Benefits Of Virtual Trunking; Figure 25-1 Typical Atm Hybrid Network Using Virtual Trunks; Table - Cisco BPX-BXM-155-8DX Installation And Configuration Manual

Chapter 25 Configuring BXM Virtual Trunks

Figure 25-1 Typical ATM Hybrid Network using Virtual Trunks

subnetwork

Benefits of Virtual Trunking

Virtual trunking benefits include:
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•
•
•
•
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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.
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
Cisco
ATM-UNI
Public ATM network
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.
Leased line
ATM-UNI
Cisco
ATM-UNI
subnetwork
Cisco BPX 8600 Series Installation and Configuration
Cisco
subnetwork
Leased line
Overview
25-3