P.RG F4202N
© (2010) Pirelli Broadband Solutions S.p.A. All Rights Reserved. Proprietary Use Pursuant to Cover Page Instructions.
Voice over IP Section
HBK 939800036-A1
63
Signaling Protocol.
The signaling protocol options available in the combo-box,
are determined by the VoIP stack on your gateway.
A different subset of parameters will become visible with each of the combo-box
choices. To apply the change of protocol you must press either 'OK' or 'Apply'. If
the applied protocol is of another stack, the Router will reboot after you accept
the reboot warning.
RTP.
Local RTP Port Range defines the port range for Real Time Protocol
(RTP) voice transport.
Quality of Service.
Type of Service (HEX) This is a part of the IP header that
defines the type of routing service to be used to tag outgoing voice packets
originated from the Router. It is used to tell routers along the way that this
packet should get specific QoS. Leave this value as 0XB8 (default) if you are
unfamiliar with the differentiated Services IP protocol parameter.
Codecs.
Codecs define the method of relaying voice data. Different codecs
have different characteristics, such as data compression and voice quality. For
example, G.723 is a codec that uses compression, so it is good for use where
bandwidth is limited but its voice quality is not as good compared to other co-
decs such as the G.711.
Silence Suppression.
The Silence Suppression feature allows optimization to
be made when no speech is detected. With this feature enabled, the Router is
able to detect the absence of audio and conserve bandwidth by preventing the
transmission of "silent packets" over the network.
Echo Cancellation.
Echo Cancellation is the elimination of reflected signals
(echoes) made noticeable by delay in the network. his also improves the band-
width of the line. When the delay of a voice call exceeds acceptable limits, the
router will protect the far end from receiving any echo generated at the local end
and sent back through the network.