Media5 Mediatrix 4104, Справочное руководство, Страница: 103 / 466

Voice & Fax Codecs Reference Manual (SIP Version)
Mediatrix 4104 81
8. Set the payload type in the DTMF Payload Type field.
You can determine the actual RTP dynamic payload type used for the “telephone-event” in an initial
offer. The payload types available are as per RFC 1890. Available values range from 96 to 127.
9. Set the RTP Base Port field with the port number you want to use as RTP/RTCP base port.
The RTP/RTCP ports are allocated starting from the base port. The Mediatrix 4104 may use two or
four RTP/RTCP ports for each FXS interface:
• It uses two ports in case of a standard call.
• It uses four ports in other types of calls such as a conference call, a call transfer, etc.
The default RTP/RTCP base port is 5004 . In the case of the base port defined on 5004:
• If there is currently no ongoing call and FXS connector 1 has an incoming or outgoing
call, it uses the RTP/RTCP ports 5004 and 5005.
• If there is currently a standard call on FXS connector 1 and FXS connector 2 has a
conference call, then FXS connector 2 uses the RTP/RTCP ports 5006, 5007, 5008,
and 5009, which are the next available ports.
10. Select whether the echo cancellation should be enabled or disabled in the Echo Cancellation
choice.
Turning off the echo cancellation feature may be useful to ensure the success of some modem
transmissions.
11. Click Submit if you do not need to set other parameters.
About Changing Jitter Buffer Values
Media5 recommends to avoid changing the target and maximum jitter buffer values unless experiencing or
strongly expecting one of the following symptoms:

If the voice is scattered, try to increase the maximum jitter buffer value.

If the delay in the voice path (end to end) is too long, you can lower the target jitter value, but
ONLY if the end-to-end delay measured matches the target jitter value.
outOfBandUsingRtp The DTMFs are transmitted as per RFC 2833.
outOfBandUsingSignalingProtocol The DTMFs are transmitted as per draft-choudhuri-sip-info-
digit-00.txt .
Note : This feature and the Hook Flash processing feature
via signalling protocol are totally independent. Activating
one of these features has no effect on the other. See
“Hook
Flash Processing” on page 322 for more details.
signalingProtocolDependent The signalling protocol has the control to select the DTMF
transport mode. The SDP body includes both RFC 2833
and
draft-choudhuri-sip-info-digit-00.txt in that order of
preference.
Table 57: DTMF Transport Type Parameters (Continued)
Transport Parameter Description
Note:
This parameter applies only when selecting the outOfBandUsingRtp DTMF transport mode.
Table 58: Echo Cancellation Parameters
Parameter Description
disable The DSP does not use echo cancellation on the related port.
enable The DSP proceeds to cancel signals that are recognized as echo when
appropriate. This is the default value.