Abstract
This chapter presents high-speed networking technologies and standards such as Asynchronous Transfer Mode (ATM), Fast Ethernet, 10 Gigabit Ethernet, Synchronous Optical Network (SONET), Resilient Packet Ring (RPR), Provider Backbone Transport (PBT), Provider Backbone Bridges (PBB), Transport - Multi Protocol Label Switching (T-MPLS) and Optical Transport Network (OTN). It considers the requirements imposed to high-speed networks by multimedia applications and analyses crucial issues of high-speed networking such as bandwidth problems, discarding policies and fast broadcast. Finally, the chapter discusses future trends in high-speed multimedia networking.
TopBackground
In the 1990s, many multimedia services were developed on a single network infrastructure, while many QoS mechanisms emerged in order to support real-time and interactive applications (Aurrecoechea et al., 1998). Giordano et al. (2003) describe the current evolution of QoS architectures, mechanisms and protocols in the Internet, as it is ongoing in the framework of the European Union funded research projects (AQUILA, CADENUS, TEQUILA) on premium Internet Protocol (IP) networks. Recently, an IP based global information infrastructure (GII) was established, which was increasingly based on fast packet switching technology interconnected by fibber optic cable. The IP joined previously disjoint networks, while the World Wide Web (Web) became the killer application that drove bandwidth demand. Today, customers access not only data in Web pages but images and streaming multimedia content using Web browsers.
High-speed networking research moved up the protocol stack to be more concerned with multimedia applications. In the late 1990s, we had the practical application of fast packet switching technology to IP routers, which became IP switches. This was caused by the failure of Asynchronous Transfer Mode (ATM) and the decreasing cost in hardware. This divergence of high-speed networking research into the application layer and switch design had the effect of fragmenting the discipline into other sub-disciplines of communications such as router/switch design and multimedia applications. Two forces resisted the global deployment of a connection-oriented network layer such as ATM.
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In the mid 1990s, the explosion of the Internet and Web entrenched TCP as the end-to-end protocol and IP as the single global network layer.
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The limitations of shared medium link protocols such as Ethernet and token ring were overcome by the evolution of Ethernet to a switched point-to-point link protocol with order-of-magnitude increases in data rate. This evolution additionally reduced the motivation for adoption of ATM using scalable Synchronous Optical Network (SONET) links to increase the bandwidth on network links.
The important characteristics of fast packet switching technologies began to be incorporated into the Internet. For example, IP switches based on the fast switch fabrics and protocol optimisations such as Multi Protocol Label Switching (MPLS) began to be established (Armitage, 2000).
Key Terms in this Chapter
Virtual path (VP): It is defined as a set of multiplexed circuits, which terminate at common end nodes such as switching nodes and network gateways.
Carrier Sense Multiple Access With Collision Detection CSMA/CD: It is a network control protocol in which a carrier-sensing scheme is used. In CSMA/CD, a transmitting data station that detects another signal while transmitting a frame, stops transmitting that frame, transmits a jam signal, and then waits for a random time interval (known as “backoff delay” and determined using the truncated binary exponential backoff algorithm) before trying to send that frame again.
Fibre Channel (FC): It is a gigabit-speed network technology used for storage networking. FC can run on both twisted pair copper wire and fiber-optic cables. Fiber always denotes an optical connection, whereas fibre is always the spelling used in “fibre channel” and denotes a physical connection, which may or may not be optical.
IEEE 802.1ag (Connectivity Fault Management): It specifies support for proactive alarming of service faults and assists with the detection, verification and isolation of connectivity failures.
Operations, Administration, and Maintenance (OAM): This is a general term used to describe the processes, activities, tools, standards, etc involved with operating, administering, and maintaining any networked computer system.
Bandwidth on Demand: It refers to data rate measured in bit/s (channel capacity or throughput-bandwidth consumption), which is required in order to transfer continuous media data (e.g. video).
Delay Variation (or Delay Jitter): It is a term used for the variation of end-to-end delay from one packet to the next packet within the same packet stream (connection/flow).
Quality of Service (QoS): QoS functionality enables service providers to guarantee and enforce transmission quality parameters (e.g. bandwidth, jitter, delay, packet loss ratio) according to a specified service-level agreement (SLA) with the customer.
Multi Protocol Label Switching (MPLS): It lies between traditional definitions of Layer 2 (Data Link Layer) and Layer 3 (Network Layer). It provides a unified data-carrying service for both circuit-based clients and packet-switching clients, which provide a datagram service model. It can be used to carry many different kinds of traffic, including IP packets, as well as native ATM, SONET, and Ethernet frames.
Media Access Control (MAC): It is a sublayer of the Data Link Layer (DLL) specified in the Open Systems Interconnection Reference Model (OSI-RM). It provides addressing and channel access control mechanisms that make it possible for several terminals or network nodes to communicate within a multipoint network, typically a local area network (LAN) or metropolitan area network (MAN).