Appendix B: Integrating Cisco Unified Communications Manager and Cisco Unified SRST to Use Cisco Unified SRST
Information About Using Cisco Unified SRST Gateways as a Multicast MOH Resource
284
Cisco Unified SCCP and SIP SRST System Administrator Guide
OL-13143-04
Figure 1
Multicast MOH from Cisco Unified SRST Flash Memory
Codecs, Port Numbers, and IP Addresses
Cisco Unified SRST multicast MOH supports G.711 only.
Figure 2
shows an example in which G.711
is the only codec used by a central Cisco Unified CM and three branches. In some cases, a Cisco Unified
CM system may use additional codecs. For example, for bandwidth savings, Cisco Unified CM may use
G.711 for multicast MOH and G.729 for phone conversations.
As shown in the example in
Figure 2
, IP address 10.1.1.1 and port 1000 are used during phone
conversations when G.729 is in use, and IP address 239.1.1.1 and port 16384 are used when a call is
placed on hold and G.711 is in use.
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