Cisco BPX 8650, Installation And Configuration Manual

Page: 406 / 606

23-26
Cisco BPX 8600 Series Installation and Configuration
Release 9.3.30, Part Number 78-12907-01 Rev. E0, May 2005
Chapter 23 Configuring BXM Virtual Switch Interface
Class of Service Templates and Qbins
Each VC added by a VSI master is assigned to a specific Service Class by means of a 32-bit service type
identifier. The following are the current identifiers:
• ATM Forum service types
•
Automatic Routing Management
•
MPLS Switching
When a connection setup request is received from the VSI master in the Label Switch Controller, the
VSI slave (in the BXM, for example) uses the service type identifier to index into a Service Class
Template database containing extended parameter settings for connections matching that index. The
slave uses these values to complete the connection setup and program the hardware.
One of the parameters specified for each service type is the particular BXM Class of Service buffer
(Qbin) to use. The Qbin buffers provide separation of service type to match the QoS requirements.
Service templates on the BPX are maintained by the BCC and are downloaded to the BXM cards as part
of the card configuration process for:
• Y-red card additions
•
BCC (control card) switchovers
•
Cards with active interfaces and that are reset (hardware reset)
•
BCC (control card) rebuilds
The templates are nonconfigurable.
Structure of Service Class Templates
There are three types of templates:
•
VSI Special Types
•
ATMF Types
• MPLS Types
You can assign any one of the nine templates to a Virtual Switch Interface (see Figure 23-9).
Each template table row includes an entry that defines the Qbin to be used for that Class of Service. See
Figure 23-9 for an illustration of how Service Class databases map to Qbins. This mapping defines a
relationship between the template and the interface Qbin’s configuration.
A Qbin template defines a default configuration for the set of Qbins for the logical interface. When a
template assignment is made to an interface, the corresponding default Qbin configuration becomes the
interface’s Qbin configuration.
Some of the parameters of the interface’s Qbin configuration can be changed on a per-interface basis.
Such changes affect only that interface’s Qbin configuration and no others, and do not affect the Qbin
templates.