User`s manual

MediaPack SIP
MediaPack SIP User’s Manual 178 Document #: LTRT-65405
• Detection of Reorder / Busy tones -
The call is immediately disconnected after Reorder / Busy tone is detected on the Tel side
(assuming the PBX / CO produces this tone). This method requires the correct tone
frequencies and cadence to be defined in the Call Progress Tones file. If these frequencies
are not known, define them in the CPT file (the tone produced by the PBX / CO must be
recorded and its frequencies analyzed). This method is slightly less reliable than the
previous one. You can use the CPTWizaed (described in Section
D.1.3 on page 274) to
analyze Call Progress Tones generated by any PBX or telephone network.
Relevant parameter: TimeForReorderTone.
• Detection of silence -
The call is disconnected after silence is detected on both call directions for a specific
(configurable) amount of time. The call isn’t disconnected immediately; therefore, this
method should only be used as a backup.
Relevant parameters: EnableSilenceDisconnect and FarEndDisconnectSilencePeriod (with
DSP templates number 2 or 3).
• A special DTMF code -
A digit pattern that, when received from the Tel side, indicates the gateway to disconnect the
call.
Relevant ini file parameter: TelDisconnectCode.
• Interruption of RTP stream -
Relevant parameters: BrokenConnectionEventTimeout and
DisconnectOnBrokenConnection. Note that this method operates correctly only if silence
suppression is not used.
• Protocol-based termination of the call from the IP side.
8.5 ThroughPacket™
The gateway supports a proprietary method to aggregate RTP streams from several channels to
reduce the bandwidth overhead caused by the attached Ethernet, IP, UDP and RTP headers, and
to reduce the packet / data transmission rate. This option reduces the load on network routers
and can typically save 50% (e.g., for G.723) on IP bandwidth.
ThroughPacket™ is accomplished by aggregating payloads from several channels that are sent
to the same destination IP address into a single IP packet.
ThroughPacket™ can be applied to the entire gateway or, using IP Profile, to specific IP
destinations (refer to Section
5.5.5.3 on page 95). Note that ThroughPacket™ must be enabled
on both gateways.
To enable ThroughPacket™ set the parameter ‘RemoteBaseUDPPort’ to a nonzero value. Note
that the value of ‘RemoteBaseUDPPort’ on the local gateway must equal the value of
‘BaseUDPPort’ of the remote gateway. The gateway uses these parameters to identify and
distribute the payloads from the received multiplexed IP packet to the relevant channels.
In ThroughPacket™ mode, the gateway uses a single UDP port for all incoming multiplexed
packets and a different port for outgoing packets. These ports are configured using the
parameters ‘L1L1ComplexTxUDPPort’ and ‘L1L1ComplexRxUDPPort’.
When ThroughPacket™ is used the following options aren’t available:
• DTMF transport using RFC 2833 (DTMFs should be transported out-of-band).
• Call statistics (since there is no RTCP flow).
8.6 Dynamic Jitter Buffer Operation
Voice frames are transmitted at a fixed rate. If the frames arrive at the other end at the same rate,
voice quality is perceived as good. In many cases, however, some frames can arrive slightly
faster or slower than the other frames. This is called jitter (delay variation), and degrades the