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Three planes in networks. Prof. Malathi Veeraraghavan Elec. & Comp. Engg. Dept/CATT Polytechnic University mv@poly.edu. User plane, control plane, and management plane. Management plane: consists of all the protocols needed to “configure” data tables for the operation of the network
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Three planes in networks Prof. Malathi Veeraraghavan Elec. & Comp. Engg. Dept/CATT Polytechnic University mv@poly.edu
User 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 data
Routing protocol Routing protocol Routing protocol Dest. Dest. Dest. Next hop Next hop Next hop III-* III-* B III IV B Routing tables Routing protocol in all three types of networks - Phase 1 II III Host B I Host A V IV • Routing protocols exchange topology/loading/reachability information • Routes to destinations are precomputed and stored in routing tables
Connection setup (B) b a a Connection setup Connection setup b c b d c c a Connection setup d IN Port /Label IN Port /Label IN Port /Label OUT Port/Label OUT Port/Label OUT Port/Label d/L1 a/L1 a/L2 b/L3 c/L2 c/L1 Virtual circuit Signaling 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 scheduler II III I Host A Host B V IV
Connection setup (B) b a a Connection setup Connection setup b c b d c c a Connection setup d IN Port /Timeslot OUT Port/Timeslot IN Port /Timeslot IN Port /Timeslot OUT Port/Timeslot OUT Port/Timeslot a/1 c/2 d/2 a/2 b/1 c/2 Circuit Signaling 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/l mapping table II III I Host A Host B V IV
IN Port /Label OUT Port/Label L3 L1 L1 L2 a/L1 c/L2 User-plane packet forwarding in a PS CO network - Phase 3 • Labels are VPI/VCIs in ATM • Labels are translated from link-to-link II b a a III I Host A b c Host B b d c c V IV a d
1 2 IN Port /Timeslot OUT Port/Timeslot a/1 c/2 1 1 2 2 1 2 User-plane actions in a circuit-switched network - Phase 3 II • Bits arriving at switch I on time slot 1 on port a are switched to time slot 2 of port c b a a III I Host A b c Host B b d c c V IV a d
B B B B User-plane packet forwarding in a CL PS network - Phase 3 II • 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 node b a a III I Host A b c Host B b d c c V IV a d
Addressing • 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 messages
Summarized addresses • What are summarized addresses? • Why summarize addresses?
Summarized 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 information
Examples 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 network
Examples 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)
Examples 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 (AESA)