IP Call Control Module T.38 Parameters
Fax Transporting Protocol:
[fax_transport_protocol] This parameter specifies how the fax media will be transported. Valid values are:
t38_only - Fax will use T.38 only and calls will fail if T.38 cannot be negotiated.
t38_never - Fax will use G.711 pass-through only.
t38_first - Fax will use T.38 with fallback to G.711 pass-through.
The default value for this parameter is 't38_only'.
Generate CED tone over RTP:
[rtp_ced_enable] This parameter specifies whether to generate CED tone over RTP on a T.38 call. If enabled generates CED tone using the RTP protocol for SIP and H.323 fax calls which do not immediately start as a T.38 fax call. If disabled CED tone is not generated.
Maximum Bit Rate, bps:
[t38_max_bit_rate] This parameter configures the maximum bit rate (in bits per second) for fax packetization on to the network.
Media Passthrough Timeout Inbound, msec:
[media_passthrough_timeout_inbound] This parameter sets whether media renegotiation will be attempted before doing fax passthrough on inbound calls when [media_renegotiate_delay_inbound] is set to -1 to disable initiating the media renegotiation to image, [fax_transport_protocol] is set to t38_first and the module supports fax passthrough. Numbers greater than 0, indicate the number of milliseconds to delay before attempting media renegotiation if the module supports fax passthrough. A value of 0 will cause an immediate renegotiation, while -1 will suppress renegotiation to fax passthrough.
Media Passthrough Timeout Outbound, msec:
[media_passthrough_timeout_outbound] This parameter sets the timer to fail over to fax passthrough when no T.38 is negotiated on outbound calls. This timer is active only when [media_renegotiate_delay_outbound] is set to -1 to disable initiating the media renegotiation to image, [fax_transport_protocol] is set to t38_first, and the module supports fax passthrough. Numbers greater than 0, indicate the number of milliseconds to wait for T.38 negotiation before performing fax passthrough. A value of 0 will cause an immediate renegotiation to passthrough, while -1 will suppress renegotiation to fax passthrough.
Media Renegotiate Delay Inbound, msec:
[media_renegotiate_delay_inbound] This parameter sets whether media renegotiation will be used on inbound calls. If media is initially negotiated for audio (as required for Cisco routers), this parameter controls who is responsible for media renegotiation to image on inbound calls. If Cisco router will be responsible for media renegotiation set this parameter to -1 to disable initiating the media renegotiation to image. If the UAC is responsible for media renegotiation to image set this parameter to a value between 0 and 60000. Numbers greater than 0, indicate the number of milliseconds to delay before attempting media renegotiation. The time difference between inbound and outbound media renegotiate delay should be at least 500 msec. A value of 0 will cause an immediate renegotiation, while -1 will wait for a renegotiation to image.
Media Renegotiate Delay Outbound, msec:
[media_renegotiate_delay_outbound] This parameter sets whether media renegotiation will be used on outbound calls. If media is initially negotiated for audio (as required for Cisco routers), this parameter controls who is responsible for media renegotiation to image on outbound calls. If Cisco router will be responsible for media renegotiation set this parameter to -1 to disable initiating the media renegotiation to image. If the UAC is responsible for media renegotiation to image set this parameter to a value between 0 and 60000. Numbers greater than 0, indicate the number of milliseconds to delay before attempting media renegotiation. The time difference between inbound and outbound media renegotiate delay should be at least 500 msec. A value of 0 will cause an immediate renegotiation, while -1 will wait for a renegotiation to image.
T30 Fast Notify:
[t38_t30_fastnotify] This parameter sets whether the transport signals the beginning of T.30 by means of a zero-length data field or by a T.30 indicator value.
UDPTL Redundancy Depth Control:
[t38_UDPTL_redundancy_depth_control] This parameter sets the number of prior messages to include as redundancy messages in a transmitted UDPTL packet carrying signal information (i.e., FSK signals).
UDPTL Redundancy Depth Image:
[t38_UDPTL_redundancy_depth_image] This parameter sets the number of prior messages to include as redundancy messages in a transmitted UDPTL packet carrying image data.
Advanced Settings
Maximum T.38 Version:
[t38_fax_version] The parameter specifies the maximum version offered or accepted by the chosen call control. This value is used in the T.38 Profile sent to the remote device as attibute T38FaxVersion.
Support G.711 Fallback SIP RTP reINVITE:
[g711_fallback_rtp_reinvite] This parameter is used to enable/disable G.711 Fallback SIP RTP reINVITE functionality.
Valid values are true and false.
The default value for this parameter is false.
T.38 Media Stream Renegotiation:
[t38_stream_renegotiation] This parameter specifies how the T.38 offer will be composed. Valid values are:
Single - The T.38 offer will be composed of only one media stream.
Replace - The T.38 offer will replace the active media stream.
Append - The T.38 offer will be appended to the end in a new media stream.
The default value for this parameter is 'Single'.
Type of Service (DSCP value):
[t38_type_of_service] This parameter is used for setting the value of the 6-bit Differentiated Services Code Point in the Differentiated Services field of the T.38 IP packet header.