Frame Relay

communications A DTE-DCE interface specification based

on LAPD (Q.921), the Integrated Services Digital Network

version of LAPB (X.25 data link layer). A common

specification was produced by a consortium of StrataCom,

Cisco, Digital, and Northern Telecom.

Frame Relay is the result of wide area networking

requirements for speed; LAN-WAN and LAN-LAN

internetworking; "bursty" data communications; multiplicity

of protocols and protocol transparency. These

requirements can be met with technology such as opticalfibre lines, allowing higher speeds and fewer transmission

errors; intelligent network end devices (personal computers,

workstations, and servers); standardisation and adoption

of ISDN protocols. Frame Relay could connect dedicated lines

and X.25 to ATM, SMDS, BISDN and other "fast packet"

technologies.

Frame Relay uses the same basic data link layer framing and

Frame Check Sequence so current X.25 hardware still works.

It adds addressing (a 10-bit Data Link Connection Identifier

(DLCI)) and a few control bits but does not include

retransmissions, link establishment, windows or error

recovery. It has none of X.25's session layer but adds some

simple interface management. Any network layer protocol can

be used over the data link layer Frames.

Frame Relay Resource Center.

(2000-07-14)