provide end-to-end services.
  163. 163. CommServ – Education Division Datacom NetworkingWAN-163 HDLC, Derivatives and Variations Used by Frame Relay technology LAPF Error-correcting modems (specified as part of V.42) LAPM ISDN D channel and Frame Relay LAPD Current X.25 implementationsLAPB Early X.25 implementationsLAP UsesHDLC Subset
  164. 164. CommServ – Education Division Datacom NetworkingATM-164 Datacom Networking 14. ATM Chapter Objectives –Understand the concept of ATM –Describe how an ATM switch works –Describe where ATM is used in a Network
  165. 165. CommServ – Education Division Datacom NetworkingATM-165 ATM Essentials • Flexible bearer technology (2Mbit/s – 2.5Gbit/s) • Connection-orientated • Uses fixed-size cells • Able to guarantee Quality of Service (QoS) • A multiservice technology: both voice and data traffic can be carried on an ATM network
  166. 166. CommServ – Education Division Datacom NetworkingATM-166 ATM connections • In ATM a connection must be set up from source to destination before traffic can flow
  167. 167. CommServ – Education Division Datacom NetworkingATM-167 The ATM Cell • Fixed cell size • ATM switches read the cell header only, any information in the payload flows through the network transparently
  168. 168. CommServ – Education Division Datacom NetworkingATM-168 channel 1 channel 5 channel 1 empty cell channel 1 channel 7 channel 1 channel 2 Cell Labelled multiplexing
  169. 169. CommServ – Education Division Datacom NetworkingATM-169 Asynchronous? Transfer Mode
  170. 170. CommServ – Education Division Datacom NetworkingATM-170 The principle of ATM switching ATM payload A 2 payload B 7 payload B 14 payload A 18
  171. 171. CommServ – Education Division Datacom NetworkingATM-171 ATM Multiplexing
  172. 172. CommServ – Education Division Datacom NetworkingATM-172 Constant bit rate Data bursts Variable bit rate Segmentation Addressing Multiplexing Cell buffers Segmentation and Multiplexing of different Broadband Services
  173. 173. CommServ – Education Division Datacom NetworkingATM-173 ATM Connections • Many ways of setting up the connections: – Permanent Virtual Circuit (PVC) – Switched Virtual Circuit (SVC) • Many types of connections: – Constant Bit Rate (CBR) – Variable Bit Rate (VBR) – Available Bit Rate (ABR) – Unspecified Bit Rate (UBR) • Virtual connections can be of any bandwidth
  174. 174. CommServ – Education Division Datacom NetworkingATM-174 ATM Connections • Connections are virtual channels – Permanent (PVC) – Switched (SVC)
  175. 175. CommServ – Education Division Datacom NetworkingATM-175 ATM‘s Physical Layer ATM Layer Physical Layer Adaptation Layer PMD TC SAR CS Layer two Layer one
  176. 176. CommServ – Education Division Datacom NetworkingATM-176 ATM Interface References Public Networks Private Networks Public NNI B-ICI Public NNI Private NNI Public UNI Public UNI Private UNI Private UNI Public UNI Public UNI
  177. 177. CommServ – Education Division Datacom NetworkingATM-177 The Physical Interfaces Supported • E1 2.048 Mbit/s, T1 1.544 Mbit/s • E3 34 Mbit/s, DS3 45 Mbit/s • UTP-25 25 Mbit/s • STS-1 51.84 Mbit/s • TAXI 100 Mbit/s • UTP- 5 I55.52 Mbit/s • STM-1, OC3 155.52 Mbit/s • STM-4, OC12 622.08 Mbit/s • STM-16, OC48 2.488 Gbit/s • STM-64, OC192 10 Gbit/s - work in progress
  178. 178. CommServ – Education Division Datacom NetworkingATM-178 SDH/SONET • The base standard defined to support ATM is: – European/world standard • Synchronous Digital Hierarchy (SDH) – American standard • Synchronous Optical Network (SONET) • The two systems are identical at transmission rates of 155 Mbps and above
  179. 179. CommServ – Education Division Datacom NetworkingATM-179 SONET / SDH Topology Section ADM Line Path ADM ADM Repeaters Inserted Data Dropped Data Repeaters Inserted Data Dropped Data
  180. 180. CommServ – Education Division Datacom NetworkingATM-180 Physical Implementation of SDH • Physical aspects of SDH/SONET – Fibre • single mode – Preferred connection to operator connection • multimode – Used for private ATM networks, for example, a university campus – UTP • Category 5 – Used among workgroups – To replace traditional LANs with ATM
  181. 181. CommServ – Education Division Datacom NetworkingATM-181 ATM Layer ATM Layer Physical Layer Adaptation Layer PMD TC SAR CS Layer two Layer one
  182. 182. CommServ – Education Division Datacom NetworkingATM-182 ATM Cell Format VPI (high order) VCI - 1VPI (low order) VCI - 2 VCI - 3 Payload type CLP Header error control Payload (48 octets) bit order
  183. 183. CommServ – Education Division Datacom NetworkingATM-183 UNI Cell Header 48-octet data field GFC VPI VPI VCI VCI VCI PTI HEC 8 1 1st Octet 2nd Octet 3rd Octet 4th Octet 5th Octet Bits CLP
  184. 184. CommServ – Education Division Datacom NetworkingATM-184 NNI Cell Header 48-octet data field VPI VPI VCI VCI VCI PTI CLP HEC 8 1 1st Octet 2nd Octet 3rd Octet 4th Octet 5th Octet Bits
  185. 185. CommServ – Education Division Datacom NetworkingATM-185 Generic Flow Control • Locally significant only (at UNI) – Any value will be overwritten by the switch • Two modes of operation: – Controlled mode – Uncontrolled mode • Currently only uncontrolled mode is defined – Uncontrolled GFC = 0000 48-octet data field VPI VPI VCI VCI VCI PTI CLP HEC GFC
  186. 186. CommServ – Education Division Datacom NetworkingATM-186 Virtual Path Identifier • Identifies this cell’s path • 8 bits available at the UNI • 12 bits available at the NNI – 256/4096 possible simultaneous paths – Maximum number of usable bits is negotiable between user and network 48-octet data field VCI VCI VCI PTI CLP HEC VPI VPI GFC ‘Real’ physical link VPI 57 VPI 68
  187. 187. CommServ – Education Division Datacom NetworkingATM-187 Virtual Channel Identifier • Identifies this cell’s channel • 16 bits available at the UNI & NNI – 65,536 possible simultaneous channels per path – Maximum number of useable bits is negotiable on a per-path basis VPI 57 VPI 68 VCI 39 VCI 40 VCI 38 VCI 39 VPI 68 VPI 68 VCI 39 VCI44 VCI 40 VCI 41 Physical Interfaces 4- octet data field PTI CLP HEC VPI VPI GFC VCI VCI VCI
  188. 188. CommServ – Education Division Datacom NetworkingATM-188 Virtual Paths Multiple channels destined for a common location can be quickly and simply switched by the network if they share a common VPI channels 131 145 117 channels 131 145 117
  189. 189. CommServ – Education Division Datacom NetworkingATM-189 Reserved Virtual Connections • The following VPI/VCI combinations have been reserved: – VPI = 0 VCI = 0 to 15 ITU-T – VPI = 0 VCI = 16 to 31 ATM Forum – VPI = ALL VCI = 1 to 5 • In practice, carriers regard VCIs 0 to 31 as reserved for all VPIs
  190. 190. CommServ – Education Division Datacom NetworkingATM-190 Payload Type Identifier PTI Coding (MSB first) Interpretation User data cell, congestion not experienced, SDU type = 0 User data cell, congestion not experienced, SDU type = 1 User data cell, congestion experienced, SDU type = 0 User data cell, congestion experienced, SDU type = 1 Segment OAM F5 flow-related cell End-to-end OAM F5 flow-related cell Resource management cell Reserved for future functions 000 001 010 011 100 101 110 111 48-octet data field VPI VPI VCI VCI VCI CLP HEC GFC PTI
  191. 191. CommServ – Education Division Datacom NetworkingATM-191 Congestion Control • Bit 2 of the PTI may be used to indicate to the destination that congestion has taken place in the network • The bit is called Explicit Forward Congestion Indicator (EFCI) • This will occur when switches are discarding cells with CLP =1 48-byte data field VPI VPI VCI VCI VCI CLP HEC GFC PTI EFCI
  192. 192. CommServ – Education Division Datacom NetworkingATM-192 Cell Loss Priority • CLP operates independently on each active VPI/VCI • A switch may flip CLP from 0 to 1, for example, if traffic on a VPI/VCI exceeds the maximum agreed sustainable cell rate CLP = 0 CLP = 0 CLP = 1 CLP = 1 Private UNI Private NNI Public UNI Public NNI 48-octet data field VPI VPI VCI VCI VCI HEC GFC PTI CLP
  193. 193. CommServ – Education Division Datacom NetworkingATM-193 Header Error Check • The HEC is performed on the header only – Supports forward correction of single-bit errors – Supports detection of multiple-bit errors • Faulty cells are discarded – At the UNI: • Error detection is mandatory • Error correction is optional • The HEC is generated/verified at the TC part of the physical layer 48-octet data field VPI VPI VCI VCI VCI CLP GFC PTI HEC
  194. 194. CommServ – Education Division Datacom NetworkingATM-194 Virtual Paths and Channels ATM Switch Virtual Channel Switch Virtual Path Switch VCI1 VCI2 VCI3 VCI4 VCI1 VCI2 VCI3 VCI4 VCIa VCIb VCIa VCIb VPI1 VPI2 VPI3 VPI1 VPI2 VPI4 VPI5 VPI5
  195. 195. CommServ – Education Division Datacom NetworkingATM-195 The Switch Map ATM Cell ATM Cells VPI/VCI = A/B VPI/VCI = X/Y 1 2 Switch Map (1) VPI VCI Interface VPI VCI A B 2 X Y - - - - - VPI/VCI is of LOCAL Significance Only
  196. 196. CommServ – Education Division Datacom NetworkingATM-196 ATM Switching • ATM cells are being switched along a predefined connection
  197. 197. CommServ – Education Division Datacom NetworkingATM-197
  198. 198. CommServ – Education Division Datacom NetworkingATM-198
  199. 199. CommServ – Education Division Datacom NetworkingATM-199 The Adaptation Layer ATM Layer Physical Layer Adaptatio n Layer PMD TC SAR CS Layer two Layer one
  200. 200. CommServ – Education Division Datacom NetworkingATM-200 QoS Service Catagories • CBR Constant Bit Rate • VBR-RT Variable Bit Rate - Real Time • VBR-NRT Variable Bit Rate - Non-Real Time • ABR Available Bit Rate • UBR Unspecified Bit Rate • GFR Guaranteed Frame Rate (later)
  201. 201. CommServ – Education Division Datacom NetworkingATM-201 ATM Service Classes • Classes as defined by ITU-T rec. I 362 Class A Class B Class C Class D Timing between source and destination Required Not required Bit rate Constant Variable Connection mode Connection-oriented Connectionless AAL 1 AAL 2 AAL 3 AAL 4 AAL 5 Relevant Adaptation Layer
  202. 202. CommServ – Education Division Datacom NetworkingATM-202 General Principles of Adaptation Adaptation Layer SAR CS Higher layer data H H The use of a CS is not required by all AALs Etc. H T H T H T
  203. 203. CommServ – Education Division Datacom NetworkingATM-203 Usage of Adaptation Layer • AAL is used to adapt a source application to ATM – ATM switching takes place in the ATM Layer.
  204. 204. CommServ – Education Division Datacom NetworkingATM-204 AAL1 Segmentation and Reassembly sublayer Protocol Data Unit (SAR PDU) Payload, 47 bytes (376 bits) Header, 5 bytes SNP SN 44 SN, Sequence Number, 3 bits are used to detect loss of cells SNP, Sequence Number Protection
  205. 205. CommServ – Education Division Datacom NetworkingATM-205 ATM Adaptation Layer type 1 Payload Information for: •Lost cell detection •Synchronization •Support of structured Circuit Emulation 1 octet47 octets Real time, constant bit rate stream (e.g. PCM Speech)
  206. 206. CommServ – Education Division Datacom NetworkingATM-206 AAL 1
  207. 207. CommServ – Education Division Datacom NetworkingATM-207 AAL 2
  208. 208. CommServ – Education Division Datacom NetworkingATM-208 AAL 2
  209. 209. CommServ – Education Division Datacom NetworkingATM-209 AAL2 Segmentation And Reassemble sublayer Protocol Data Unit (SAR PDU) Header, 5 bytes LI CID 8 CID, Channel Identity LI, Length Indicator UUI, User-to-user Indicator HEC, Header Error Control PayloadPayloadPayload UUIHEC 8 STF 655 STF, Start Field
  210. 210. CommServ – Education Division Datacom NetworkingATM-210 AAL2 demultiplexed to AAL2U Header, 5 bytesPayloadPayloadPayload Payload Payload Payload AAL2 AAL 2U
  211. 211. CommServ – Education Division Datacom NetworkingATM-211 AAL5 (SEAL)
  212. 212. CommServ – Education Division Datacom NetworkingATM-212 AAL5, variable bit rate
  213. 213. CommServ – Education Division Datacom NetworkingATM-213 AAL5 Trailer
  214. 214. CommServ – Education Division Datacom NetworkingATM-214 AAL5 Transmission • AAL5 makes use of the PTI field in ATM cell header – Bit 1 = 1 indicates this cell carries the AAL5 trailer 48-byte data field VPI VPI VCI VCI VCI CLP HEC GFC PTI
  215. 215. CommServ – Education Division Datacom NetworkingATM-215 The use of AALs ATM AAL1 ATM AAL5 PCM (voice) IP (64KB max.) 48 octet ATM SDUs 53 octet ATM PDUs AAL1 ATM AAL5 AAL ATM ATM ATM AAL ATM
  216. 216. CommServ – Education Division Datacom NetworkingATM-216 ATM Applications – Large Core Networks
  217. 217. CommServ – Education Division Datacom NetworkingATM-217 Site 2Site 1 Transport Layer Network Control Layer Signaling User Plane RNC TDM Network PCM 64 kbps AMR coding 12 kbps WCDMA Transport • Aggregation of server nodes in the Control Layer TSC Server MSC Server Q.BICC N-ISUP RANAP Iu MGW GCPGCP TRA • M-MGw build the Transport Layer AAL2 Switch AAL2 Switches Q.AAL2 Q.AAL2 • Bandwidth efficient transport using “Codec at the edge” • Local Switching TDM Network
  218. 218. CommServ – Education Division Datacom NetworkingATM-218 ATM Based Signaling MAP-ATM TCAP MAP/CAP SCCP MTP3b SSCF-NNI ATM L1 AAL5 SSCOP SGSN <---> HLR 3G MSC <--> HLR HLR <--> VLR MSC <--> MSC RANAP-ATM RANAP SCCP MTP3b SSCF-NNI ATM L1 AAL5 SSCOP MSC MA <--> RNC MSC server <--> RNC SGSN <---> RNC Q.AAL2-ATM Q.AAL2 MTP3b SSCF-NNI ATM L1 AAL5 SSCOP GCP-ATM GCP MTP3b SSCF-NNI ATM L1 AAL5 SSCOP MSC server <---> MGW BICC/ISUP-ATM BICC/ISUP MTP3b SSCF-NNI ATM L1 AAL5 SSCOP MSC server <---> MSC server TSC server <--> PSTN MSC MA <---> RNC C-MGw <--> RNC C-MGw <--> C-MGw RNC <--> RNC RNSAP-ATM RNSAP SCCP MTP3b SSCF-NNI ATM L1 AAL5 SSCOP RNC <---> RNC
  219. 219. CommServ – Education Division Datacom NetworkingFrame Relay- Datacom Networking 15. Frame Relay Chapter Objectives –Understand the concept of Frame Relay –Describe how a Frame Relay switch works –Describe where Frame Relay is used in a Network
  220. 220. CommServ – Education Division Datacom NetworkingFrame Relay- Frame Relay Essentials • WAN packet switching technology, preceded ATM • Typically implemented at speeds from 56kbit/s to 2Mbit/s (Can go to speeds of 45Mbit/s) • Supports PVCs (SVCs are supported, but generally not used) • Uses variable-length frames to transfer data • Has some built in traffic control mechanisms
  221. 221. CommServ – Education Division Datacom NetworkingFrame Relay- Frame (LAPF) Format
  222. 222. CommServ – Education Division Datacom NetworkingFrame Relay-
  223. 223. CommServ – Education Division Datacom Networking Frame Relay Terms DLCI 21 DLCI 23 DLCI 22 DLCI 31 DLCI 32 DLCI 33 S 0 Frame Relay Switch Token Ring SDLC FRAD Definitions DLCI: Data Link Connection Identifier CIR : Committed Information Rate Bc : Committed burst in bits Be : Excess burst in bits FECN: Forward Explicit Congestion Notify BECN: Backward Explicit Congestion Notify DE: Discard Eligible Router Frame Relay Switch Maps DLCIs to form a PVC Controls each PVC‘s CIR, Bc, Be Congestion Notification: FECN, BECN Provides Accounting and Monitoring Router
  224. 224. CommServ – Education Division Datacom NetworkingFrame Relay- Frame Relay Switching • Frame Relay Frames are being switched along a predefined connection
  225. 225. CommServ – Education Division Datacom NetworkingFrame Relay- Congestion Control • FECN – Forward Explicit Congestion Notification • BECN – Backward Explicit Congestion Notification • DE – Discard Eligibility 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 Byte 1 Byte 2 DLCI(msb) DLCI(lsb)C/R EA EADE F E C N B E C N
  226. 226. CommServ – Education Division Datacom NetworkingFrame Relay- Congestion Notification
  227. 227. CommServ – Education Division Datacom NetworkingFrame Relay- Network Congestion Recovery Committed Information Rate (CIR) Maximum Information Rate Guaranteed transmission Transmit if possible DE = 1 Discard all excess
  228. 228. CommServ – Education Division Datacom Networking Frame Relay Illustration • Committed Information Rate (CIR) • Port speed (PIR) • Permanent Virtual Circuits (PVCs) Free if Available Traffic Time Peak CIR What You Pay for { {
  229. 229. CommServ – Education Division Datacom NetworkingFrame Relay- Performance Model Frame 1 DE=0 Frame 2 DE=0 Frame 3 DE=0 Frame 1 DE=0 Frame 2 DE=0 Frame 3 DE=0 Frame 4 DE=1 Frame 1 DE=0 Frame 2 DE=0 Frame 3 DE=1 Frame 4 DISCARDED Time Time Time Number of bits transmitte d Number of bits transmitte d Number of bits transmitte d Discard region DE = 1 region DE = 0 region Discard region DE = 1 region DE = 0 region Discard region DE = 1 region DE = 0 region Bc+Be Bc Bc+Be Bc Bc+Be Bc
  230. 230. CommServ – Education Division Datacom NetworkingFrame Relay- FR Applications – Corporate LAN Interconnect
  231. 231. CommServ – Education Division Datacom NetworkingFrame Relay-
  232. 232. CommServ – Education Division Datacom Networking interface s 0 encapsulation frame-relay ! interface s 0.1 point-to-point ip address 172.16.1.1 255.255.255.0 frame-relay interface-dlci 42 ! interface s 0.2 point-to-point ip address 172.16.4.1 255.255.255.0 frame-relay interface-dlci 53 ! Interface s 0.3 point-to-point ip address 172.16.2.10 255.255.255.0 frame-relay interface-dlci 59 interface s 0 encapsulation frame-relay ! interface s 0.1 point-to-point ip address 172.16.2.18 255.255.255.0 frame-relay interface-dlci 36 ! interface s 0.2 point-to-point ip address 172.16.3.25 frame-relay interface-dlci 46 Frame Relay Configuration Example DLCI 36 Frame Relay Network 172.16.3.0 BA DLCI 42 172.16.1.0 DLCI 59 172.16.2.0 DLCI 53 172.16.4.0 DLCI 46
  233. 233. CommServ – Education Division Datacom Networking interface s 0 encapsulation frame-relay ! interface s 0.1 multipoint ip address 172.16.1.1 255.255.255.0 frame-relay interface-dlci 300 frame-relay interface-dlci 212 frame-relay interface-dlci 437 interface s 0 encapsulation frame-relay ! interface s 0.1 point-to-point ip address 172.16.1.18 255.255.255.0 frame-relay interface-dlci 36 Frame Relay BA 172.16.1.2 172.16.1.3 D C DLCI 36 Frame Relay Multipoint Example
  234. 234. CommServ – Education Division Datacom NetworkingFrame Relay-
  235. 235. CommServ – Education Division Datacom NetworkingX25-235 Datacom Networking 16. X25 Chapter Objectives •Understand the concept X.25 •Describe the structure of a LAPB frame •Describe the structure of an X.25 packet
  236. 236. CommServ – Education Division Datacom NetworkingX25-236 X.25 Essentials  Old WAN packet switching technology, preceded both Frame Relay and ATM  Designed to run over error-prone physical links so contains extensive error checking mechanisms  X.25 typically implemented over low speed links <64K - (low speed by today‘s standards)  X.25 used extensively with older proprietary systems - banking terminals, control links for telephone exchanges
  237. 237. CommServ – Education Division Datacom NetworkingX25-237 X.25 and OSI Reference Model Application Presentation Session Transport Network Data Link Physical Physical Frame Packet X.25 Protocol Suite Upper Layer Protocols
  238. 238. CommServ – Education Division Datacom NetworkingX25-238 X.25 Interface User Process Packet Link Access Link Access PhysicalPhysical User Process Packet Multi-channel Logical Interface LAPB Link Level Logical Interface Physical Interface Physical DLC Network OSI-RM User Data User Data Layer 3 Header X.25 Packet LAPB Header Layer 3 Header User Data FCS LAPB Frame 10101110111...... Node-A Node-B Flag
  239. 239. CommServ – Education Division Datacom NetworkingX25-239 X.25 WAN DTE DCE DCE Packet Switching Network Leased line Physical DTE Physical DCE
  240. 240. CommServ – Education Division Datacom NetworkingX25-240 X.25 WAN (contd) DTE Packet Switching Network X 25 context is between DTE and Packet switched network (DCE) DTE DTE X 25 X 25 Logical DCE at layer 2 / 3 Logical DTE at layer 2 / 3 DCE DCE Transparent at layer 2 / 3 Logical DTE at layer 2 / 3
  241. 241. CommServ – Education Division Datacom Networking Flag Address Information FCS FlagControl 0 1 1 1 1 1 1 0 0 1 1 1 1 1 1 0 Flag Flags
  242. 242. CommServ – Education Division Datacom Networking Flag Address Information FCS FlagControl 0N(R) N(S) I: 7 6 5 4 3 2 1 0 F P S:N(R) 0 1 7 6 5 4 3 2 1 0 U:P F X X 1 1 7 6 5 4 3 2 1 0 P F X X X X X 01 or 03 Address and Control
  243. 243. CommServ – Education Division Datacom NetworkingX25-243 Information frames I Information nr p ns 0 Supervisory frames RR Receiver Ready nr p/f 0 0 0 1 RNR Receiver Not Ready nr p/f 0 1 0 1 REJ Reject nr p/f 1 0 0 1 Unnumbered frames SABM Set asynchronous balanced mode 0 0 1 p 1 1 1 1 UA Unnumbered acknowledgement 0 1 1 f 0 0 1 1 DISC Disconnect 0 1 0 p 0 0 1 1 DM Disconnected mode 0 0 0 f 1 1 1 1 FRMR Frame Reject 1 0 0 f 0 1 1 1 LAPB Commands and Responses
  244. 244. CommServ – Education Division Datacom NetworkingX25-244 LAPB Operation 1 SABM SABM UA UA Info nr=0 ns=0 Info nr=0 ns=0 Info nr=1 ns=0 Info nr=1 ns=2 Info nr=1 ns=1 Info nr=1 ns=0 Info nr=1 ns=1 Info nr=1 ns=3 Info nr=1 ns=2 Info nr=1 ns=3 RR nr=4 RR nr=4 Info nr=4 ns=1 Info nr=4 ns=1 DCE DTE Info nr=2 ns=4 Info nr=2 ns=4
  245. 245. CommServ – Education Division Datacom NetworkingX25-245 LAPB Operation 2 Info nr=2 ns=7 Info nr=2 ns=7 REJ nr=6 DCE DTE Info nr=2 ns=5 Info nr=2 ns=4 Info nr=2 ns=6 Info nr=2 ns=5 Info nr=2 ns=4 Ignored as CRC incorrect Info nr=2 ns=0 Info nr=2 ns=0 REJ nr=6 Info nr=2 ns=6 Info nr=2 ns=6 Info nr=2 ns=7 Info nr=2 ns=0 Info nr=2 ns=0 Info nr=2 ns=7 Info nr=1 ns=2 Info nr=1 ns=2 REJ frame acknowledges up to frame 5 XX
  246. 246. CommServ – Education Division Datacom NetworkingX25-246 LAPB Operation 3 Info nr=2 ns=7 p=0 Info nr=2 ns=7 p=0 DCE DTE Info nr=2 ns=5 p=0 Info nr=2 ns=4 p=0 Info nr=2 ns=6 p=0 Info nr=2 ns=5 p=0 Info nr=2 ns=4 p=0 Info nr=2 ns=4 p=1 Info nr=2 ns=4 p=1 T1 timer T1 timer Info nr=2 ns=4 p=1 Info nr=2 ns=4 p=1 Info nr=2 ns=4 p=1 Info nr=2 ns=6 p=0 T1 timer N 2 times Info nr=2 ns=4 p=1
  247. 247. CommServ – Education Division Datacom Networking Logical Channel Numbers (LCNs) LCN LCN LCN LCN Logical DTE Logical DCE Logical DTELogical DTE Logical DCE Logical DTE
  248. 248. CommServ – Education Division Datacom Networking LCNs (contd) LCN 5 LCN 8 LCN 45 LCN 19 LCN 9 LCN 9
  249. 249. CommServ – Education Division Datacom Networking General Format Identifier Q D 01 Modulo 8 10 Modulo 128 11 Extensions 00 Reserved 8 7 6 5 4 3 2 1Bits Byte 1 LCGNModulo GFI normal L D Long Address indicator Call Request packets only 8 7 6 5 4 3 2 1Bits Byte 1 LCGNModulo GFI Extended addressing
  250. 250. CommServ – Education Division Datacom Networking Byte 1 2 3 12345678 Logical Channel Number GFI Bits Packet Type Identifier Logical Channel Group Number Packet Layer Header 16 Logical Channel Group Numbers 256 Logical Channel Numbers in each group A Logical channel may be identified by LCN or by LCGN + LCN Logical channel 0 = LCGN 0 , LCN 0 Logical channel 1025 = LCGN 4 , LCN 1
  251. 251. CommServ – Education Division Datacom Networking Packet Header Call request / incoming call 0 0 0 0 1 0 1 1 Call accept / call connected 0 0 0 0 1 1 1 1 Clear request / Clear indication 0 0 0 1 0 0 1 1 Clear confirmation 0 0 0 1 0 1 1 1 Data pr m ps 0 RR pr 0 0 0 0 1 RNR pr 0 0 1 0 1 REJ pr 0 1 0 0 1 Interrupt 0 0 1 0 0 0 1 1 Interrupt confirmation 0 0 1 0 0 1 1 1 Reset request / Reset indication 0 0 0 1 1 0 1 1 Reset confirmation 0 0 0 1 1 1 1 1 Restart request/restart indication 1 1 1 1 1 0 1 1 Restart confirmation 1 1 1 1 1 1 1 1 Diagnostic 1 1 1 1 0 0 0 1
  252. 252. CommServ – Education Division Datacom Networking Call Setup Call request Incoming Call Call AcceptCall connected
  253. 253. CommServ – Education Division Datacom Networking General Format Identifier Logical Channel Group Number Logical Channel Number Packet Type Identifier Calling DTE Address Length Called DTE Address Length Called DTE Address Field BCD - 2 digits / octet Variable length (15 digits max) Facility Field Length 12345678Bits Call Request, Incoming call, Call Accepted, Call Connected Facility Field codes and values Variable length Calling DTE Address Field BCD - 2 digits / octet Variable length (15 digits max)
  254. 254. CommServ – Education Division Datacom NetworkingX25-254 X.25 Operation DTE A DTE B A Initiates a virtual call to B Incoming Call Call Accepted Data pr=0 ps=0 Data pr=0 ps=1 Data pr=2 ps=0 RR pr = 1 Call Request Call Connected Data pr=0 ps=0 Data pr=0 ps=1 Data pr=3 ps=0 Network RR pr=1 RR pr=2 Data pr=1 ps=3 Data pr=1 ps=2 Data pr=1 ps=3 Data pr=1 ps=2 Acknowledgement from local DCE Acknowledgement from local node Call established Data transfer stage Acknowledgement changed by local node for packet with ps=2 Packet delayed at local node until ACK has been received from remote DTE
  255. 255. CommServ – Education Division Datacom NetworkingX25-255 X.121 Addressing DNIC Data Network Identification Code (DCC + NI) DCC Data Country Code (3 digits) NI Network Identifier (1 digit) NTN Network Terminal Number (max10 digits incl SA) SA Sub-address 234 2 19201005 234 2 19201004 74 240 2 00451 272 4 30000200 310 6 000715 DNIC NI NTN SA
  256. 256. CommServ – Education Division Datacom NetworkingPPP-256 Datacom Networking 17. PPP Chapter Objectives –Describe how a PPP frame structure –Describe the function of the Link Control Protocol (LCP) –Describe the function of the Network Control Protocol (NCP) –Describe where PPP is used in a Network
  257. 257. CommServ – Education Division Datacom NetworkingPPP-257 PPP Essentials • Very widely-used standard for transporting layer 3 datagrams (especially IP) over point-to-point links (rfc 1661) • PPP replaces the older Serial Line Interface Protocol (SLIP) • PPP is comprised of: – Encapsulation method – Link Control Protocol (LCP) – Network Control Protocol (NCP) • Often referred to as “self-configuring”
  258. 258. CommServ – Education Division Datacom NetworkingPPP-258
  259. 259. CommServ – Education Division Datacom NetworkingPPP-259 PPP Frame Format
  260. 260. CommServ – Education Division Datacom NetworkingPPP-260
  261. 261. CommServ – Education Division Datacom NetworkingPPP-261 Link Control Protocol (LCP) Functions • Determine encapsulation format options • Negotiate optimal packet size • Terminate the link • Authenticate the identity of the peer on the link [ PAP or CHAP ] (optional) • Negotiate PPP Multilink data compression (optional) • Link quality monitoring (optional)
  262. 262. CommServ – Education Division Datacom NetworkingPPP-262 Network Control Protocols (NCPs) • NCPs are a series of independently-defined protocols that encapsulate network layer protocols • Examples: TCP/IP, DECnet, AppleTalk, IPX…
  263. 263. CommServ – Education Division Datacom NetworkingPPP-263 PPP Logical Flow LCP Link DEAD Start Up State NCPNegotiate Options Bind NCP Last Last Terminate Data Exchange Fail authentication OpenLCP phase NCP phase Open State
  264. 264. CommServ – Education Division Datacom NetworkingPPP-264
  265. 265. CommServ – Education Division Datacom NetworkingPPP-265
  266. 266. CommServ – Education Division Datacom NetworkingPPP-266 PPP Applications
  267. 267. CommServ – Education Division Datacom NetworkingModems-267 Datacom Networking 18. Modems Chapter Objectives –Describe the function of a modem –Identify modem standards and associated speeds –Describe where modems are used in a Network
  268. 268. CommServ – Education Division Datacom NetworkingModems-268 Chapter Objectives • After completing this chapter you will be able to: – Describe the function of a modem – Identify modem standards and associated speeds – Describe where modems are used in a Network
  269. 269. CommServ – Education Division Datacom NetworkingModems-269 Modem – MOdulation and DEModulation
  270. 270. CommServ – Education Division Datacom NetworkingModems-270 Modem Standards Rec. Speed (bit/s) Transmission Mode PSTN LL 2W LL 4W Back-up via PSTN Mod. Method V.21 300 Asynchronous (A) FD FD FSK V.23 1200/600 A and S HD HD FD * FSK V.22 1200/600 A and S FD FD * DPSK V.22bis V.22f.bk 2400/1200 A and S FD FD * QAM V.26bis 2400/1200 Synchronous (S) HD HD FD * DPSK V.26ter 2400/1200 A and S FD FD * DPSK V.27ter V.26bisf.bk 4800/2400 S HD HD FD * DPSK V.29 9600/7200/4800 A and S FD QAM V.32 9600/4800 A and S FD FD * QAM/TCM V.33 14400/12000 S FD QAM/TCM V.34 28800 S FD TCM V.34bis 28800/31200/33600 S FD TCM Baseband 2400/1800/1200 7200/4800/3600 19200/14400/9600 A and S HD FD V.90 56000 to the end user 33600 from the end user S Asymetric PCM
  271. 271. CommServ – Education Division Datacom NetworkingModems-271 LAPM Frame Format
  272. 272. CommServ – Education Division Datacom NetworkingModems-272 Modem Applications
  273. 273. CommServ – Education Division Datacom NetworkingISDN-273 Datacom Networking 19. ISDN Chapter Objectives –Describe the concept of ISDN –Identify the reference points in an ISDN network –Identify the differences between primary and basic rate ISDN –Describe where ISDN is used in network
  274. 274. CommServ – Education Division Datacom NetworkingISDN-274 ISDN Essentials • Full services, digital, end-to-end network • Narrowband ISDN and Broadband ISDN (B-ISDN is ATM-based) • ISDN based on 64Kbit/s channels • Two channel types: Bearer (B) Channel and Data (D) Channel – B channel for user traffic, uses PPP – D channel signalling and control, uses LAPD
  275. 275. CommServ – Education Division Datacom NetworkingISDN-275 ISDN BRI Reference Model TE1 NT2 NT1 Terminal Adapter U Interface T Interface S Interface R Interface To Telco To Telco TE2
  276. 276. CommServ – Education Division Datacom NetworkingISDN-276 PRI Frame Format for E1/T1 7 6 5 4 3 2 1 07 6 5 4 3 2 1 00 B1 D-Channel B31Framing 7 6 5 4 3 2 1 256 bits/125 microseconds (2.048Mbps) E1 Signaling +31+0 +1 +16 Data Data F 7 6 5 4 3 2 1 07 6 5 4 3 2 1 0 B1 B2 B23 D-Channel 24th Channel 193 bits/125 microseconds (1.544Mbps) T1
  277. 277. CommServ – Education Division Datacom NetworkingISDN-277 Basic Rate Interface (BRI) B1 B2 D 64Kbs 64Kbs 16Kbs 2B + 1D
  278. 278. CommServ – Education Division Datacom NetworkingISDN-278 Primary Rate Interface (PRI) 64Kbs 64Kbs : : B1 64Kbs 64Kbs 64Kbs : B2 D 23B + 1D (USA) 30B + 1D (EISDN) B22 or 29B23 or 30
  279. 279. CommServ – Education Division Datacom NetworkingISDN-279 LAPD Format
  280. 280. CommServ – Education Division Datacom NetworkingISDN-280 Types of ISDN Connections • Circuit Switched • Packet Switched • Frame Mode • Semi-permanent
  281. 281. CommServ – Education Division Datacom NetworkingISDN-281 ISDN Applications
  282. 282. CommServ – Education Division Datacom NetworkingxDSL-282 Datacom Networking 20. xDSL Chapter Objectives –Describe the concept of xDSL –Identify the speeds of common xDSL standards –Describe where xDSL is used in a network
  283. 283. CommServ – Education Division Datacom NetworkingxDSL-283 Copper Access
  284. 284. CommServ – Education Division Datacom NetworkingxDSL-284 xDSL Technologies • Asymmetric Digital Subscriber Line (ADSL) • Rate Adaptive Digital Subscriber Line (RADSL) • High-bit-rate Digital Subscriber Line (HDSL) • Symmetrical Digital Subscriber Line (SDSL) • Very-high-data-rate Digital Subscriber Line (VDSL)
  285. 285. CommServ – Education Division Datacom NetworkingxDSL-285 DSL Types Technology Data Rate Mode Distance (ft) Distance (m) ISDL/ISDN 128Kbps Duplex 18000 5400 HDSL 2.048Mbps 1.544Mbps Duplex Duplex 12000 3600 SDSL 2.048Mbps 1.544Mbps Duplex Duplex 10000 3000 ADSL 6.144Mbps 640Kbps Downstream Upstream 12000 3600 RADSL 0.32-9Mbps Downstream Depends on data rate VDSL 12.96Mbps 25.92Mbps 51.84Mbps 1.5 – 6Mbps Downstream Upstream 4500 3000 1000 1350 900 300
  286. 286. CommServ – Education Division Datacom NetworkingxDSL-286 ADSL standards and bandwidth 8,1 / 1,5 Mbps Annex A (POTS) 8,1 / 1,8 Mbps Annex B (ISDN) 8 / 3.4 Mbps ‗Annex J‘ (POTS) Scenario ... ADSL ADSL2 ADSL2+ ADSL2++ VDSL1/2 DMT 13,4 / 1,6 Mbps Annex A (POTS) 11,5 / 1,9 Mbps Annex B (ISDN) 5,7 / 1,0 Mbps Annex L (POTS) 11,5 / 3,5 Mbps Annex M (POTS) 28,7 / 1,6 Mbps Annex A (POTS) 26,8 / 1,9 Mbps Annex B (ISDN) 26,8 / 3,5 Mbps Annex M (POTS)
  287. 287. CommServ – Education Division Datacom NetworkingxDSL-287 ITU G.992.1 - ADSL • ITU G.992.1 (ADSL) is implemented from EDA 1.1 • The following ADSL annexes are available: ISDN DS ADSL Annex B f [kHz] ADSL Annex A f [kHz] DS POTS US US Variable frequency spectrum POTS f [kHz] DS ADSL Annex M US 25 80 138 276 1104552
  288. 288. CommServ – Education Division Datacom NetworkingxDSL-288 ITU G.992.3 - ADSL2 • ITU G.992.3 (ADSL2) is implemented from EDA 1.3 • The following ADSL2 annexes are available: ISDN DS ADSL2 Annex B f [kHz] ADSL2 Annex A f [kHz] DS POTS US US Variable frequency spectrum POTS f [kHz] DS ADSL2 Annex M US 25 80 138 276 1104 DS POTS US 552 f [kHz] ADSL2 Annex L
  289. 289. CommServ – Education Division Datacom NetworkingxDSL-289 ITU G.992.5 - ADSL2+ • ITU G.992.5 (ADSL2+) is implemented from EDA 2.0 • New frequency spectrum compared with G992.1 & G992.3 • The following ADSL2+ annexes are available: ISDN DS ADSL2+ Annex B f [kHz] POTS f [kHz] ADSL2+ Annex A f [kHz] DS DS POTS US ADSL2+ Annex M US 25 80 138 276 2208 US Variable frequency spectrum
  290. 290. CommServ – Education Division Datacom NetworkingxDSL-290 ADSL2/ADSL2+ Facts • ADSL2 Boosts performance – 13 Mbps / 3 Mbps (DS/US) • ADSL2 provides service over longer loop lengths – Approx. 500 m more compared with G992.1 – Annex L even more on long loop lengths • ADSL2+ Boosts performance even more – 28 Mbps / 3 Mbps (DS/US) • ADSL2+ relevant for loop lengths up to 2 km Length, Km1 Km 2 Km 3 Km 4 Km 5 Km 6 Km 8 13 ADSL2 ADSL2+ 28 Data Rate, Mbps Annex L is relevant here 7 Km ADSL
  291. 291. CommServ – Education Division Datacom NetworkingxDSL-291 xDSL Applications
  292. 292. CommServ – Education Division Datacom NetworkingxDSL-292 Multiple downstream tunnels with same content Video service via PPP tunnels Channel 1 Channel 2 Set-top Box Channel 1 Set-top Box Channel 2 Set-top Box Channel 2 Router/ BRAS Video Service Provider IP DSLAM
  293. 293. CommServ – Education Division Datacom NetworkingxDSL-293 Video service via IGMP Supports IGMP snooping Supports IP Multicast Only one downstream for each channel Channel 1 Channel 2 Set-top Box Channel 1 Set-top Box Channel 2 Set-top Box Channel 2 Router/ BRAS Video Service Provider IP DSLAM
  294. 294. CommServ – Education Division Datacom NetworkingSDH SONET- Datacom Networking 21. SDH & SONET Chapter Objectives –Describe the differences between PDH and SDH/SONET –Identify the speeds associated with SDH/SONET –Describe where SDH/SONET is used in a Network
  295. 295. CommServ – Education Division Datacom NetworkingSDH SONET- PDH Systems DS0 @ 64k 1.5Mb 6Mb 45Mb 274MbX 4 X 7 X 6 2Mb 8Mb 34Mb 565Mb140Mb X30 X 4 X 4 X 4
  296. 296. CommServ – Education Division Datacom NetworkingSDH SONET- PDH Multiplexing and Demultiplexing • With PDH everything must be de-multiplexed to extract a single signal! – Motivation for development of SDH/SONET
  297. 297. CommServ – Education Division Datacom NetworkingSDH SONET- PDH/SDH and SONET SDH/SONET – Higher bandwidth, easier to manage, backwards- compatible with PDH
  298. 298. CommServ – Education Division Datacom NetworkingSDH SONET- SONET and SDH Frames
  299. 299. CommServ – Education Division Datacom NetworkingSDH SONET- SONET and SDH Frames – Overhead
  300. 300. CommServ – Education Division Datacom NetworkingSDH SONET-
  301. 301. CommServ – Education Division Datacom NetworkingSDH SONET- Overhead Layers ADM or DCS REGREG PTEPTE Section SectionSection Section Line Line Path Path Termination Section Termination Line Termination Section Termination Path Termination Service (DS1, DS3 ..) Mapping and Demapping Service Mapping and Demapping PTE Path Terminating Element REG Regenerator ADM Add-Drop Multiplexer DCS Digital Cross-Connect System
  302. 302. CommServ – Education Division Datacom NetworkingSDH SONET- SDH Multiplexing Structure Pointer SOH SOH STM-1 VC-4 C-4 260 9 P O H 140 Mbit/sC-4VC-4STM-1
  303. 303. CommServ – Education Division Datacom NetworkingSDH SONET- SDH Multiplexing Structure x 1 x 3 x 1 x 7 x 3 x 1x N STM-N AUG AU4 VC4 C4 C3 C2 C12 C11 139,264 kbit/s 44,736 34,368 kbit/s 6,312 kbit/s 2,048 kbit/s 1,544 kbit/s VC3 VC2 VC12 VC11 TU3 TU2 TU12 TUG2 TUG3 Aligning Mapping Multiplexing STM Synchronous Transport Mode AUG Administrative Unit Group AU Administrative Unit TUG Tributary Unit Group TU Tributary Unit VC Virtual Container C Container AU3 VC3 x 3 x 7 TU11TU11 x 4
  304. 304. CommServ – Education Division Datacom NetworkingSDH SONET-
  305. 305. CommServ – Education Division Datacom NetworkingSDH SONET-
  306. 306. CommServ – Education Division Datacom NetworkingSDH SONET-
  307. 307. CommServ – Education Division Datacom NetworkingSDH SONET- SDH/SONET Equipment • Add-drop multiplexer – A multiplexer capable or extracting or inserting lower rate signals from a higher rate multiplexed signal without completely demultiplexing the signal • Digital Cross Connect – An electronic cross-connect which has access to lower-rate channels in higher-rate multiplexed signals and can cross-connect those channels • Regenerator (Repeater) – Device that restores a degraded digital signal for continued transmission
  308. 308. CommServ – Education Division Datacom NetworkingSDH SONET- SDH / SONET Acronyms This Graphic is the Property of Quill Training Services 9953.280 2488.320 622.080 155.520 51.840 STS-192 STS-48 STS-12 STS-3 STS-1 OC-192 OC-48 OC-12 OC-3 OC-1 STM-64 STM-16 STM-4 STM-1 SDH-64 SDH-16 SDH-4 SDH-1 Format Frame Level SDH ( Mbps ) Line Rate Format Frame Carrier Level Optical
  309. 309. CommServ – Education Division Datacom NetworkingSDH SONET-
  310. 310. CommServ – Education Division Datacom NetworkingSDH SONET- Applications of SDH/SONET
  311. 311. CommServ – Education Division Datacom NetworkingPOS-311 Datacom Networking 22. POS Chapter Objectives –Describe the concept of Packet Over SONET (POS) –Describe where POS is used in a Network
  312. 312. CommServ – Education Division Datacom NetworkingPOS-312
  313. 313. CommServ – Education Division Datacom NetworkingPOS-313 Packet Over SONET (POS) Essentials • POS = Packet over SONET or Packet over SDH • A standard for transmitting packets (primarily IP) over high speed SONET/SDH links • Consists of PPP over SONET or SDH – IP is carried within PPP • Works with all speed of SONET/SDH • Attractive solution for large ISP cores
  314. 314. CommServ – Education Division Datacom NetworkingPOS-314 IP over PPP over SDH/SONET
  315. 315. CommServ – Education Division Datacom NetworkingPOS-315
  316. 316. CommServ – Education Division Datacom NetworkingPOS-316
  317. 317. CommServ – Education Division Datacom NetworkingPOS-317 POS Applications – Large Core ISP Networks
  318. 318. CommServ – Education Division Datacom NetworkingPOS-318
  319. 319. CommServ – Education Division Datacom NetworkingMPLS-319 Datacom Networking 23. MPLS Chapter Objectives –Describe the concept of Multiprotocol Label Switching (MPLS) –Describe how MPLS devices work –Identify how MPLS is implemented with different technologies –Describe where MPLS is used in a Network
  320. 320. CommServ – Education Division Datacom NetworkingMPLS-320 Multiprotocol Label Switching Essentials • MPLS is an Internet Engineering Task Force (IETF) forwarding standard • Concept: – Packets entering the network are analysed and put into a forward equivalence class (FEC) – Forward equivalence classes are mapped to connections through the network – The packet is labelled according to which path it should take through the network – Packet is transferred though the network by switching on the label
  321. 321. CommServ – Education Division Datacom NetworkingMPLS-321
  322. 322. CommServ – Education Division Datacom NetworkingMPLS-322
  323. 323. CommServ – Education Division Datacom NetworkingMPLS-323
  324. 324. CommServ – Education Division Datacom NetworkingMPLS-324 MPLS Network Components Label Switching Router (LSR) deployed in the core of the network to perform high speed label switching Label Edge Router (LER) deployed at the edge of the network for connectivity to user networks. Also called ingress and egress LSRs.
  325. 325. CommServ – Education Division Datacom NetworkingMPLS-325
  326. 326. CommServ – Education Division Datacom NetworkingMPLS-326
  327. 327. CommServ – Education Division Datacom NetworkingMPLS-327
  328. 328. CommServ – Education Division Datacom NetworkingMPLS-328
  329. 329. CommServ – Education Division Datacom NetworkingMPLS-329
  330. 330. CommServ – Education Division Datacom NetworkingMPLS-330
  331. 331. CommServ – Education Division Datacom NetworkingMPLS-331 MPLS in Operation
  332. 332. CommServ – Education Division Datacom NetworkingMPLS-332 MPLS in Operation
  333. 333. CommServ – Education Division Datacom NetworkingMPLS-333 LER Functions
  334. 334. CommServ – Education Division Datacom NetworkingMPLS-334 LSR Functions
  335. 335. CommServ – Education Division Datacom NetworkingMPLS-335 MPLS Implementation • MPLS can be implemented as: • A Layer 3 (or “Pure IP”) solution – The Label is extra information attached to the IP header – LERs are edge routers running MPLS software – LSRs are core routers running MPLS software • An ATM solution – The Label is the VPI/VCI – LERs are edge routers running MPLS software – LSRs are ATM switches running MPLS software
  336. 336. CommServ – Education Division Datacom NetworkingMPLS-336 MPLS Label in a ―Pure IP‖ Solution
  337. 337. CommServ – Education Division Datacom NetworkingMPLS-337
  338. 338. CommServ – Education Division Datacom NetworkingMPLS-338 MPLS Label in an IP over ATM Solution
  339. 339. CommServ – Education Division Datacom NetworkingMPLS-339
  340. 340. CommServ – Education Division Datacom NetworkingMPLS-340
  341. 341. CommServ – Education Division Datacom NetworkingMPLS-341
  342. 342. CommServ – Education Division Datacom NetworkingMPLS-342
  343. 343. CommServ – Education Division Datacom NetworkingMPLS-343
  344. 344. CommServ – Education Division Datacom NetworkingMPLS-348 MPLS Applications – Large Backbone Networks
  345. 345. CommServ – Education Division Datacom NetworkingMPLS-349
  346. 346. CommServ – Education Division Datacom NetworkingMPLS-350
  347. 347. CommServ – Education Division Datacom NetworkingMPLS-351
  348. 348. CommServ – Education Division Datacom NetworkingInternet Datacom Networking 25. Internet Architecture Chapter Objectives –Describe the structure of the TCP/IP protocol suite
  349. 349. CommServ – Education Division Datacom NetworkingInternet Internet Protocols TCP IP Transport Layer RARP UDPOSPF EGP BGP ICMP IGMP RIP TELNET, FTP, TFTP, BOOTP, SMTP, HTTP, SNMP, NFS, NTP, , , Internet Layer ARP Type Code Protocol Number Port Number IEEE 802.2, PPP, LAPB, Ethernet, RS232, 802.3, 802.5, Upper Layer Link/Physical Layer
  350. 350. CommServ – Education Division Datacom NetworkingInternet Upper-Layer Protocols: End User and Utility Functions TCP IP Transport Layer RARP UDPOSPF EGP BGP ICMP IGMP RIP TELNET, FTP, TFTP, HTTP, SMTP SNMP, BOOTP/DHCP, DNS, NTP, RADIUS Internet Layer ARP Type Code Protocol Number Port Number IEEE 802.2, PPP, LAPB, Ethernet, RS232, 802.3, 802.5, Upper Layer Link/Physical Layer
  351. 351. CommServ – Education Division Datacom NetworkingInternet Transport Layer Protocols TCP IP Transport Layer RARP UDPOSPF EGP BGP ICMP IGMP RIP SNMP, BOOTP/DHCP, DNS, NTP, RADIUS, , , , Internet Layer ARP Type Code Protocol Number Port Number IEEE 802.2, PPP, LAPB, Ethernet, RS232, 802.3, 802.5, Upper Layer Link/Physical Layer
  352. 352. CommServ – Education Division Datacom NetworkingInternet Internet Layer Protocol: Internet Protocol TCP IP Transport Layer RARP UDPOSPF EGP BGP ICMP IGMP RIP SNMP, BOOTP/DHCP, DNS, NTP, RADIUS, , , , Internet Layer ARP Type Code Protocol Number Port Number IEEE 802.2, PPP, LAPB, Ethernet, RS232, 802.3, 802.5, Upper Layer Link/Physical Layer
  353. 353. CommServ – Education Division Datacom NetworkingInternet Anomalies TCP IP Transport Layer RARP UDPOSPF EGP BGP ICMP IGMP RIP SNMP, BOOTP/DHCP, DNS, NTP, RADIUS, , , , Internet Layer ARP Type Code Protocol Number Port Number IEEE 802.2, PPP, LAPB, Ethernet, RS232, 802.3, 802.5, Upper Layer Link/Physical Layer
  354. 354. CommServ – Education Division Datacom NetworkingInternet Sending and Receiving a Message Application specify: Upper Layer Protocol Internet address Upper Layer protocol: Build header for peer to describe format Specify Port number to select Application Transport Layer protocol: Build Header for peer to describe format Specify Protocol number to select proper Internet Layer (IP): Build header for peer to describe format Source and destination IP addresses Link Layer (unique for physical connection): Build header for peer to describe format Identify IP stack with Type Code number at IP address Transport Layer protocol
  355. 355. CommServ – Education Division Datacom NetworkingInternet Internet Society (ISOC) Specifications • All Internet standards specified by the IETF, a division of ISOC • Standards are called Request for Comments (RFCs) and are sequentially numbered • All standards available free from http://www.ietf.org • RFC search facility available at http://www.rfc-editor.org/
  356. 356. CommServ – Education Division Datacom NetworkingInternet Apps- Datacom Networking 26. Internet Applications Chapter Objectives –Describe how the Hypertext Transfer Protocol (HTTP) works –Describe how the Domain Name Service (DNS) works –Describe how the Simple Network Management Protocol (SNMP) works –Describe how the File Transfer Protocol (FTP) works –Describe how Telnet works
  357. 357. CommServ – Education Division Datacom NetworkingInternet Apps- Hypertext Transfer Protocol Architecture HTTP TCP IP Protocol 6 HTTP TCP IP Protocol 6 ServerClient Port 80 Port 80
  358. 358. CommServ – Education Division Datacom NetworkingInternet Apps- HTTP Operation Web client browser TCP port 80 hypertext links Web server
  359. 359. CommServ – Education Division Datacom NetworkingInternet Apps- Uniform Resource Locator (URL) scheme = http://, ftp://, telnet://, news:, mailto: , , , , , http://server.name/file.type scheme path=domain name or IP address search object
  360. 360. CommServ – Education Division Datacom NetworkingInternet Apps- Domain Name Service (DNS) rootunnamed intorgnetmilgoveducom ukau us geographically based domains: 2-letter country codes defined in ISO 3166 organizationally based domains: defined by Internet Registry (IR) IP Physical network DNS UDP Protocol 17 port 53
  361. 361. CommServ – Education Division Datacom NetworkingInternet Apps- File Transfer Protocol IP Physical network FTP TCP Protocol 6 port 21
  362. 362. CommServ – Education Division Datacom NetworkingInternet Apps- Telnet IP Physical network Telnet TCP Protocol 6 port 23
  363. 363. CommServ – Education Division Datacom NetworkingInternet Apps- Simple Network Management Protocol Architecture SNMP UDP IP Protocol 17 SNMP UDP IP Protocol 17 ManagerAgent Port 169 Port 169
  364. 364. CommServ – Education Division Datacom NetworkingInternet Apps- SNMP Management Manager Managed Resources Managed Node Agent MIB SNMP SNMP Operations Set, Get, GetResponse, GetNext, Trap
  365. 365. CommServ – Education Division Datacom NetworkingTransport Datacom Networking 27. Transport Layer Protocol Chapter Objectives –Describe how connection may be multiplexed –Define ports and sockets –Describe the differences between TCP and UDP –Describe the operation of TCP and UDP
  366. 366. CommServ – Education Division Datacom NetworkingTransport Multiplexing Connections Internet client server SMTP FTP HTTP SMTP FTP HTTP IP address X IP address Y destination port 25 source port 3000 destination port 21 source port 3001 destination port 80 source port 3002
  367. 367. CommServ – Education Division Datacom NetworkingTransport Connection Components Internet client server SMTP FTP HTTP SMTP FTP HTTP IP address X IP address Y destination port 25 source port 3000 destination port 21 source port 3001 destination port 80 source port 3002 socketsocket connection
  368. 368. CommServ – Education Division Datacom NetworkingTransport Transport Layer Protocols UDP IP TCP Upper Layer Protocols Physical network ports 617 protocols
  369. 369. CommServ – Education Division Datacom NetworkingTransport Transmission Control Protocol (TCP) Segment Format TCP Data +0 +4 bit order 01234567012345670123456701234567 octet +0 octet +1 octet +2 octet +3 octet order +8 +16 +20 source port destination port sequence number acknowledgement number check sum urgent pointer options (if any) padding window+12 hdr length reserved code bits

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