3Com Switch 8800 Advanced Software V5 Configuration Guide

572 CHAPTER 42: PIM CONFIGURATION
Relationship between BSR admin-scope regions and the global scope zone
A better understanding of the global scope zone and BSR admin-scope regions
should be based on two aspects: geographical space and group address range.
1 Geographical space
BSR admin-scope regions are logical regions specific to particular multicast groups,
and each BSR admin-scope region must be geographically independent of
another, as shown in
Figure 180.
Figure 180 Relationship between BSR admin-scope regions and the global scope zone in
geographic space
BSR admin-scope regions are geographically segregated from one another.
Namely, a router must not serve different BSR admin-scope regions. In other
words, different BSR admin-scope regions contain different routers, whereas the
global scope zone covers all routers in the PIM-SM domain.
2 In terms of multicast group address ranges
Each BSR admin-scope region serves specific multicast groups. Usually, these
addresses have no intersections; however, they may overlap one another.
C-RP BSR
C-RP BSR C-RP BSR
Global
C-RP BSR
BSR 2
C-RP BSR
BSR 1
C-RP BSR
BSR 3