TP-Link T2700G-28TQ T2700G-28TQ User Guide V1 - Page 265

Asserting, BSR Administrative Domain, BSR Domain Divided by Multicast Address

Page 265 highlights

(2) The receiver-side DR sends prune message toward the RP hop-by-hop. The RP will forward the received prune message toward the multicast source. The switching process from RPT to SPT is then accomplished. After the switching from RPT to SPT, the multicast data will be sent from multicast source to the receivers directly. Through this switching process from RPT to SPT, PIM SM constructs the SPT in a more economical way than PIM DM does.  Asserting The assert mechanism of PIM SM and PIM DM is the same. For more details, refer to Assert Mechanism.  BSR Administrative Domain BSR is the administrative core in the PIM SM domain. The BSR is exclusive in one PIM SM domain and it advertises the RP-Set information in the whole PIM SM domain. All the multicast group information is forwarded inside the BSR's administrative network scope. When the PIM SM domain is relatively large, you can consider dividing the PIM SM domain into multiple BSR administrative domains, thus sharing the administrative pressure of single BSR and providing specialized services for specific multicast groups. In geographical space, the BSR administrative domains are separated with each other and one router cannot belong to more than one BSR domain. In other words, the routers contained by the BSR domains are different from each other. In multicast address, each BSR administrative domain provides services for specific multicast groups. These multicast group addresses usually have no intersection with each other, but they may also have crossings and overlaps, as shown in Figure 11-19. Figure 11-19 BSR Domain Divided by Multicast Address Features of BSR administrative domain:  Divide the BSR administrative domains by setting BSR border Each BSR administrative domain has its own border, C-RP and BSR devices. These devices are only valid in their belonged domains, which means that the BSR mechanism and RP election are separated between their administrative domains.  BSR messages cannot pass through the BSR border 253

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253
(2)
The receiver-side DR sends prune message toward the RP hop-by-hop. The RP will forward
the received prune message toward the multicast source. The switching process from RPT to
SPT is then accomplished.
After the switching from RPT to SPT, the multicast data will be sent from multicast source to the
receivers directly. Through this switching process from RPT to SPT, PIM SM constructs the SPT in
a more economical way than PIM DM does.
Asserting
The assert mechanism of PIM SM and PIM DM is the same. For more details, refer to
Assert
Mechanism
.
BSR Administrative Domain
BSR is the administrative core in the PIM SM domain. The BSR is exclusive in one PIM SM
domain and it advertises the RP-Set information in the whole PIM SM domain. All the multicast
group information is forwarded inside the BSR’s administrative network scope. When the PIM SM
domain is relatively large, you can consider dividing the PIM SM domain into multiple BSR
administrative domains, thus sharing the administrative pressure of single BSR and providing
specialized services for specific multicast groups.
In geographical space, the BSR administrative domains are separated with each other and one
router cannot belong to more than one BSR domain. In other words, the routers contained by the
BSR domains are different from each other.
In multicast address, each BSR administrative domain provides services for specific multicast
groups. These multicast group addresses usually have no intersection with each other, but they
may also have crossings and overlaps, as shown in Figure 11-19.
Figure 11-19 BSR Domain Divided by Multicast Address
Features of BSR administrative domain:
Divide the BSR administrative domains by setting BSR border
Each BSR administrative domain has its own border, C-RP and BSR devices. These devices are
only valid in their belonged domains, which means that the BSR mechanism and RP election are
separated between their administrative domains.
BSR messages cannot pass through the BSR border