1. (C) All rights reserved by Professor Wen-Tsuen Chen1 ä Interior Gateway Routing Protocol í A Routing Protocol within an autonomous system (AS). í OSPF (Open Shortest Path First) RFC 1247 (Version 1), RFC 1583 (Version 2). ä Exterior Gateway Routing Protocol í A Routing Protocol between ASes. í BGP (Border Gateway Protocol) RFC 1654. Internet Routing Protocol

2. (C) All rights reserved by Professor Wen-Tsuen Chen2 OSPF Routing Protocol ä Support a variety of distance metrics, including physical distance, delay, etc. ä Support routing based on type of service. ä Load balancing: splitting the load over multiple lines. ä Support for hierarchical systems: dividing an AS into number areas.

3. (C) All rights reserved by Professor Wen-Tsuen Chen3 Graph representation in OSPF ä OSPF computes the shortest path from every router to every other router.

4. (C) All rights reserved by Professor Wen-Tsuen Chen4 AS as a hierarchical system ä An area is a network or a set of contiguous networks. ä Every AS has a backbone area, called area o. Internal Routers, Area Border Routers, Backbone Routers, AS boundary Routers

5. (C) All rights reserved by Professor Wen-Tsuen Chen5 ä Within an area, each router runs the same shortest path algorithm to calculate the shortest path to every other router in the area. ä Handle type of service routing with multiple graphs, one labeled with costs of the type of service. ä For routing within an AS, need intra-area and inter-area routers.

6. (C) All rights reserved by Professor Wen-Tsuen Chen6 ä OSPF uses link state routing algorithms: í A designated router in a LAN. Exchange information only with designated routers.

7. (C) All rights reserved by Professor Wen-Tsuen Chen7 BGP Routing Protocol ä BGP1 in 1989, current version BGP4 in 1993. ä BGP is fundamentally a distance vector protocol. ä Each BGP keeps track of the exact path used. ä After all the paths come in from the neighbors, the best can be determined. äSince each router keeps the exact routes used, the count-to-infinite problem can be easily solved. äBGPs uses TCP as its transport protocol (port 179). for reliable transmission.

8. (C) All rights reserved by Professor Wen-Tsuen Chen8 Internet Multicasting ä IP supports multicasting using class D addresses. ä Permanent addresses and temporary addresses. í Permanent addresses 224.0.0.1 all systems on a LAN 224.0.0.1 all systems on a LAN 224.0.0.2 all routers on a LAN 224.0.0.2 all routers on a LAN 224.0.0.5 all OSPF routers on a LAN 224.0.0.5 all OSPF routers on a LAN 224.0.0.6 all designated routers on a LAN 224.0.0.6 all designated routers on a LAN ä A multicast router uses the IGMP (Internet Group Management Protocol) to group hosts the groups their processes currently belong to. ä IGMP in RFC 1112. ä Multicast routing uses spanning trees.

9. (C) All rights reserved by Professor Wen-Tsuen Chen9 IP Mobility Support ä Each mobile host is able to use its home IP address anywhere. ä Home agent vs. foreign agent.

10. (C) All rights reserved by Professor Wen-Tsuen Chen10 IPv6 ä A modified combined version of Deering and Francis proposals. SIPP (Simple Internet Protocol Plus). ä RFC 1752 issued in Jan 1995,RFC 1883, 1884, 1886,1887,1809,… ä Longer addresses. ä Simplification of headers. ä Support for options. ä Security and authentication. ä Type of services.

11. (C) All rights reserved by Professor Wen-Tsuen Chen11 IPv6 Header

12. (C) All rights reserved by Professor Wen-Tsuen Chen12 ä Priority: 0~7 for transmissions possibly slowed down in case of congestion. 8~15 for real-time traffic. ä Flow label: for setting up a pseudo connection with particular properties and requirements. ä Payload length: information bytes following the 40 byte header. 64 K bytes maximum. ä Next header: specify which of the (currently six) extension headers, if any, follows the header. If the header is the last IP header, the Next header specifies the transport protocol handler. ä Hop limit: for limiting packet lifetime.

13. (C) All rights reserved by Professor Wen-Tsuen Chen13 IPv6 addresses

14. (C) All rights reserved by Professor Wen-Tsuen Chen14 ä No packet fragmentation í All IPv6 conformant hosts and router must support packets of 576 bytes. í The router that is unable to forward a large packet sends back an error message, to tell the host to fragment future packets. ä No header checksum. ä No IHL because IPv6 header has a fixed length.

15. (C) All rights reserved by Professor Wen-Tsuen Chen15 IPv6 Data Unit IPv6 Header Extension Header... Transport DU 40 octets 0 or more

16. (C) All rights reserved by Professor Wen-Tsuen Chen16 IPv6 Extension Headers

17. (C) All rights reserved by Professor Wen-Tsuen Chen17 ä The hop-by-hop header should be examined by all routers along the path. ä Jumbograms are large datagrams exceeding 65,536 bytes. Hop-by-Hop Extension Header

18. (C) All rights reserved by Professor Wen-Tsuen Chen18 Routing Extension Headers

19. (C) All rights reserved by Professor Wen-Tsuen Chen19 Routing Extension Headers (cont.) ä List one or more routers that must be visited. ä starts at 0 and is incremented as each address is visited. ä Next address starts at 0 and is incremented as each address is visited. ä tells whether each address must be visited directly after the one before it (strict source routing), or whether other routers may come in between (loose source routing). ä Bit map tells whether each address must be visited directly after the one before it (strict source routing), or whether other routers may come in between (loose source routing).

20. (C) All rights reserved by Professor Wen-Tsuen Chen20 ATM Layer in ATM networks ä Connection-oriented. ä No acknowledgements. ä Cells arriving destinations in order. ä Tow-level connection hierarchy.

21. (C) All rights reserved by Professor Wen-Tsuen Chen21 Payload Type

22. (C) All rights reserved by Professor Wen-Tsuen Chen22 ATM Cell Header

23. (C) All rights reserved by Professor Wen-Tsuen Chen23 Connection Setup/Release

24. (C) All rights reserved by Professor Wen-Tsuen Chen24

25. (C) All rights reserved by Professor Wen-Tsuen Chen25 ATM Routing To route on the VPI field except at the final hop.

26. (C) All rights reserved by Professor Wen-Tsuen Chen26

27. (C) All rights reserved by Professor Wen-Tsuen Chen27

28. (C) All rights reserved by Professor Wen-Tsuen Chen28 Quality of Service Categories

29. (C) All rights reserved by Professor Wen-Tsuen Chen29

30. (C) All rights reserved by Professor Wen-Tsuen Chen30 ä QoS Parameters: CLP, CTD, CDV í CBR: CDV, CTD, CLP í rt-VBR: CDV, CTD, CLP í nrt-VBR: CLP ä Traffic Parameters: í CBR: PCR, CDVT í rt-VBR: PCR, CDVT, SCR, MBS í nrt-VBR: PCR, CDVT, SCR, MBS í UBR: PCR, CDVT í ABR: PCR, CDVT, MCR where MBS is the maximum burst size.

31. (C) All rights reserved by Professor Wen-Tsuen Chen31

32. (C) All rights reserved by Professor Wen-Tsuen Chen32 Traffic contract ä A traffic contract specifies the negotiated characteristics of a connection. ä Traffic contract specification consists of í A connection traffic descriptor. í A set of QoS parameters for each direction of the connection. í The definition of a compliant. ä Connection traffic descriptor includes í A set of traffic parameter of the ATM source. í The CDVT. í The conformance definition that specifies the conforming cells of the connection.

33. (C) All rights reserved by Professor Wen-Tsuen Chen33 The Generic Cell Rate Algorithm (GCRA) ä GCRA (I, L) Where I: Increment Where I: Increment L: Limit L: Limit

34. (C) All rights reserved by Professor Wen-Tsuen Chen34

35. (C) All rights reserved by Professor Wen-Tsuen Chen35 Traffic Policing Cell t1t1 t1t1 t1t1 t1t1 t2 Maximal case Cell 2 arrives T sec after Cell 1 Slow sender. Cell 2 arrives > T sec after Cell 1 Fast sender. Cell 2 arrives up to L sec early Very fast sender. Cell 2 arrives prior to t 1 + T - L. Cell is nonconforming Cell 3 expected at t 1 + T Cell 3 expected at t 2 + T Cell 3 expected at t 2 + T Cell 3 expected at t 2 + 2T T

36. (C) All rights reserved by Professor Wen-Tsuen Chen36 Traffic Contract Conformance Definition ä Traffic Management specification,Version 4.0 ä CBR Service: í GCRA (1/PCR, CDVT) ä VBR Services í GCRA (1/PCR, CDVT) í GCRA (1/SCR, BT+CDVT), where BT = (MBS-1)(1/SCR-1/PCR) ä UBR Services î PCR ä ABR î DGCRA The ATM Forum, April 1996

37. (C) All rights reserved by Professor Wen-Tsuen Chen37 Congestion Control ä Admission Control with resource reservation. ä Rate-based Congestion Control for ABR traffic.  The sender has a current cell rate ACR (Actual Cell Rate), MCR  ACR  PCR. ä ACR is reduced, if congestion occurs. ä For each RM-cell, ER (Explicit Rate) is set by the source to a requested rate (such as PCR) and may be subsequently reduced by any network element in the path to a value that the element can sustain. ER is then used to limit the source ACR to a specific value.

38. (C) All rights reserved by Professor Wen-Tsuen Chen38 ATM LAN Emulation ä LES: LAN Emulation Server ä BUS: Broadcast/Unknown Server