
Description
This page describes a simple simulation of configuring multicast paging in UCM and IP Phones.
Steps:
- Go to UCM‘s Web UI > Call Features > Paging/Intercom > Configure Multicast IP Address and its port. The IP range is from 224.0.1.0 – 238.255.255.255

2. Go to IP Phone > Setting > Multicast Paging > Listening Address > enter the same Multicast IP Address and port as configured in UCM

3. Dial the paging extension (eg. ext. 8008) and the phones with the same Listening Address will auto-answer the paging call

Note
There are no user limitations, the only limitation is the network bandwidth and how the router treats the broadcast packets. It is not advised to send multicast transmission to a large group of users as it will cause network congestion.
The sender/Receiver must be located on the same LAN (same broadcast domain) in multicast paging calls. If the speaker .x is in a different subnet from the sender, this causes it not to receive the multicast paging.
Syslog Analysis
GS_AVS MulticastTransport MulticastTransport Info:\r\n\tread:[rtp:125] [rtcp:0] write:[rtp:0] [rtcp:2377]\n\tIncoming :125 Outcoming:2377 Symrtp:2 Drop:0\n\ttargetAddr:239.168.5.12:554 \n\tlocalAddr:192.168.0.212 multicastSrcAddr:192.168.0.160:0 bindCard:eth0\n\tmRTPPort:554 mRTCPPort:554 mbDTLS=0\n\tcrypto 0 s: r:\n
GSPHONE DEBUG [1.0.5.4][3037107168] Multicast(setMultiCallState):753:set channel:0, index: 0, state: 3\n
GSPHONE INFO [1.0.5.4][3037107168] Multicast(run):718:Posting multicast call received event pri: 0, channel: 0\n
GSPHONE INFO [1.0.5.4][3070058512] Event(run):902:Dispatching event: 183 (PHONE_MULTICAST_RECV) on line -1\n
GSPHONE DEBUG [1.0.5.4][3070058512] PhoneCallControl(processMulticastReceive):6691:processMulticastReceive: Start: 1, mcLine: -1, mcFinalPri: 5, priority: 4\n
GSPHONE DEBUG [1.0.5.4][3070058512] PhoneCallControl(getRingLine):15120:JF::getRing| acct: 0, number: 234.2.1.7:5012 ,appearance_index: -1\n
GSPHONE DEBUG [1.0.5.4][3070058512] PhoneCallControl(setStatus):15317:PhoneCallControl::setCallStatus callstatus: CALL_MULTICAST, status of line:[0]: CALL_MULTICAST, is Caller: 0\n
GSPHONE DEBUG [1.0.5.4][3070058512] Multicast(setActiveChan):1054:set active chan: 0\n