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www.persistentsys.com       Dr. Vinton Cerf and Dr. Robert Kahn       Their Work and its Impact       R. Venkateswaran    ...
Agenda     Bio of Turing Award Recipients – Dr. Vinton Cerf and Dr.      Robert Kahn     History of the Internet     Ea...
ACKNOWLEDGMENTS:    This presentation has re-used slides and information from    the works of :    • Prof Raj Jain, Washin...
Dr. Vinton Cerf     Widely known as the “Father of the Internet”     Illustrious Career       Elected President of ACM ...
Dr. Robert Kahn     Helped design the Packet-Switched ARPANET     Illustrious Career       President & CEO of CNRI – Co...
The Internet – 40+ Years     First 20 Years : Internet 1.0       Trusted network used by Defense, Research and Academic ...
www.persistentsys.com           INTERNET 1.0© 2012 Persistent Systems Ltd
Problem addressed by Cerf & Kahn8                                       © 2012 Persistent Systems Ltd
Internetworking Objective    “…both economic and technical    considerations lead us to prefer that the    interface be as...
Internetworking Architecture                            Network Layer                            Gateways10               ...
Foundation for TCP & IP Protocols - I      Create a nonproprietary universal set of protocols      Standardized – non-Pa...
Foundation for TCP & IP Protocols - II      Process header (Port) – identify the end process that consumes the       info...
ARPANET13               © 2012 Persistent Systems Ltd
TCP/IP Layered Architecture ModelEnd         Application                                                        Applicatio...
www.persistentsys.com           Network Layer© 2012 Persistent Systems Ltd
IP : Protocol of choice for Network Layer      Packet-switched datagram network                                          ...
IP Network Design Philosophy      Keep the network simple        Simple network devices, intelligent end-systems       ...
IP: Minimalist Approach      Dumb network        IP provides minimal functionalities to support connectivity        Add...
Packet Switching                        Courtesy: William Stallings19                        © 2012 Persistent Systems Ltd
Circuit Switching                         Courtesy: William Stallings20                         © 2012 Persistent Systems ...
www.persistentsys.com           Transport Layer© 2012 Persistent Systems Ltd
User Datagram Protocol (UDP) – RFC768      UDP – unreliable, datagram-based protocol      Connectionless End-to-End Serv...
Transmission Control Protocol (TCP) –     RFC791      Designed to provide Reliable process-to-process communication      ...
Evolution of TCP                                                       1984              1975                             ...
TCP Through the 1990s                                     1994                 1996                                    T/T...
TCP Variants :      TCP-Tahoe:        implements the slow start, congestion avoidance, and fast retransmit         algor...
www.persistentsys.com           INTERNET 2.0           Internet goes Commercial© 2012 Persistent Systems Ltd
Key Events in early 90s      Tim-Berners Lee proposed the idea for the World Wide Web        Mosaic – first graphical we...
Some observations Demand for broadband access and growth  of bandwidth intensive apps fueling each  other Applications d...
Growth of the Internet                              Copyright: http://www.zakon.org/robert/internet/timeline/30           ...
Growth of the Internet                              Copyright: http://www.zakon.org/robert/internet/timeline/31           ...
Applications: network requirements           High                                    Streaming                 Interactive...
Evolution of Multi Service Networks      As Internet Usage increased, an evolved Next Generation Network       (NGN) arch...
www.persistentsys.com           BellHeads vs NetHeads© 2012 Persistent Systems Ltd
Ideological Differences               BellHeads                                   NetHeadsCircuit-switched Telco backgroun...
www.persistentsys.com           Asynchronous Transfer Mode (ATM)           Networks           BellHead view of NGN© 2012 P...
Bellheads view of NGN – ATM Networks      Packet switched network, but connection-oriented      Fixed size (53-byte) pac...
ATM Everywhere38                      © 2012 Persistent Systems Ltd
www.persistentsys.com           Challenge for the Netheads© 2012 Persistent Systems Ltd
Per-packet processing in an IP Router     1.   Accept packet arriving on an incoming link.     2.   Lookup packet destinat...
Lookup Rates Required     Optical     Line Rate   40 Byte Pkts Lookup     Interface   (Gbps)      (Mpps)       Rates (ns) ...
Routing Table Size                          Source: Geoff Huston, Internet Protocol Journal, Vol 4, No. 142               ...
Router Performance                           Source: Ipsilon Networks43                          © 2012 Persistent Systems...
www.persistentsys.com           Break-through for the Netheads © 2012 Persistent Systems Ltd
Routing vs Switching      Routing – based on address lookup and longest prefix match        Search and compare operation...
1996: Ipsilon’s IP Switching Concept      Hybrid: IP routing (control plane) + ATM switching (data plane)                 ...
Ipsilon’s Solution                           Source: Ipsilon Networks47                          © 2012 Persistent Systems...
Ipsilon’s IP Switching                              Courtesy: Shiv Kalyanaraman48                                 © 2012 P...
TCP/UDP Flow Statistics                                Source: Ipsilon Networks49                               © 2012 Per...
MPLS: Best of Both Worlds PACKET                                   CIRCUIT                       HYBRID             SWITCH...
www.persistentsys.com       Basics of MultiProtocol Label       Switching (MPLS)© 2012 Persistent Systems Ltd
MPLS – Multiprotocol Label Switching      Introduces a new fixed-length header (label) for the IP packet payload        ...
MPLS Header                            Label (20-bits)    CoS S      TTL             L2 Header   MPLS Header          IP P...
MPLS – Main Ideas      Separate forwarding information (label) from the content of IP header      Single forwarding para...
MPLS Terminology                                                             Connection Table                             ...
MPLS Terminology                                                               Egress                                     ...
MPLS Forwarding Model         Source                                         Egress                   Ingress             ...
MPLS Forwarding vs. IP Routing     Source                                                                     Destination ...
MPLS Forwarding Example                                                       MPLS Table                                  ...
MPLS - Summary      MPLS forwarding algorithm is simpler than IP forwarding algorithm        Fixed size header vs variab...
www.persistentsys.com           INTERNET 3.0           End of Network-Centric viewpoint© 2012 Persistent Systems Ltd
Some challenges with today’s Internet      Support for Mobility with TCP/IP not efficient      Security issues – viruses...
Challenges….      Network-centric (“Where”) approach not optimal for various applications        People-centric – “Who” ...
Future Research      Delay Tolerant Network Architecture      Content-Centric Networks      Software Defined Network (S...
www.persistentsys.com           Delay Tolerant Network© 2012 Persistent Systems Ltd
Delay Tolerant Networks (DTN)      DTNs Characterized by        Intermittent Connectivity        Extremely Long Delays ...
Delay Tolerant Network – Overlay Arch                         Source: http://www.cs.rice.edu/~scrosby/TA/comp620-s05/paper...
www.persistentsys.com           Content Centric Network© 2012 Persistent Systems Ltd
Content Centric Networks69                                © 2012 Persistent Systems Ltd
Content Centric Networks      Strategy – Figuring out the best path to deliver the content        Dynamic optimization  ...
www.persistentsys.com           Software Defined Network© 2012 Persistent Systems Ltd
SDN Architecture                                App      App    App    App                                                ...
Analogy with Computer Industry     Computer Industry                     Network Industry      Apps          Apps         ...
Software Defined Network74                                © 2012 Persistent Systems Ltd
Does this look familiar?75                                © 2012 Persistent Systems Ltd
www.persistentsys.com       THANK YOU       Email: venki@persistent.co.in© 2012 Persistent Systems Ltd
References      1. Prof Raj Jain’s home page - http://www.cse.wustl.edu/~jain/      2. Dr Shivkumar Kalyanaraman’s lecture...
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Life & Work of Dr. Vinton Cerf and Dr. Robert Kahn | Turing100@Persistent

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R Venkateswaran, CTO, Persistent Systems Ltd talks about the Life and Work of 2004 Turing Award Winners Vinton Cerf & Bob Kahn

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Transcript of "Life & Work of Dr. Vinton Cerf and Dr. Robert Kahn | Turing100@Persistent"

  1. 1. www.persistentsys.com Dr. Vinton Cerf and Dr. Robert Kahn Their Work and its Impact R. Venkateswaran CTO, Persistent Systems Ltd Email: venki@persistent.co.in© 2012 Persistent Systems Ltd
  2. 2. Agenda  Bio of Turing Award Recipients – Dr. Vinton Cerf and Dr. Robert Kahn  History of the Internet  Early years of Packet Switching  Evolution of Networking protocols over the 40 years  Future architectural options2 © 2012 Persistent Systems Ltd
  3. 3. ACKNOWLEDGMENTS: This presentation has re-used slides and information from the works of : • Prof Raj Jain, Washington Univ, St Louis • Dr. Shivkumar Kalyanaraman, IBM Research, India and ex-Professor at RPI • William Stallings – Data & Computer Communication • Video Interviews of Dr Cerf and Dr Kahn from ACM and other sources • Copyrighted material from Robert Zakon’s Internet Timeline3 © 2012 Persistent Systems Ltd
  4. 4. Dr. Vinton Cerf  Widely known as the “Father of the Internet”  Illustrious Career  Elected President of ACM in 2012  Chief Internet Evangelist, Google  Chair, ICANN  Senior VP at MCI, Worldcom  Worked at DARPA  Asst Prof at Stanford University  Awards and Recognition  ACM Turing Award Recipient – 2004  Presidential Medal of Freedom in 2005  Inducted into the Internet Hall of Fame, 2012  Personal:  Shares his birthday with Alan Turing4  Both he and his wife have a hearing impediment © 2012 Persistent Systems Ltd
  5. 5. Dr. Robert Kahn  Helped design the Packet-Switched ARPANET  Illustrious Career  President & CEO of CNRI – Corporation for National Research Initiatives  Worked at DARPA  Worked at BBN  Asst Prof at MIT  AT&T Bell Laboratories  Awards and Recognition  ACM Turing Award Recipient – 2004  National Medal of Technology, 1997  Presidential Medal of Freedom, 2005  Inducted into the Internet Hall of Fame, 2012  Personal:  Born on Dec 23, 19385 © 2012 Persistent Systems Ltd
  6. 6. The Internet – 40+ Years  First 20 Years : Internet 1.0  Trusted network used by Defense, Research and Academic Communities  Non-commercial  Popular applications: Email, FTP, Telnet  Next 20 Years : Internet 2.0  Commercial use  Multiple levels of ownership – leads to distrust and Security concerns  Wide range of use: Email, WWW, eCommerce, Multimedia  Key Identifier: IP Address (location, user identity)  Future : Internet 3.0  Centered around Users, Data Objects and Hosts  Service-Oriented  Builtin Security and Mobility support6 © 2012 Persistent Systems Ltd
  7. 7. www.persistentsys.com INTERNET 1.0© 2012 Persistent Systems Ltd
  8. 8. Problem addressed by Cerf & Kahn8 © 2012 Persistent Systems Ltd
  9. 9. Internetworking Objective “…both economic and technical considerations lead us to prefer that the interface be as simple and reliable as possible and deal primarily with passing data between networks using different packet switching strategies” V. G. Cerf and R. E. Kahn, 19749 © 2012 Persistent Systems Ltd
  10. 10. Internetworking Architecture Network Layer Gateways10 © 2012 Persistent Systems Ltd
  11. 11. Foundation for TCP & IP Protocols - I  Create a nonproprietary universal set of protocols  Standardized – non-Patented, no constraints or controls  Universal Addressing across different networks  Unique identification of hosts in the composite network  Information slices (packets) are transported from one host to another via the Internetwork  Sequence number facilitates ordering of packets REF: Cerf, V., and R. Kahn, "A Protocol for Packet Network Intercommunication", IEEE Transactions on Communications, Vol. COM-22, No. 5, pp 637-648, May 197411 © 2012 Persistent Systems Ltd
  12. 12. Foundation for TCP & IP Protocols - II  Process header (Port) – identify the end process that consumes the information  Retransmissions and Duplicate detection – addresses packet loss  Flow Control – to limit the number of un-acknowledged packets  Associations between two end processes (“connection”)  Mechanism to set up & release the association  3-way handshake, TCP State machine REF: Cerf, V., and R. Kahn, "A Protocol for Packet Network Intercommunication", IEEE Transactions on Communications, Vol. COM-22, No. 5, pp 637-648, May 197412 © 2012 Persistent Systems Ltd
  13. 13. ARPANET13 © 2012 Persistent Systems Ltd
  14. 14. TCP/IP Layered Architecture ModelEnd Application Application toend Transport Transport Network Network Network NetworkHop by Link Link Link Link Link Linkhop Physical Physical Physical Host Router Router Host14 © 2012 Persistent Systems Ltd
  15. 15. www.persistentsys.com Network Layer© 2012 Persistent Systems Ltd
  16. 16. IP : Protocol of choice for Network Layer  Packet-switched datagram network TCP UDP  IP is the glue (network layer overlay)  Hourglass architecture IP  all hosts and routers run IP Satellite  Stateless architecture  no flow state maintained in the Ethernet ATM network16 © 2012 Persistent Systems Ltd
  17. 17. IP Network Design Philosophy  Keep the network simple  Simple network devices, intelligent end-systems  Robust and scalable infrastructure  IP Networks offer Best-effort service today  No service guarantees or predictability  Connectionless, datagram model  Each IP packet carries sufficient information for its routing  Hop-by-hop routing – based on destination IP address only  Packets belonging to the same session could be routed differently  Out of sequence packet delivery  Network is application-agnostic – by design Intelligent end-points, “dumb” network model17 © 2012 Persistent Systems Ltd
  18. 18. IP: Minimalist Approach  Dumb network  IP provides minimal functionalities to support connectivity  Addressing, Forwarding, Routing  Smart end system  Transport layer or application performs more sophisticated functionalities  Flow control, Congestion control, Error correction/recovery  Advantages  Accommodate heterogeneous technologies (Ethernet, modem, satellite, wireless)  Support diverse applications (Email, Telnet, FTP, Usenet)  Decentralized network administration18 © 2012 Persistent Systems Ltd
  19. 19. Packet Switching Courtesy: William Stallings19 © 2012 Persistent Systems Ltd
  20. 20. Circuit Switching Courtesy: William Stallings20 © 2012 Persistent Systems Ltd
  21. 21. www.persistentsys.com Transport Layer© 2012 Persistent Systems Ltd
  22. 22. User Datagram Protocol (UDP) – RFC768  UDP – unreliable, datagram-based protocol  Connectionless End-to-End Service  Datagrams may be lost OR delivered out-of-ordered  Error Detection through Checksum (Optional)  Minimal overheads – no state maintained  No Congestion control  Used by Audio/Video Streams, short-transactional applications22 © 2012 Persistent Systems Ltd
  23. 23. Transmission Control Protocol (TCP) – RFC791  Designed to provide Reliable process-to-process communication service in a multi-network environment  Underlying network unreliable, may deliver bytes out-of-order  Fragmentation handled at the Network Layer  Connection-Oriented: Reliable, Ordered, Stream-based, flow and congestion controlled, bi-directional  Process Association (State) : combination of IP address and Port  Maintained only at the end hosts, not in the network  Sequence number & Window size facilitate ordering and flow control23 © 2012 Persistent Systems Ltd
  24. 24. Evolution of TCP 1984 1975 Nagel’s algorithm Three-way handshake to reduce overhead 1987 Raymond Tomlinson of small packets; Karn’s algorithm 1990 In SIGCOMM 75 predicts congestion to better estimate 4.3BSD Reno collapse round-trip time fast retransmit delayed ACK’s 1983 BSD Unix 4.2 1986 1988 1974 supports TCP/IP Congestion Van Jacobson’s TCP described by collapse algorithmsVint Cerf and Bob Kahn observed congestion avoidance In IEEE Trans Comm 1982 and congestion control TCP & IP (most implemented in RFC 793 & 791 4.3BSD Tahoe) 1975 1980 1985 1990 Courtesy: Shiv Kalyanaraman24 © 2012 Persistent Systems Ltd
  25. 25. TCP Through the 1990s 1994 1996 T/TCP SACK TCP (Braden) (Floyd et al) Transaction Selective TCP Acknowledgement 1993 1994 1996 1996 TCP Vegas ECN TCP Hoe FACK TCP (Brakmo et al) (Floyd) Improving TCP (Mathis et al) real congestion Explicit startup extension to SACK avoidance Congestion Notification 1993 1994 1996 Courtesy: Shiv Kalyanaraman25 © 2012 Persistent Systems Ltd
  26. 26. TCP Variants :  TCP-Tahoe:  implements the slow start, congestion avoidance, and fast retransmit algorithms  TCP-Reno:  implements the slow start, congestion avoidance, fast retransmit, and fast recovery algorithms  Among other implementations are Vegas, NewReno (the most commonly implemented on webservers today, according to a survey) and SACK TCP.26 © 2012 Persistent Systems Ltd
  27. 27. www.persistentsys.com INTERNET 2.0 Internet goes Commercial© 2012 Persistent Systems Ltd
  28. 28. Key Events in early 90s  Tim-Berners Lee proposed the idea for the World Wide Web  Mosaic – first graphical web browser launched in 1993  First commercial dial-up ISP started its service  Bandwidth doubling every six months  Push for Multimedia applications  Move towards Network Unification28 © 2012 Persistent Systems Ltd
  29. 29. Some observations Demand for broadband access and growth of bandwidth intensive apps fueling each other Applications demanding more from the underlying network  New applications – VoIP, streaming media  Stringent and often, inflexible requirements  “One-size fits-all” doesn’t work any more BROADBAND ACCESS “Dumb network” model may have reached its limits BANDWIDTH- INTENSIVE APPS Networks must provide a more predictable service29 © 2012 Persistent Systems Ltd
  30. 30. Growth of the Internet Copyright: http://www.zakon.org/robert/internet/timeline/30 Used with Permission © 2012 Persistent Systems Ltd
  31. 31. Growth of the Internet Copyright: http://www.zakon.org/robert/internet/timeline/31 Used with Permission © 2012 Persistent Systems Ltd
  32. 32. Applications: network requirements High Streaming Interactive Video Video Conferencing E-mail with Attachments Voice Requirements Internet/ Bandwidth intranet E-commerce Text ERP e-mail Terminal Mode Transactions Low Low Latency Sensitivity High32 © 2012 Persistent Systems Ltd
  33. 33. Evolution of Multi Service Networks  As Internet Usage increased, an evolved Next Generation Network (NGN) architecture became important  Characteristics of the NGN  One common network capable of handling data, voice and video communications  Packet-Switched Network -- “Data friendly” transport and switching infrastructure  Flexible services control elements to enable voice communications and support data and QoS in the future  Voice parity with the PSTN in terms of features and quality Source: http://tmdenton.com/pub/bellheads.pdf33 © 2012 Persistent Systems Ltd
  34. 34. www.persistentsys.com BellHeads vs NetHeads© 2012 Persistent Systems Ltd
  35. 35. Ideological Differences BellHeads NetHeadsCircuit-switched Telco background IP-based Internet backgroundAlign with Formal ITU Standards Align with Open IETF StandardsClosed Communities Open and Free CommunityBelieve in Guaranteed QoS Believe in Best-Effort ServicesExpect to get Paid for delivering service Expect services to be Cheap/FreeVoice: Per-minute charging with Voice: Just another App on the Packetsettlement between carriers switched network and is FREEDumb end-points, Smart Networks Dumb networks, Smart end-pointsWish to Control the Future of the Watch the Network Evolve organicallyNetworkPrefer Strong Regulatory Environment Open and Unregulated Playing Field35 © 2012 Persistent Systems Ltd
  36. 36. www.persistentsys.com Asynchronous Transfer Mode (ATM) Networks BellHead view of NGN© 2012 Persistent Systems Ltd
  37. 37. Bellheads view of NGN – ATM Networks  Packet switched network, but connection-oriented  Fixed size (53-byte) packets called “CELLS”  Path setup from source to destination before data transfer (“connection”)  All Cells of a connection traverse the same path  In the network, cells are “switched” based on the fixed header (VPI/VCI)  Using Admission Control policies, network can guarantee QoS for various applications37  Could support extremely high speeds (OC-192 or ~10Gbps) © 2012 Persistent Systems Ltd
  38. 38. ATM Everywhere38 © 2012 Persistent Systems Ltd
  39. 39. www.persistentsys.com Challenge for the Netheads© 2012 Persistent Systems Ltd
  40. 40. Per-packet processing in an IP Router 1. Accept packet arriving on an incoming link. 2. Lookup packet destination address in the forwarding table, to identify outgoing port(s) – Longest Prefix Match 3. Manipulate packet header: e.g., decrement TTL, update header checksum. 4. Send (switch) packet to the outgoing port(s). 5. Classify and buffer packet in the queue. 6. Transmit packet onto outgoing link. Courtesy: Shiv Kalyanaraman40 © 2012 Persistent Systems Ltd
  41. 41. Lookup Rates Required Optical Line Rate 40 Byte Pkts Lookup Interface (Gbps) (Mpps) Rates (ns) OC-12 0.622 1.94 515 OC-48 2.5 7.81 128 OC-192 10.0 31.25 33 OC-768 40.0 125 841 © 2012 Persistent Systems Ltd
  42. 42. Routing Table Size Source: Geoff Huston, Internet Protocol Journal, Vol 4, No. 142 © 2012 Persistent Systems Ltd
  43. 43. Router Performance Source: Ipsilon Networks43 © 2012 Persistent Systems Ltd
  44. 44. www.persistentsys.com Break-through for the Netheads © 2012 Persistent Systems Ltd
  45. 45. Routing vs Switching  Routing – based on address lookup and longest prefix match  Search and compare operation  Complexity : O(log2 N)  Switching – based on a circuit number (pre-set)  Indexing operation  Complexity : O(1)  Extremely well-suited for High-speed Networks with Large Address Spaces45 © 2012 Persistent Systems Ltd
  46. 46. 1996: Ipsilon’s IP Switching Concept Hybrid: IP routing (control plane) + ATM switching (data plane) Courtesy: Shiv Kalyanaraman46 © 2012 Persistent Systems Ltd
  47. 47. Ipsilon’s Solution Source: Ipsilon Networks47 © 2012 Persistent Systems Ltd
  48. 48. Ipsilon’s IP Switching Courtesy: Shiv Kalyanaraman48 © 2012 Persistent Systems Ltd
  49. 49. TCP/UDP Flow Statistics Source: Ipsilon Networks49 © 2012 Persistent Systems Ltd
  50. 50. MPLS: Best of Both Worlds PACKET CIRCUIT HYBRID SWITCHING ROUTING IP MPLS ATM TDM +IP Courtesy: Shiv Kalyanaraman50 © 2012 Persistent Systems Ltd
  51. 51. www.persistentsys.com Basics of MultiProtocol Label Switching (MPLS)© 2012 Persistent Systems Ltd
  52. 52. MPLS – Multiprotocol Label Switching  Introduces a new fixed-length header (label) for the IP packet payload  MPLS is considered Layer 2.5  Separates forwarding information (label) from IP header  Easy to implement this in hardware  Routing at the edge, switching at the core  MPLS label introduced at the ingress edge  Core routers use these labels to switch packets  Label removed at the egress edge router  Pre-defined paths for switching MPLS packets  Offline path creation – eliminates path computation overheads  MPLS header supports CoS markings52 © 2012 Persistent Systems Ltd
  53. 53. MPLS Header Label (20-bits) CoS S TTL L2 Header MPLS Header IP Packet 32-bits  Fields  Label  Experimental (CoS)  Stacking bit  Time to live  IP packet is encapsulated at an Entry into MPLS domain  IP packet is de-encapsulated at exit from MPLS domain53 © 2012 Persistent Systems Ltd
  54. 54. MPLS – Main Ideas  Separate forwarding information (label) from the content of IP header  Single forwarding paradigm (label swapping) - multiple routing paradigms  Multiple link-specific realizations of the label swapping forwarding paradigm  Flexibility of forming Forwarding Equivalence Classes (FECs)  Forwarding hierarchy via label stacking54 © 2012 Persistent Systems Ltd
  55. 55. MPLS Terminology Connection Table In Out Label IP 25 (port, label) (port, label) Operation Port 1 Port 2 (1, 22) (2, 17) Swap (1, 24) (3, 17) Swap IP 19 (1, 25) (4, 19) Swap Port 3 Port 4 (2, 23) (3, 12) Swap  Label Swapping  Connection table maintains mappings  Exact match lookup  Input (port, label) determines:  Label operation  Output (port, label)  Same forwarding algorithm used in Frame Relay and ATM Courtesy: Rahul Aggarwal55 © 2012 Persistent Systems Ltd
  56. 56. MPLS Terminology Egress LSR Ingress New York LSR Transit San LSR Transit Francisco LSR LSP  Ingress LSR (“head-end LSR”)  Examines inbound IP packets and assigns them to an FEC  Generates MPLS header and assigns initial label  Transit LSR  Forwards MPLS packets using label swapping  Egress LSR (“tail-end LSR”)56  Removes the MPLS header Courtesy: Rahul Aggarwal © 2012 Persistent Systems Ltd
  57. 57. MPLS Forwarding Model Source Egress Ingress LSR Paris LSR Rome  Ingress LSR determines FEC and assigns a label  Forwards Paris traffic on the Green LSP  Forwards Rome traffic on the Blue LSP  Traffic is label swapped at each transit LSR  Egress LSR  Removes MPLS header  Forwards packet based on destination address Courtesy: Rahul Aggarwal57 © 2012 Persistent Systems Ltd
  58. 58. MPLS Forwarding vs. IP Routing Source Destination IP Routing Domain Examine IP header Examine IP header Examine IP header Examine IP header Assign to FEC Assign to FEC Assign to FEC Assign to FEC Forward Forward Forward Forward Ingress Egress Source Destination LSR MPLS Domain LSR Examine IP header Examine IP header Assign to FEC Label swap Label swap Assign to FEC Forward Forward Forward Forward Courtesy: Rahul Aggarwal58 © 2012 Persistent Systems Ltd
  59. 59. MPLS Forwarding Example MPLS Table In Out 134.5.6.1 (2, 84) (6, 0) 134.5.1.5 2 6 Egress Routing Table Destination Next Hop 200.3.2.7 2 134.5/16 134.5.6.1 3 200.3.2/24 200.3.2.1 Ingress Routing Table 1 2 3 5 Destination Next Hop 200.3.2.7 134.5/16 (2, 84) 200.3.2/24 (3, 99) MPLS Table MPLS Table 200.3.2.1 200.3.2.7 In Out In Out (1, 99) (2, 56) (3, 56) (5, 0) Courtesy: Rahul Aggarwal59 © 2012 Persistent Systems Ltd
  60. 60. MPLS - Summary  MPLS forwarding algorithm is simpler than IP forwarding algorithm  Fixed size header vs variable sized header  Enables more functionality than could be provided with the IP forwarding algorithm  Eg. All packets traverse the same path through the domain  MPLS is an architectural shift  Enables many applications; difficult to foresee all of them  Most Service Providers today are moving towards MPLS deployment  Reduce cost, simplify operations, introduce high-value services  MPLS is also evolving  ER-MPLS, MPLS-TE etc.60 © 2012 Persistent Systems Ltd
  61. 61. www.persistentsys.com INTERNET 3.0 End of Network-Centric viewpoint© 2012 Persistent Systems Ltd
  62. 62. Some challenges with today’s Internet  Support for Mobility with TCP/IP not efficient  Security issues – viruses, spams, bots, DDOS attacks, hacks  Internet was designed with “friendly” users in mind  Multi-homing not well supported by TCP/IP  Change in IP Interface results in service disruption  Applications are designed to work well *only* if round-trip delays are small  TCP/IP expects most parts of the network to be interconnected  Routing protocols are becoming complex Courtesy: Raj Jain62  Routers are becoming expensive © 2012 Persistent Systems Ltd
  63. 63. Challenges….  Network-centric (“Where”) approach not optimal for various applications  People-centric – “Who”  Content-centric – “What”  IP Address correlates Identity and Location  This may neither be necessary nor desirable Courtesy: Raj Jain63 © 2012 Persistent Systems Ltd
  64. 64. Future Research  Delay Tolerant Network Architecture  Content-Centric Networks  Software Defined Network (SDN)  Network Virtualization paradigm64 © 2012 Persistent Systems Ltd
  65. 65. www.persistentsys.com Delay Tolerant Network© 2012 Persistent Systems Ltd
  66. 66. Delay Tolerant Networks (DTN)  DTNs Characterized by  Intermittent Connectivity  Extremely Long Delays  Asymmetric Data Rates  High Error Rates  Addressed using a Store-and-Forward Message Switching paradigm  IETF RFC 483866 © 2012 Persistent Systems Ltd
  67. 67. Delay Tolerant Network – Overlay Arch Source: http://www.cs.rice.edu/~scrosby/TA/comp620-s05/papers/F03.pdf67 © 2012 Persistent Systems Ltd
  68. 68. www.persistentsys.com Content Centric Network© 2012 Persistent Systems Ltd
  69. 69. Content Centric Networks69 © 2012 Persistent Systems Ltd
  70. 70. Content Centric Networks  Strategy – Figuring out the best path to deliver the content  Dynamic optimization  Security – Ensure content access only to authorized users  Interest Packet – used to request a specific content  Data Packet – contains the specific content  Mechanisms to forward an Interest packet towards available content store70 © 2012 Persistent Systems Ltd
  71. 71. www.persistentsys.com Software Defined Network© 2012 Persistent Systems Ltd
  72. 72. SDN Architecture App App App App Open API Network Operating System Open Interface to Hardware (OpenFlow) Openflow Openflow Firmware Firmware Packet-Forwarding Packet-Forwarding Hardware Hardware Openflow Openflow Firmware Firmware Packet-Forwarding Packet-Forwarding Hardware Hardware Courtesy: Matt Davy72 © 2012 Persistent Systems Ltd
  73. 73. Analogy with Computer Industry Computer Industry Network Industry Apps Apps Apps Apps Apps Apps Network Windows Linux FreeBSD NOX Beacon OS Virtualization Virtualization Openflow x86 Courtesy: Matt Davy73 © 2012 Persistent Systems Ltd
  74. 74. Software Defined Network74 © 2012 Persistent Systems Ltd
  75. 75. Does this look familiar?75 © 2012 Persistent Systems Ltd
  76. 76. www.persistentsys.com THANK YOU Email: venki@persistent.co.in© 2012 Persistent Systems Ltd
  77. 77. References 1. Prof Raj Jain’s home page - http://www.cse.wustl.edu/~jain/ 2. Dr Shivkumar Kalyanaraman’s lectures - http://www.ecse.rpi.edu/Homepages/koushik/shivkuma- teaching/video_index.html 3. Hobbes’ Internet Timeline - http://www.zakon.org/robert/internet/timeline/ 4. ACM Turing Award Video Lecture of Dr Cerf & Dr Kahn - http://amturing.acm.org/vp/cerf_1083211.cfm 5. Vint Cerf & Bob Kahn’s seminal paper on Protocol for Packet Network Intercommunication http://www.cs.princeton.edu/courses/archive/fall06/cos561/papers/cerf74.pdf 6. Relevant RFCs from IETF - www.ietf.org77 © 2012 Persistent Systems Ltd

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