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Appendix D: Protocols Overview
iSPAN Serial WAN Adapter Users Guide
187
PVCs
PVCs are similar to leased lines because the connection is
always present. The logical connection is established
permanently by the Packet Switched Network administration.
Therefore, data may always be sent, without any call setup.
Frame Relay Protocol
Frame Relay is defined as a protocol-oriented packet-switched
technology offered by telephone companies.
Frame Relay depends on the concepts of Permanent Virtual
Circuits (PVCs) and Committed Information Rate (CIR).
A PVC is virtual because no wires or cables directly hook up
the local and remote peers (for example, your branch library
and the central library). The connection occurs in the
cloud
or
switch at the telephone company. A PVC is permanent because
as long as the computer at the telephone company is turned on,
the circuit remains established.
The CIR is the contracted communication rate (bandwidth)
you have negotiated with the telephone company, guaranteeing
your ability to transmit at a specified minimum speed all the
time. It is generally possible to transmit at much higher speeds,
by virtue of the nature of frame relay, but you will always
attain the CIR you negotiated.
Содержание iSPAN
Страница 1: ...iSPAN Serial WAN Adapter Users Guide Document No UG05535 002 A2 Release Date July 2002...
Страница 10: ......
Страница 30: ...Minimum System Requirements 10 Interphase Corporation...
Страница 38: ...Installing the Adapter 18 Interphase Corporation...
Страница 54: ...Connecting to the Network 34 Interphase Corporation...
Страница 142: ...Removing Base Driver Software 122 Interphase Corporation...
Страница 164: ...Inserting a Connection 144 Interphase Corporation...
Страница 184: ...Saving WAN Adapters Setup Properties 164 Interphase Corporation...
Страница 214: ...Europe 194 Interphase Corporation...
Страница 232: ...212 Interphase Corporation...