資料來源 : Free On-Line Dictionary of Computing
Frame Relay
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 network}ing
requirements for speed; {LAN}-{WAN} and LAN-LAN
{internetworking}; "bursty" data communications; multiplicity
of {protocol}s and {protocol transparency}. These
requirements can be met with technology such as {optical
fibre} 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
(http://www.alliancedatacom.com/framerelay.asp)}.
(2000-07-14)