25-7
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
How Virtual Trunking Works
Figure 25-4 Virtual Trunks across a Public ATM Network
Routing with Virtual Trunks
AutoRoute, PNNI, and MPLS each use different routing mechanisms. However, the routing
mechanisms meet the following criteria when dealing with virtual trunks:
•
Virtual Trunk Existence
Routing has special restrictions and conid assignments for a virtual trunk. For example, VPC’s may
not be routed over a virtual trunk.
•
Traffic Classes
The unique characteristics of CBR, VBR, and ABR traffic are maintained through the cloud as long
as the correct type of virtual trunk is used. You configure the traffic classes allowed per virtual
trunk by using cnftrk. The routing algorithm excludes virtual trunks whose traffic class is not
compatible with the candidate connection to be routed.
•
Connection Identifier (Conid) Capacity
Each virtual trunk has a configurable number of connection channels reserved from the card. The
routing algorithm checks for adequate channel availability on a virtual trunk before selecting the
trunk for a route.
The characteristics of a virtual trunk used by connection routing are maintained throughout the network.
This information—virtual trunk existence, traffic classes and connection channels—is sent to every
node to allow the routing algorithm to use the trunk correctly. Routing uses only those virtual trunks
that can support the traffic type of the connection.
Virtual trunking is supported by these features:
Public ATM network
ATM-UNI
ATM-UNI
17712
BXM 4
IGX 10
4.3.1
10.2.1
4.3
10.2
VPCs within the cloud,
one for each virtual trunk
(Virtual trunks can be
type CBR, VBR, or ABR)
BPX_A
IGX_A
BXM 5
BPX_B
4.3.2
10.2.3
5.1.1
5.1.2
5.1
Содержание BPX 8600 Series
Страница 43: ...P A R T 1 The BPX Switch ...
Страница 44: ......
Страница 151: ...P A R T 2 Installation ...
Страница 152: ......
Страница 261: ...P A R T 3 Initial Configuration and Network Management ...
Страница 262: ......
Страница 291: ...P A R T 4 Configuring Connections ...
Страница 292: ......
Страница 481: ...P A R T 5 Troubleshooting and Maintenance ...
Страница 482: ......
Страница 531: ...P A R T 6 BPX Specifications ...
Страница 532: ......
Страница 563: ...P A R T 7 Appendices ...
Страница 564: ......
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 ...