Converged Networks. Networks

Transcription

1 Converged Networks Networks From Telecom to Datacom, Asynchronous Transfer Mode () From Datacom to Telecom, Multiprotocol Label Switching (MPLS) Further Convergence Evolving Networks OPTI 500, Spring 2011, Lecture 8, Converged Networks 1

2 Data Communication to Telecommunication Multiprotocol Label Switching IP Frame Relay IP MPLS Frame Relay MPLS standardization began in 1997 by the IETF MPLS uses a small, 20 byte label inserted between the Layer 3 (IP) packet header and the Layer 2 frame header MPLS provides A fast forwarding mechanism Support for connection-oriented switching Quality of service assurance for voice, video, and time critical data OPTI 500, Spring 2011, Lecture 8, Network Convergence 2

3 Data Communication to Telecommunication Multiprotocol Label Switching IP Frame Relay IP MPLS Frame Relay MPLS standardization began in 1997 by the IETF MPLS uses a small, 20 byte label inserted between the Layer 3 (IP) packet header and the Layer 2 frame header MPLS provides A fast forwarding mechanism Support for connection-oriented switching Quality of service assurance for voice, video, and time critical data OPTI 500, Spring 2011, Lecture 8, Network Convergence 3

4 Network Convergence Network convergence refers to the use of both datacom and telecom protocols and hardware in the same network. The motivation is to share resources and to combine the flexibility of datacom networks with the high capacity and Quality of Service assurance of telecom networks OPTI 500, Spring 2011, Lecture 8, Network Convergence 4

5 Protocol Stacks Application Multiprotocol Label Switching (MPLS) WDM Presentation Session Transport Network Data Link Physical HTTP, Telnet, FTP Transmission Control Protocol (TCP) User Datagram Protocol (UDP) Internet Protocol (IP) SONET, Ethernet, Frame Relay Asynchronous Transfer Mode () By the 1990 s Internet Protocol had become the most important data network protocol SONET had become the most important telecommunication protocol OPTI 500, Spring 2011, Lecture 8, Network Convergence 5

6 Standards Bodies International Telecommunications Union (ITU) Wavelength Division Multiplexing (WDM) Asynchronous Transfer Mode () Internet Engineering Task Force (IETF) TCP/IP Multiprotocol Label Switching (MPLS) OPTI 500, Spring 2011, Lecture 8, Network Convergence 6

7 Telecommunication to Data Communication Asynchronous Transfer Mode () over SONET SONET was standardized in the 1990 s by the ITU It is an ambitious approach to carrying a very wide range of services provides Quality of Service (QOS) guarantees, for voice, video, and critical data services, that IP does not networks are now widely deployed OPTI 500, Spring 2011, Lecture 8, Network Convergence 7

8 An Cell Includes a Virtual Channel Identifier for Virtual Circuit Switching Payload (48 bytes) Header (5 bytes) The relatively small 48 byte payload represents a compromise between requirements for: Fast switching to ensure quality of service Low overhead for more efficient use of bandwidth OPTI 500, Spring 2011, Lecture 8, Network Convergence 8

9 Virtual Circuit Switching (Connection Oriented Networks) Next path determined by packet header read at this node In Out 1 Next path determined by packet Header read at this node Networks with virtual circuit switching look like circuit switched networks, but the circuits are not hard wired OPTI 500, Spring 2011, Lecture 8, Network Convergence 9 1

10 Virtual Circuit Switching Virtual circuit switching mimics old-fashion circuit switching OPTI 500, Spring 2011, Lecture 8, Network Convergence 10

11 Network Classification by Switching Type Communication Networks Switched Networks Broadcast Networks Ethernet Circuit Switched Packet Switched SONET Connetion- Oriented, Frame Relay MPLS Connectionless IP, Ethernet OPTI 500, Spring 2011, Lecture 8, Network Convergence 11

12 Asynchronous Transfer Mode Reference Model Establishes virtual channels Resolves problems Transmits data Adapts data from higher layers for transmission across network Management Plane Control Plane User Plane Higher Layers Higher Layers Adaption Layer Layer Layer Management Plane Management Switching at network nodes Physical Layer Prepares data for transmission over SONET OPTI 500, Spring 2011, Lecture 8, Network Convergence 12

13 Stack Traversal Across an Network Computer A Computer B Higher Layers Higher Layers Adaptation Switch Switch Switch Switch Adaptation Physical Physical Phycial Physical Physical Physical Physical Transport Medium (Cable, Optical Fiber ) Network Node switching takes place at the layer OPTI 500, Spring 2011, Lecture 8, Network Convergence 13

14 Data Communication to Telecommunication Multiprotocol Label Switching IP Frame Relay IP MPLS Frame Relay MPLS standardization began in 1997 by the IETF MPLS uses a small, 20 byte label inserted between the Layer 3 (IP) packet header and the Layer 2 frame header MPLS provides A fast forwarding mechanism Support for connection-oriented switching Quality of service assurance for voice, video, and time critical data OPTI 500, Spring 2011, Lecture 8, Network Convergence 14

15 Motivation for Further Convergence Internet protocol dominates data transfer and was not able to displace it. IP over Frame Relay with MPLS does not provide the capacity of SONET and WDM OPTI 500, Spring 2011, Lecture 8, Network Convergence 15

16 A More Fully Converged Network IP MPLS SONET WDM The communication infrastructure has evolved so that complicated convergence schemes like this are widely used today People agree that simplification would be a good thing OPTI 500, Spring 2011, Lecture 8, Network Convergence 16

17 IP over WDM IP? WDM IP is here to stay So is WDM The question is how to most efficiently build networks that use both Real world solutions must take into account the current network infrastructure OPTI 500, Spring 2011, Lecture 8, Network Convergence 17