Aastra 5i Series, Administrator'S Manual

Page: 396 / 1134

Operational Features
5-104 41-001160-01, Rev 00, Release 2.3
IP Phone Administrator Guide
How it works
After pressing a configured “Paging” key on the phone, the Phone sends RTP to a
preconfigured multicast address(es) (IP port). Any phone in the local network
then listens for RTP on the preconfigured multicast address(es) (IP port). For both
sending and receiving of the multicast RTP there is no sip signaling involved. The
Phone displays the multicast RTP sent/received address(es) to the user.
The phone uses a preconfigured G711 uLaw CODEC for multicast RTP.
For Paging Systems, the phone only plays RTP traffic; users have the ability to
drop a rogue page. 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 “ Allow
Barge-In ” parameter. If this parameter is disabled ,
and there is not other call
on the phone, then the paging is automatically played via the preferred
audio device (see the model-specific IP Phone User Guide for setting
Audio Mode on the phone).
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.
Note:
Multicast RTP is one way only - from sender to the receiver (i.e.
from sender to the multicast address(es) (receiver)).
Note:
For outgoing RTP multicasts, all other existing calls on the phone
are put on hold.