Yealink SIP-T48G User Manual page 229

The following figure shows a multicast RTP session on the phone:
You can do the following:
2.
Tap the Hold soft key to place the current multicast RTP session on hold.

The sender's phone places the multicast RTP session on hold and receiver's phone
releases the session.
To resume the held multicast RTP session, tap the Resume soft key.
The multicast RTP session is established again.
Tap the End Call soft key to end the multicast RTP session.

Note
Multicast RTP is one way only from the sender to the multicast address(es) (receiver). For
outgoing RTP multicasts, all other existing calls on the phone will be placed on hold.
To send RTP stream via a paging key list when the receiver's phone is idle:
Tap the paging list key when the phone is idle.
1.
Tap the desired paging group.
2.
Tap the Paging soft key to send RTP.
3.
Advanced Phone Features
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