25-3
Cisco BPX 8600 Series Installation and Configuration
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
Chapter 25 Configuring BXM Virtual Trunks
Overview
Figure 25-1 Typical ATM Hybrid Network using Virtual Trunks
Benefits of Virtual Trunking
Virtual trunking benefits include:
•
Reduced cost by dividing a single physical trunk’s resources among a number of virtual (logical)
trunks. Each of these virtual trunks supplied by the public carrier need be assigned only as much
bandwidth as needed instead of the full T3, E3, OC-3, or OC-12 bandwidth of an entire physical
trunk.
•
Migration of PNNI and MPLS services into existing networks.
VSI Virtual Trunks allow PNNI or MPLS services to be carried over part of a network that does not
support PNNI or MPLS services. The part of the network that does not support PNNI or MPLS may
be a public ATM network, or simply consist of switches that have not yet had PNNI or MPLS
enabled.
•
Utilization of the full mesh capability of the public carrier to reduce the number of leased lines
needed between nodes in the Cisco WAN switching networks.
•
Choice of keeping existing leased lines between nodes, but using virtual trunks for backup.
•
Ability to connect BXM trunk interfaces to a public network using standard ATM UNI cell format.
•
Virtual trunking can be provisioned via either a Public ATM Cloud or a Cisco WAN switching ATM
cloud.
The BXM card provides several combinations of numbers of VIs, ports, and channels as listed in
Table 25-1, depending on the specific BXM card.
Public ATM network
Leased line
Leased line
ATM-UNI
ATM-UNI
ATM-UNI
17721
Cisco
subnetwork
Cisco
subnetwork
Cisco
subnetwork
Содержание BPX 8600 Series
Страница 43: ...P A R T 1 The BPX Switch ...
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Страница 151: ...P A R T 2 Installation ...
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Страница 261: ...P A R T 3 Initial Configuration and Network Management ...
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Страница 291: ...P A R T 4 Configuring Connections ...
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Страница 481: ...P A R T 5 Troubleshooting and Maintenance ...
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Страница 531: ...P A R T 6 BPX Specifications ...
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Страница 563: ...P A R T 7 Appendices ...
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Страница 624: ...Glossary 24 Cisco BPX 8600 Series Installation and Configuration Release 9 3 0 Part Number 78 10674 01 Rev D0 July 2001 ...
Страница 630: ...Index 6 Cisco BPX 8600 Series Installation and Configuration Release 9 3 0 Part Number 78 10674 01 Rev D0 July 2001 ...