Aastra 6751i User Manual page 108

If there is an existing call on the phone, the call initially displays in the ringing state. The user
has the option to accept/ignore the call. If the "Allow Barge-In" parameter is enabled, the RTP
multicast call barges in, and any existing calls are put on hold.
If an RTP multicast session already exists on the phone, and the phone receives another
incoming RTP multicast session, the priority is given to the first multicast session and the second
multicast session is ignored. The behavior for the incoming calls in this case is also based on the
setting for the "Allow Barge-in" parameter. The incoming call is handled as if there were an
existing call already on the phone.
Configuring Group RTP Paging
Aastra Web UI
Use the following procedure to configure RTP streaming on the receiving end for Paging
applications using the Aastra Web UI.
1. Click on Basic Settings->Preferences->Group Paging RTP Settings.
2. In the "Paging Listen Addresses" text box, enter the multicast IP address(es) and port
number on which the phone listens for incoming multicast RTP packets.
Enter the IP address in dotted decimal format.
(for example, 239.0.1.15:10000,239.0.1.20:15000)
If this field is blank, the Paging Listening capability is disabled on the phone.
3. Click
100
Group Paging RTP Settings
to save your settings.
Model 6751i IP Phone User Guide