User Guide for the SIP-T48S IP Phone206to people who are listening to a specific multicast group. You can configure a multicast pagingkey or a paging list key on the phone, which allows you to send a Real Time Transport Protocol(RTP) stream to the pre-configured multicast address(es) without involving SIP signaling. Youcan configure the phone to receive an RTP stream from pre-configured multicast listeningaddress(es) without involving SIP signaling. You can specify up to 31 multicast listeningaddresses.Yealink IP phone supports the following 31 channels: 0: It is the default channel. This channel is for compatibility with the Yealink IP phonesrunning firmware version 80 or prior and third-party devices. 1 to 25: These channels are for compatibility with the Polycom IP phones. 26 to 30: These channels are used for separate communication among the Yealink IPphones running firmware version 81 or later.The IP phones will automatically ignore all incoming multicast paging calls on the differentchannel.Sending RTP StreamTo configure a multicast paging key via phone user interface:1. Tap More.2. Tap the desired line key.3. Tap the gray box of the Type field, and then select Key Event from the pull-down list.4. Tap the gray box of the Key Type field, and then select Multicast Paging from thepull-down list.5. (Optional.) Enter the string that will appear on the touch screen in the Label field.6. Enter the multicast IP address and port number (e.g., 224.5.6.20:10008) in the Value field.The valid multicast IP addresses range from 224.0.0.0 to 239.255.255.255.7. Enter the desired channel in the Channel field.
