• BNR_Down :- this message is sent by a BNR to its downstream BNRs and LMRs
stored in its MFT table. This message is sent in periodical time interval to refresh
the links between the BNR and its downstream members. Figure 5.5 shows
BNR_Down message format.
|
0 |
7 15 |
31 |
|
Source ( Current BNR IP address) | ||
|
Destination (next BNR/LMR IP address)[1] . | ||
|
. Destination (next BNR/LMR IP address) [N] | ||
Figure 5.5 BNR_Down message format
• Link_failure:- this message is sent by the BNR to its downstream BNRs and
LMRs stored in its MFT table, which is used to notify them that a link failure to
the upstream nodes has happened. This message is created and sent if the BNR
does not receive a BNR_Down from its upstream BNR. Figure 5.6 shows the
Link_failure message format.
|
0 |
7 15 |
31 |
|
Source ( Current BNR IP address) | ||
|
Destination (next BNR/LMR IP address)[1] . | ||
|
. Destination (next BNR/LMR IP address) [N] | ||
Figure 5.6 Link_failure message format
Regarding the new type of messages, new operations are implemented for SARM to
guarantee the multicast tree connectivity. These operations can be called the recovery
operations, because these operations are used to recover the construction of multicast
session after link failure because of mobility. These operations will be discussed in the
next section.
110