Aastra Telecom 6757I CT User Manual

Model 6757i CT IP Phone User Guide

 

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You can configure the phone to allow it to receive a Real Time Transport Protocol (RTP) stream 
from pre-configured multicast address(es) without involving SIP signaling. This is called Group 
Paging on the IP phones. You can specify up to 5 multicast addresses that the phone listens for on 
the network. This feature is configurable using the Aastra Web UI only.

The 6757i CT in the local network listens for RTP on the preconfigured multicast address. The 
Phone displays the “Paging” message to the phone’s LCD. It uses the G711 uLaw CODEC for 
multicast RTP. 

The recipient can drop the incoming page if required. The recipient can also set Do Not Disturb 
(DND) to ignore any incoming pages.

For incoming RTP multicasts, the ringing display is dependant on the setting for the “Allow 
Barge-In” parameter. (See 

 on 

.) If this parameter is disabled, and there 

is no other call on the phone, then the paging is automatically played via the default audio device.

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.