User's Manual

Doc. No.
Rev.
Date
DRAFT
1.01
2012-01-27
Damm Cellular Systems A/S, Denmark
TetraFlex
®
7.5 Manual - IP Backbone network layout and
configuration
TetraFlex® 7.5 Manual 2-154
for both the signaling group and the log server group. The joining of the two groups will be
active for as long as the BSC is active.
When a call is initiated, it is signaled to all other BSC on multicast group .1. All other active
BSC will receive this message. The signaling makes it possible for all the BSC’s to decide
whether a given call is relevant to any terminal under its control. At same time – the
originating BSC will assign a CMoIP address to the actual call and send an IGMP join
message to the network to create the group in the routers. The address of this given group is
contained in the signaling.
Any BSC that has interest in receiving the packets from the CMoIP group will make an IGMP
join on the CMoIP address. After the call activity is terminated – the given CMoIP group will
be taken down by IGMP disjoin messages.
The above mechanism is used both for group calls, full duplex calls, semi duplex calls and
voice gateway calls.
Figure 2-53: BSC multicast settings
If you need to alter any of these settings – use the following commands:
Figure 2-54: Applicable OM commands
Don’t forget that in TetraOM, pressing “F1” will open the help files.