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ForeRunner
ATM Switch Network Configuration Manual
Configuring PVCs
1.4.1 Smart Permanent Virtual Circuits
Smart Permanent Virtual Circuits (SPVCs) are connections that go across multiple switch fab-
rics. An SPVC looks like a PVC at the local and remote endpoints with an SVC (Switched Vir-
tual Circuit) in the middle. SVCs are channels established on demand by network signalling.
Similar to a dialed telephone call, SVCs transport information between two locations and last
only for the duration of the transfer.
SPVCs are more robust than PVCs. If a link carrying a PVC goes down, then the PVC goes
down. If a link carrying a SPVC goes down and there is an alternate route, then the end switch
fabrics of the SPVC automatically reroute the SPVC around the failed link.
As shown in Figure 1.13, interswitch links exist between the ForeRunner switches. The end-
points exist at switch A and switch E. If a link goes down between switch A and switch B, an
SPVC can reroute the cell (via an SVC) through switch C.
Figure 1.13 -
The Path of a Cell Via SPVCs
ForeRunner
Switch
cell VPI: 1, VCI: 35
cell
VPI: 2, VCI: 33
port A4
port A1
A
B
D
E
ForeRunner
Switch
ForeRunner
Switch
ForeRunner
Switch
ForeRunner
Switch
C
SVCs
Interswitch Links
Содержание forerunner series
Страница 6: ......
Страница 16: ...TOC 10 ForeRunner ATM Switch Network Configuration Manual Table of Contents ...
Страница 20: ...LOF 4 ForeRunner ATM Switch Network Configuration Manual List of Figures ...
Страница 22: ...LOT 2 ForeRunner ATM Switch Network Configuration Manual List of Tables ...
Страница 30: ...viii ForeRunner ATM Switch Network Configuration Manual Preface ...
Страница 144: ...3 58 ForeRunner ATM Switch Network Configuration Manual Configuring an Emulated LAN ...
Страница 180: ...6 12 ForeRunner ATM Switch Network Configuration Manual ATM Forum PNNI ...
Страница 220: ...9 6 ForeRunner ATM Switch Network Configuration Manual Configuring Timing ...
Страница 300: ...D 24 ForeRunner ATM Switch Network Configuration Manual Configuring FramePlus Modules ...
Страница 308: ...Acronyms 8 ForeRunner ATM Switch Network Configuration Manual Acronyms ...
Страница 346: ...Glossary 38 ForeRunner ATM Switch Network Configuration Manual Glossary ...
Страница 352: ...Index 6 ForeRunner ATM Switch Network Configuration Manual Index ...