Uploaded on

 

More in: Technology , Business
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
772
On Slideshare
0
From Embeds
0
Number of Embeds
0

Actions

Shares
Downloads
43
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Komunikasi Data TKE 107 – 3 sks Bab 1 - 2 Protokol and Arsitektur
  • 2. A Communications Model
    • Source
      • generates data to be transmitted
    • Transmitter
      • Converts data into transmittable signals
    • Transmission System
      • Carries data
    • Receiver
      • Converts received signal into data
    • Destination
      • Takes incoming data
  • 3. Communications Tasks Flow control Network management Error detection and correction Security Exchange management Message formatting Synchronization Recovery Signal generation Routing Interfacing Addressing Transmission system utilization
  • 4. Simplified Communications Model - Diagram
  • 5. Simplified Data Communications Model
  • 6. Frame Relay
    • Packet switching systems have large overheads to compensate for errors
    • Modern systems are more reliable
    • Errors can be caught in end system
    • Most overhead for error control is stripped out
  • 7. Asynchronous Transfer Mode
    • ATM
    • Evolution of frame relay
    • Little overhead for error control
    • Fixed packet (called cell) length
    • Anything from 10Mbps to Gbps
    • Constant data rate using packet switching technique
  • 8. Local Area Networks
    • Smaller scope
      • Building or small campus
    • Usually owned by same organization as attached devices
    • Data rates much higher
    • Usually broadcast systems
    • Now some switched systems and ATM are being introduced
  • 9. LAN Configurations
    • Switched
      • Switched Ethernet
        • May be single or multiple switches
      • ATM LAN
      • Fibre Channel
    • Wireless
      • Mobility
      • Ease of installation
  • 10. Metropolitan Area Networks
    • MAN
    • Middle ground between LAN and WAN
    • Private or public network
    • High speed
    • Large area
  • 11. Networking Configuration
  • 12. Karakteristik
    • Langsung – Tak Langsung
    • Monolitik – Terstruktur
    • Simetris – Asimetris
    • Standard - Nonstandard
  • 13. Kebutuhan thd Protokol Arsitektur
    • Perpindahan data memerlukan prosedur yang komplek
    • Lebih baik bila dipecah dlm sub-sub task
    • Diimplementasikan dlm tumpukan layer
      • Tiap-tiap layer menyediakan fungsi-fungsi yang diperlukan untuk berkomunikasi dengan layer di atasnya
      • Memanfaatkan fungsi-fungsi yang disediakan layer di bawahnya
    • Peer layer berkomunikasi dengan layer
  • 14. Elemen kunci sebuah Protokol
    • Sintaks : format
    • Semantiks : info kontrol dan penanganan kesalahan
    • Timing : Kesesuaian kecepatan dan urutan
  • 15. Langsung – Tak Langsung
    • Langsung
      • Sistem membagi saluran point to point
      • Sistem membagi saluran multi-point
      • Data dapat lewat tanpa intervensi agen aktif
    • Tak Langsung
      • Switched networks
      • Internetworks atau internets
      • Transfer data bergantung pada entitas lain
  • 16. Monolitik - Terstruktur
    • Komunikasi adalah sebuah task yang kompleks
    • To complex for single unit
    • Terstruktur : melakukan ‘break down’ masalah ke dalam unit-unit yang lebih kecil
    • Struktur berlayer
  • 17. Simetrik - Asimetrik
    • Simetrik
      • Komunikasi antara peer entities
    • Asimetrik
      • Client/server
  • 18. Standard – Nonstandard
    • Protokol yang tidak standar dibuat untuk komputer-komputer dan task khusus
    • K sources dan L receivers menjadikan K*L protocols dan ada 2*K*L implementasi
    • Jika protokol bersama yang digunakan, ada K + L implementasi diperlukan
  • 19. Penggunaan Protokol Standard
  • 20. Fungsi
    • Enkapsulasi
    • Segmentasi(Fragmentasi) dan Reassembly
    • Connection control
    • Ordered delivery
    • Flow control
    • Error control
    • Addressing
    • Multiplexing
    • Transmission services
  • 21. Enkapsulasi
    • Penambahan informasi kontrol ke data
      • Informasi alamat
      • Kode Error-detecting
      • Kontrol Protocol
  • 22. Segmentasi (Fragmentasi)
    • Data blocks are of bounded size
    • Application layer messages may be large
    • Network packets may be smaller
    • Splitting larger blocks into smaller ones is segmentation (or fragmentation in TCP/IP)
      • ATM blocks (cells) are 53 octets long
      • Ethernet blocks (frames) are up to 1526 octets long
    • Checkpoints and restart/recovery
  • 23. Mengapa Fragmentasi?
    • Advantages
      • More efficient error control
      • More equitable access to network facilities
      • Shorter delays
      • Smaller buffers needed
    • Disadvantages
      • Overheads
      • Increased interrupts at receiver
      • More processing time
  • 24. Connection Control
    • Connection Establishment
    • Data transfer
    • Connection termination
    • May be connection interruption and recovery
    • Sequence numbers used for
      • Ordered delivery
      • Flow control
      • Error control
  • 25. Connection Oriented Data Transfer
  • 26. Ordered Delivery
    • PDUs may traverse different paths through network
    • PDUs may arrive out of order
    • Sequentially number PDUs to allow for ordering
  • 27. Flow Control
    • Done by receiving entity
    • Limit amount or rate of data
    • Stop and wait
    • Credit systems
      • Sliding window
    • Needed at application as well as network layers
  • 28. Error Control
    • Guard against loss or damage
    • Error detection
      • Sender inserts error detecting bits
      • Receiver checks these bits
      • If OK, acknowledge
      • If error, discard packet
    • Retransmission
      • If no acknowledge in given time, re-transmit
    • Performed at various levels
  • 29. Addressing
    • Addressing level
    • Addressing scope
    • Connection identifiers
    • Addressing mode
  • 30. Addressing level
    • Level in architecture at which entity is named
    • Unique address for each end system (computer) and router
    • Network level address
      • IP or internet address (TCP/IP)
      • Network service access point or NSAP (OSI)
    • Process within the system
      • Port number (TCP/IP)
      • Service access point or SAP (OSI)
  • 31. Address Concepts
  • 32. Addressing Scope
    • Global nonambiguity
      • Global address identifies unique system
      • There is only one system with address X
    • Global applicability
      • It is possible at any system (any address) to identify any other system (address) by the global address of the other system
      • Address X identifies that system from anywhere on the network
    • e.g. MAC address on IEEE 802 networks
  • 33. Connection Identifiers
    • Connection oriented data transfer (virtual circuits)
    • Allocate a connection name during the transfer phase
      • Reduced overhead as connection identifiers are shorter than global addresses
      • Routing may be fixed and identified by connection name
      • Entities may want multiple connections - multiplexing
      • State information
  • 34. Addressing Mode
    • Usually an address refers to a single system
      • Unicast address
      • Sent to one machine or person
    • May address all entities within a domain
      • Broadcast
      • Sent to all machines or users
    • May address a subset of the entities in a domain
      • Multicast
      • Sent to some machines or a group of users
  • 35. Multiplexing
    • Supporting multiple connections on one machine
    • Mapping of multiple connections at one level to a single connection at another
      • Carrying a number of connections on one fiber optic cable
      • Aggregating or bonding ISDN lines to gain bandwidth
  • 36. Transmission Services
    • Priority
      • e.g. control messages
    • Quality of service
      • Minimum acceptable throughput
      • Maximum acceptable delay
    • Security
      • Access restrictions
  • 37. OSI - The Model
    • A layer model
    • Each layer performs a subset of the required communication functions
    • Each layer relies on the next lower layer to perform more primitive functions
    • Each layer provides services to the next higher layer
    • Changes in one layer should not require changes in other layers
  • 38. The OSI Environment
  • 39. OSI as Framework for Standardization
  • 40. Layer Specific Standards
  • 41. Elements of Standardization
    • Protocol specification
      • Operates between the same layer on two systems
      • May involve different operating system
      • Protocol specification must be precise
        • Format of data units
        • Semantics of all fields
        • allowable sequence of PCUs
    • Service definition
      • Functional description of what is provided
    • Addressing
      • Referenced by SAPs
  • 42. OSI Layers (1)
    • Physical
      • Physical interface between devices
        • Mechanical
        • Electrical
        • Functional
        • Procedural
    • Data Link
      • Means of activating, maintaining and deactivating a reliable link
      • Error detection and control
      • Higher layers may assume error free transmission
  • 43. OSI Layers (2)
    • Network
      • Transport of information
      • Higher layers do not need to know about underlying technology
      • Not needed on direct links
    • Transport
      • Exchange of data between end systems
      • Error free
      • In sequence
      • No losses
      • No duplicates
      • Quality of service
  • 44. OSI Layers (3)
    • Session
      • Control of dialogues between applications
      • Dialogue discipline
      • Grouping
      • Recovery
    • Presentation
      • Data formats and coding
      • Data compression
      • Encryption
    • Application
      • Means for applications to access OSI environment
  • 45. Use of a Relay
  • 46. TCP/IP Protocol Suite
    • Dominant commercial protocol architecture
    • Specified and extensively used before OSI
    • Developed by research funded US Department of Defense (DARPA=Defense Advanced Research Project Agency) for ARPANET packet switchet network
    • Used by the Internet
  • 47. Physical Layer
    • Concerned with physical interface between computer and network
    • Concerned with issues like :
      • Karakteristik dari media transmisi
      • Level sinyal
      • Data rate
  • 48. Network Access Layer
    • Pertukaran data antara sebuah ‘end system’ dan ‘attached network’
    • Berkonsentrasi pada hal-hal “
      • Penyediaan alamat tujuan
      • Menyediakan layanan khusus seperti prioritas
      • Akses dan routing data melalui sebuah jaringan antaran ‘attached systems’
    • Membolehkan layer di atas untuk mengabaikan
    • Logical interface between end system and network
  • 49. Internet Layer (IP)
    • Fungsi routing melewati berbagai jaringan
    • Menggunakan protokol IP
    • Terimplementasikan di ‘end system’ dan router
    • Router menghubungkan dua network dan merelay data antar keduanya
  • 50. Transport Layer (TCP)
    • End to end transfer of data
    • May include reliability mechanism (TCP)
    • Hides detail of underlying network
  • 51. Application Layer
    • Menyediakan dukungan terhadap aplikasi user
    • Memerlukan modul-modul terpisah untuk tiap-tiap aplikasi
    • Communication between processes or applications
  • 52. PDUs in TCP/IP
  • 53. Some Protocols in TCP/IP Suite
  • 54. Transmission Control Protocol (TCP)
    • Menyediakan koneksi yang handal untuk transfer data antara aplikasi-aplikasi
    • Sebuah segmen TCP adalah unit protokol dasar
    • TCP melacak segmen-segmen antara entitas-entitas untuk penentuan durasi dari tiap koneksi
  • 55. TCP Header
  • 56. User Datagram Protocol (UDP)
    • Alternatif dari TCP
    • Tidak ada garansi
    • Tidak ada preservation of sequence
    • Tidak ada perlindungan terhadap duplikasi
    • Overhead minimal
    • Menambah alamat port ke IP
  • 57. UDP Header