Emulex DCP_link manual Introduction, Frame Relay Networks

6-2 Chapter 6

Introduction

Emulex Frame Relay software is a streamlined, connection-oriented frame- mode data service based on frame-switching /relaying technology--the process of quickly transporting HDLC (High-level Data Link Control) frames through a network.

This software is based on Frame Relay, a WAN telecommunications protocol standard specified by the International Consultative Committee for Telegraphy and Telephony (CCITT) and ANSI (American National Standards Institute). Frame Relay was originally specified by CCITT as an Integrated Services Digital Network (ISDN) frame-mode service.

Emulex Frame Relay supports AppleTalk, Transmission Control Protocol/Internet Protocol (TCP/IP), Internetwork Packet Exchange (IPX) protocol, and the Source Route Bridge protocol of the NetWare MultiProtocol Router 3.0 software.

Frame Relay Networks

Private line networks permanently allocate dedicated transmission resources between communication end points, regardless of traffic conditions. The Frame Relay network uses statistical multiplexing. Transmission resources are not allocated until active communications exist. Network resources are shared dynamically among participating end points.

Frame Relay networks provide the best features of TDM (time division multiplexing): high-speed, low-delay circuit switching and the statistical multiplexing and port sharing of X.25 packet-switching technologies. These advantages guarantee bandwidth according to the set committed information rate (CIR), and allow bandwidth-on-demand bursts when available.

The Frame Relay network consists of Frame Relay switches, which usually are owned and administered by the carriers. The access connection to the Frame Relay network is typically provided by a Local Exchange Carrier (LEC) and can also be bundled into the Frame Relay provider's service. A network provider can be an LEC; a Metropolitan Frame Relay service, an Interexchange Carrier (IXC), an interstate, national, or global Frame Relay service.