User`s manual

SIP User's Manual 6. Gateway's ini File Configuration
Version 5.0 161 October 2006
Table 6-7: SIP Configuration Parameters (continues on pages 150 to 169)
ini File Field Name
Web Parameter Name
Valid Range and Description
TransparentCoderOnDataCa
ll
0 = Only use coders from the coder list (default).
1 = Use transparent coder for data calls (according to RFC 4040).
The ‘Transparent’ coder can be used on data calls. When the gateway
receives a Setup message from the ISDN with ‘TransferCapabilities = data’, it
can initiate a call using the coder ‘Transparent’ (even if the coder is not
included in the coder list).
The initiated INVITE includes the following SDP attribute:
a=rtpmap:97 CLEARMODE/8000
The default Payload Type is set according to the CoderName table. If the
Transparent coder is not set in the Coders table, the default value is set to 56.
The Payload Type is negotiated with the remote side, i.e., the selected
Payload Type is according to the remote side selection.
The receiving gateway must include the ‘Transparent’ coder in its coder list.
IsFaxUsed
[Fax Signaling Method]
Determines the SIP signaling method used to establish and convey a fax
session after a fax is detected.
0 = No fax negotiation using SIP signaling (default).
1 = Initiates T.38 fax relay.
2 = Initiates fax using the coder G.711 A-law/µ-law with adaptations (refer to
note 1).
3 = Initiates T.38 fax relay. If the T.38 negotiation fails, the gateway re-initiates
a fax session using the coder G.711 A-law/µ-law with adaptations (see note 1).
Note 1: Fax adaptations:
Echo Canceller = On
Silence Compression = Off
Echo Canceller Non-Linear Processor Mode = Off
Dynamic Jitter Buffer Minimum Delay = 40
Dynamic Jitter Buffer Optimization Factor = 13
Note 2: If the gateway initiates a fax session using G.711 (option 2 and
possibly 3), a ‘gpmd’ attribute is added to the SDP in the following format:
For A-law: ‘a=gpmd:0 vbd=yes;ecan=on’. For µ-law: ‘a=gpmd:8
vbd=yes;ecan=on’.
Note 3: When ‘IsFaxUsed’ is set to 1, 2 or 3 the parameter
‘FaxTransportMode’ is ignored.
Note 4: When the value of IsFaxUsed is other than 1, T.38 might still be used
without the control protocol’s involvement. To completely disable T.38, set
FaxTransportMode to a value other than 1.
T38UseRTPPort
Defines that the T.38 packets are sent / received using the same port as RTP
packets.
0 = Use the RTP port +2 to send / receive T.38 packets (default).
1 = Use the same port as the RTP port to send / receive T.38 packets.
CngDetectorMode
[CNG Detector Mode]
0 = Disable (default). Don’t detect CNG.
1 = Relay. CNG is detected on the originating side. CNG packets are sent to
the remote side according to T.38 (if IsFaxUsed=1) and the fax session is
started.
2 = Events Only. CNG is detected on the originating side. The CNG signal
passes transparently to the remote side and fax session is started.
Usually T.38 fax session starts when the ‘preamble’ signal is detected by the
answering side. Some SIP gateways don’t support the detection of this fax
signal on the answering side, thus, for these cases it is possible to configure
the gateways to start the T.38 fax session when the CNG tone is detected by
the originating side. However, this mode is not recommended.