11 Polytechnic UniversityM. VeeraraghavanThree planes in networksProf. Malathi VeeraraghavanElec. & Comp. Engg. Dept/CATTPolytechnic [email protected] Polytechnic UniversityM. VeeraraghavanUser plane, control plane, and management plane• Management plane: consists of all the protocols needed to “configure” data tables for the operation of the network– For example, protocols for routing data dissemination (distributed or centralized)– Other functions: performance, fault mgmt., accounting, security• Control plane:– Connection control protocols• in CO networks, this includes connection setup at each switch (connections at the network layer)• in CL networks, this includes connection setup only at the endpoints (connections at the transport layer, if the TL protocol is reliable)– Call control protocols• User plane: protocols for the actual flow of data23 Polytechnic UniversityM. VeeraraghavanRouting protocol in all three types of networks - Phase 1Host AHost BIIVVIIIIIRouting protocolRouting protocolRouting protocolDest. Next hopIII-*IVDest. Next hopIII-*IIIDest. Next hopBBRouting tables• Routing protocols exchange topology/loading/reachability information• Routes to destinations are precomputed and stored in routing tables4 Polytechnic UniversityM. VeeraraghavanSignaling protocol for NL connection setup in a PS CO network - Phase 2• Connection setup consists of each switch on the path– Route lookup for next hop node to reach destination– CAC (Connection Admission Control) for buffer and BW– Writing the input/output label mapping tables and programming the schedulerHost AHost BIIVVIIIIIConnection setupConnection setupabcabcddcabINPort /LabelOUTPort/Labela/L1c/L2INPort /LabelOUTPort/Labela/L2c/L1INPort /LabelOUTPort/Labeld/L1b/L3Connection setup (B)ConnectionsetupVirtual circuit35 Polytechnic UniversityM. VeeraraghavanSignaling protocol for NL connection setup in a CS CO network - Phase 2• Connection setup consists of each switch on the path– Route lookup for next hop node to reach destination– CAC (Connection Admission Control) for BW (note: no buffers)– Writing the port/timeslot/λ mapping table Host AHost BIIVVIIIIIConnection setupConnection setupabcabcddcabINPort /TimeslotOUTPort/Timeslota/1c/2INPort /TimeslotOUTPort/Timeslota/2c/2INPort /TimeslotOUTPort/Timeslotd/2b/1Connection setup (B)ConnectionsetupCircuit6 Polytechnic UniversityM. VeeraraghavanUser-plane packet forwarding in a PS CO network - Phase 3• Labels are VPI/VCIs in ATM• Labels are translated from link-to-linkHost AHost BIIVVIIIIIabcabcddcabL2L1L1L3INPort /LabelOUTPort/Labela/L1c/L247 Polytechnic UniversityM. VeeraraghavanUser-plane actions in a circuit-switched network - Phase 3• Bits arriving at switch I on time slot 1 on port a are switched to time slot 2 of port cHost AHost BIIVVIIIIIabcabcddcab12121212OUTPort/TimeslotINPort /Timeslota/1c/28 Polytechnic UniversityM. VeeraraghavanUser-plane packet forwarding in a CL PS network - Phase 3 • Packet headers carry destination host address (unchanged as it passes hop by hop)• Each CL packet switch does a route lookup to determine the outgoing port/next hop nodeHost AHost BIIVVIIIIIabcabcddcabBBBB59 Polytechnic UniversityM. VeeraraghavanAddressing• Where are endpoint addresses used:– In CL PS networks, endpoint addresses are carried in packet headers– In CO networks, be it PS or CS, endpoint addresses are carried in connection setup messages10 Polytechnic UniversityM. VeeraraghavanSummarized addresses• What are summarized addresses?• Why summarize addresses?611 Polytechnic UniversityM. VeeraraghavanSummarized addresses• What are summarized addresses?– An address that represents a group of endpoint addresses– e.g., all 212 numbers, 128.238 IP addresses• Why summarize addresses?– Reduces routing table sizes – hold one entry for a summarized address instead of a large number of individual addresses– Reduces routing message lengths that convey reachability information12 Polytechnic UniversityM. VeeraraghavanExamples of signaling protocols• SS7 (Signaling System No. 7) network (with its SS7 protocol stack) carries signaling messages to set up and release circuits in a telephone network713 Polytechnic UniversityM. VeeraraghavanExamples of routing protocols•In the Internet:– Link-state routing protocols, such as Open Path Shortest First (OSPF)– Distance-vector based routing protocols, such as Routing Information Protocol (RIP)• In telephone networks:– Real-Time Network Routing (RTNR)14 Polytechnic UniversityM. VeeraraghavanExamples of addressing schemes• Internet– 4-byte IP addresses• Telephone networks– 8-byte E.164 address (telephone number)• ATM networks– 20-byte ATM End System Address