11-01-K.Steenhaut & J.Tiberghien - VUB 1 Telecommunications Concepts Chapter 4.2 IPv4 and Other Networks

11-01-K.Steenhaut & J.Tiberghien - VUB 2 Contents Transmitting IP datagrams IP over Local Area Networks IP over Wide Area Networks –IP over leased lines –IP over circuit switched networks –IP over packet switched networks »IP over X25 »IP over Frame Relay »IP over ATM »IP and Quality of Service –MPLS Conclusions

11-01-K.Steenhaut & J.Tiberghien - VUB 3 Contents Transmitting IP datagrams IP over Local Area Networks IP over Wide Area Networks –IP over leased lines –IP over circuit switched networks –IP over packet switched networks »IP over X25 »IP over Frame Relay »IP over ATM »IP and Quality of Service –MPLS Conclusions

11-01-K.Steenhaut & J.Tiberghien - VUB 4 The Internet Sublayer IP approach Application 1Application 2Application 3 TCP Internet Protocol any network UDP

11-01-K.Steenhaut & J.Tiberghien - VUB 5 Transmitting IP Datagrams IP router IP router Underlying Network Underlying Network IP Datagram Underlying Network Frame

11-01-K.Steenhaut & J.Tiberghien - VUB 6 Contents Transmitting IP datagrams IP over Local Area Networks IP over Wide Area Networks –IP over leased lines –IP over circuit switched networks –IP over packet switched networks »IP over X25 »IP over Frame Relay »IP over ATM »IP and Quality of Service –MPLS Conclusions

11-01-K.Steenhaut & J.Tiberghien - VUB 7 IP over Ethernet Application 1Application 2Application 3 TCP Internet Protocol Ethernet UDP

11-01-K.Steenhaut & J.Tiberghien - VUB 8 Address Resolution Protocol Problem : –Mapping of IP and Ethernet addresses Solution : –ARP entity broadcasts IP address over Ethernet –All hosts compare broadcasted IP address with their own (software defined) IP address –Identified host answers the ARP broadcast. –IP datagrams for resolved address are encapsulated in Ethernet frame with Ethernet destination address.

11-01-K.Steenhaut & J.Tiberghien - VUB 9 IP over IEEE 802 LANs 4 3 2b IP addresses need to be translated into LAN addresses 2a cls

11-01-K.Steenhaut & J.Tiberghien - VUB 10 IP over traditional LANs IP addresses need to be translated into LAN addresses 2a

11-01-K.Steenhaut & J.Tiberghien - VUB 11 Reverse Address Resolution Protocol Problem : –Diskless workstations can not keep their (software defined) IP address. Solution : –A configuration server keeps mapping between IP addresses and corresponding Ethernet addresses. –At boot time a diskless station broadcasts a RARP frame. –Configuration server reads source Ethernet address in RARP frame and answers with corresponding IP address.

11-01-K.Steenhaut & J.Tiberghien - VUB 12 Contents Transmitting IP datagrams IP over Local Area Networks IP over Wide Area Networks –IP over leased lines –IP over circuit switched networks –IP over packet switched networks »IP over X25 »IP over Frame Relay »IP over ATM »IP and Quality of Service –MPLS Conclusions

11-01-K.Steenhaut & J.Tiberghien - VUB 13 Directly linked Routers

11-01-K.Steenhaut & J.Tiberghien - VUB 14 General Purpose SDH Networks PABX

11-01-K.Steenhaut & J.Tiberghien - VUB 15 Contents Transmitting IP datagrams IP over Local Area Networks IP over Wide Area Networks –IP over leased lines –IP over circuit switched networks –IP over packet switched networks »IP over X25 »IP over Frame Relay »IP over ATM »IP and Quality of Service –MPLS Conclusions

11-01-K.Steenhaut & J.Tiberghien - VUB 16 IP Networks Router

11-01-K.Steenhaut & J.Tiberghien - VUB 17 Serial Line Internet Protocol Designed in 1984 by Rick Adams (RFC 1055) For temporary IP links Data Link : –IP datagrams encapsulated in SLIP frames –Frame delimited by unique character ( ) –Character stuffing within the frame –No error detection (nor correction !) Network Layer : no layer 3 functions Many slightly different versions (RFC 1144) Essentially obsolete !

11-01-K.Steenhaut & J.Tiberghien - VUB 18 Point to Point Protocol Designed by the IETF (RFC 1661,RFC 1662,RFC 1663) For temporary links (various network protocols) Data Link : similar to HDLC or 802.2, but with bytes –Payload encapsulated in P frames –Frame delimited by flag ( ) –Character stuffing within the frame –Optional error correction with sliding window Network Layer : support for different protocols –Connection management, with authentication –Network protocol identifier field

11-01-K.Steenhaut & J.Tiberghien - VUB 19 Point to Point Protocol Multiple protocols over PPP Various physical layers under PPP TCP IP PPP UDP IPX ? Application, Transport & Network layers Physical layer PSTN ISDN GSM Leased Lines ADSL ?

11-01-K.Steenhaut & J.Tiberghien - VUB 20 P P P Advantages over SLIP CRC on every frame for error detection A link control protocol to: –establish connection –negotiate options –close connection Specific network control protocols –e.g. dynamic IP address assignment –e.g. TCP/IP header compression

11-01-K.Steenhaut & J.Tiberghien - VUB 21 IP over ISDN Usage : –Temporary interconnections –Back-up for leased lines –Additional capacity for overloaded leased lines Main problem : IP : Connectionless >< ISDN : Connection oriented Solutions : –One call per datagram (fast connection) –Keep connection for entire billing units –Keep connection during work-hours

11-01-K.Steenhaut & J.Tiberghien - VUB 22 Contents Transmitting IP datagrams IP over Local Area Networks IP over Wide Area Networks –IP over leased lines –IP over circuit switched networks –IP over packet switched networks »IP over X25 »IP over Frame Relay »IP over ATM »IP and Quality of Service –MPLS Conclusions

11-01-K.Steenhaut & J.Tiberghien - VUB 23 IP over X X25 IP datagramVCN X25 overhead IP addresses need to be translated into X25 addresses 33

11-01-K.Steenhaut & J.Tiberghien - VUB 24 IP over X25 Fast select call : best match between IP and X25 Virtual circuit between source and destination routers –Switched : opened and closed when ? –Permanent : analog to leased line, preferred solution Address resolution : IP address need to be translated into –X25 address for fast select call or for opening circuit –VC number for forwarding packet(s)

11-01-K.Steenhaut & J.Tiberghien - VUB 25 Contents Transmitting IP datagrams IP over Local Area Networks IP over Wide Area Networks –IP over leased lines –IP over circuit switched networks –IP over packet switched networks »IP over X25 »IP over Frame Relay »IP over ATM »IP and Quality of Service –MPLS Conclusions

11-01-K.Steenhaut & J.Tiberghien - VUB 26 IP over Frame Relay FR IP datagramVCNFR overhead IP addresses need to be translated into PVC numbers

11-01-K.Steenhaut & J.Tiberghien - VUB 27 IP over Frame Relay IP addresses need to be translated into Permanent Virtual Circuit Numbers. Assigning different application flows to PVC’s with different CIRs can enforce QOS criteria Passing the Congestion Notification bits to the transport layer could be useful but requires special IP and TCP/UDP implementations

11-01-K.Steenhaut & J.Tiberghien - VUB 28 Contents Transmitting IP datagrams IP over Local Area Networks IP over Wide Area Networks –IP over leased lines –IP over circuit switched networks –IP over packet switched networks »IP over X25 »IP over Frame Relay »IP over ATM »IP and Quality of Service –MPLS Conclusions

11-01-K.Steenhaut & J.Tiberghien - VUB 29 IP over ATM Application 1Application 2Application 3 TCP-UDP IP any network Application 1Application 2Application 3 ATM aal ATM aal

11-01-K.Steenhaut & J.Tiberghien - VUB 30 IP over ATM, but... IP is connectionless, –each packet contains destination and origin addresses. –Broadcasting of messages frequently required ATM is connection oriented, –Virtual channels need to be established (and evt. closed) –each cell contains a Virtual Channel number –ATM addresses are unrelated to IP addresses –No broadcasting Connection management required. Address Translation mechanism required. Broadcast server required

11-01-K.Steenhaut & J.Tiberghien - VUB 31 IP over ATM ATM IP datagramvcnATM/AAL overhead AAL

11-01-K.Steenhaut & J.Tiberghien - VUB 32 ATM Adaptation Layer Data encapsulation padAAL padAAL Higher layer PDU ATM header

11-01-K.Steenhaut & J.Tiberghien - VUB 33 IP over ATM, solutions 1. Classical IP over ATM –Initially proposed by IETF –ARP server translates the addresses –All addresses stored on one ARP server define one subnet –Different subnets have to communicate via routers –Broadcasts have to be generated by IP entity –Requires modified IP implementation

11-01-K.Steenhaut & J.Tiberghien - VUB 34 Classical IP over ATM Router ARP Server ATM Network

11-01-K.Steenhaut & J.Tiberghien - VUB 35 LAN emulation Application 1Application 2Application 3 TCP-UDP IP any network ATM LLC Application 1Application 2Application 3 ???

11-01-K.Steenhaut & J.Tiberghien - VUB 36 IP over ATM, solutions 2. LAN emulation –Proposed by ATM Forum –Ethernet MAC emulation –Two or three servers: »Lan Emulation Server registers and translates MAC addresses »Broadcast and Unknown Server distributes the broadcast and multicast packets »Lan Emulation Configuration Server keeps ATM addresses of Lan Emulation Servers –No modifications to IP

11-01-K.Steenhaut & J.Tiberghien - VUB 37 LAN Emulation Router LES,BUS,LECS Servers ATM Network Bridge

11-01-K.Steenhaut & J.Tiberghien - VUB 38 Contents Transmitting IP datagrams IP over Local Area Networks IP over Wide Area Networks –IP over leased lines –IP over circuit switched networks –IP over packet switched networks »IP over X25 »IP over Frame Relay »IP over ATM »IP and Quality of Service –MPLS Conclusions

11-01-K.Steenhaut & J.Tiberghien - VUB 39 IP and QOS Facts : –Connectionless IP is unable to guarantee QOS –Multi-media applications require QOS Solutions : –Provide more than enough capacity between routers –Force, for specific flows, special routes. –Use QOS resources of underlying network »Traditional routing algorithms do not allow differentiation between datagrams with same destination. »Additional intermediate protocols needed

11-01-K.Steenhaut & J.Tiberghien - VUB 40 IP and QOS Facts : –Connectionless IP is unable to guarantee QOS –Multi-media applications require QOS Solutions : –Provide more than enough capacity between routers –Force, for specific flows, special routes. –Use QOS resources of underlying network »Traditional routing algorithms do not allow differentiation between datagrams with same destination. »Additional intermediate protocols needed

11-01-K.Steenhaut & J.Tiberghien - VUB 41 IP and QOS Facts : –Connectionless IP is unable to guarantee QOS –Multi-media applications require QOS Solutions : –Provide more than enough capacity between routers –Force, for specific flows, special routes. –Use QOS resources of underlying network »Traditional routing algorithms do not allow differentiation between datagrams with same destination. »Additional intermediate protocols needed

11-01-K.Steenhaut & J.Tiberghien - VUB 42 IP v 4 Header (2) Source IP Address Destination IP Address OptionsPadding Header Checksum IdentFrag.Offset Total Length TTL Typ.Ser. Fl. Proto VerLen Typ.Serv.:Precedence (0 = normal, 7 = control) D = Short delay wanted (best effort) T = High throughput wanted (best effort) R = High reliability wanted (best effort)

11-01-K.Steenhaut & J.Tiberghien - VUB 43 IP v 4 Options Class 0 Length Option –1 : End of option list 1 –2 : Security and handling restrictions11 –3 : Loose Source Routingvar –7 : Record routevar –9 : Strict Source Routingvar Class 2 Option –4 : Internet timestampvar

11-01-K.Steenhaut & J.Tiberghien - VUB 44 QOS Routing Ser = D Ser = T Ser = R

11-01-K.Steenhaut & J.Tiberghien - VUB 45 IP and QOS Facts : –Connectionless IP is unable to guarantee QOS –Multi-media applications require QOS Solutions : –Provide more than enough capacity between routers –Force, for specific flows, special routes. –Use QOS resources of underlying network (ATM) »Traditional routing algorithms do not allow differentiation between datagrams with same destination. »Additional intermediate protocols needed

11-01-K.Steenhaut & J.Tiberghien - VUB 46 Multi Protocol Over ATM Single or initial frame ATM Network = MPOA server

11-01-K.Steenhaut & J.Tiberghien - VUB 47 Multi Protocol Over ATM Subsequent frames ATM Network = MPOA server

11-01-K.Steenhaut & J.Tiberghien - VUB 48 Contents Transmitting IP datagrams IP over Local Area Networks IP over Wide Area Networks –IP over leased lines –IP over circuit switched networks –IP over packet switched networks »IP over X25 »IP over Frame Relay »IP over ATM »IP and Quality of Service –MPLS Conclusions

11-01-K.Steenhaut & J.Tiberghien - VUB 49 Multi Protocol Label Switching = Ingres/Egres Router Any Network Add signaling protocol to network to allow establishment of virtual circuit for some data flows.

11-01-K.Steenhaut & J.Tiberghien - VUB 50 Multi Protocol Label Switching IP datagramlabel X25 overhead IP datagramlabelFR overhead IP datagramlabelATM overhead Optimizes IP address to VC number translation by explicitly identifying flows of datagrams with common QOS requirements. MPLS = attempt to standardize these labels (RFC Jan 2001)

11-01-K.Steenhaut & J.Tiberghien - VUB 51 IP v 6 Header Source IP Address Destination IP Address Payload Length Flow Label Next HdrHop Lim. VerPri Flow = connection oriented communication implemented through connectionless service Flow uniquely identified by source address flow label Avoids label field between layer 2 and 3 overhead Flow Label : enables MPLS in IP V6

11-01-K.Steenhaut & J.Tiberghien - VUB 52 Contents Transmitting IP datagrams IP over Local Area Networks IP over Wide Area Networks –IP over leased lines –IP over circuit switched networks –IP over packet switched networks »IP over X25 »IP over Frame Relay »IP over ATM »IP and Quality of Service –MPLS Conclusions

11-01-K.Steenhaut & J.Tiberghien - VUB 53 The Future ??? IP ATM SDH Application IP+MPLS ATM/FR SDH Application IP+MPLS ATM/FR SDH Application IP+MPLS ATM/FR SDH Application Optical Fibers + WDM IPv6 ATM/FR SDH Application