To create or modify a Fax Profile:
From the Create Media Profile drop down box at the top of the Media Profiles page, select Fax Codec Profile.
Specifies whether or not the T.38 will fall back to Fax Passthrough if not supported by peer.
If fallback is disabled and the SBC Edge (SBC) detects a fax call and attempts to switch-over to T.38 mode, the call fails if the peer gateway does not support T.38 protocols.
If fallback is enabled under the same circumstances as above, then when T.38 switch-over fails, the SBC attempts to switch-over to the G.711 codec (if the peer supports it).
Specifies the maximum FAX connection bit rate (bits/second).
This is the maximum rate at which a fax call will be negotiated between the SBC and the fax machine. It takes longer to transfer a page at lower rate, however, lower rate may make the fax call more reliable.
Specifies the number of redundant packets sent for each T.30 (signaling) message.
In a T.38 fax call, there are two types of packets exchanged between the two gateways: signaling packets carrying fax call control information and payload packets carrying page data. The Signaling Packet Redundancy parameter controls the number of redundant packets sent by SBC for each T.38 signaling packet. Use a low value for this parameter if the data network is of good quality with no or little packet loss.
Specifies the number of redundant packets sent for each packet containing page data.
This feature is similar to the Signaling Packet Redundancy feature, except that it applies to the payload packets instead of signaling packets.
Specifies the error correction mode (ECM) for fax calls.
ECM is used to make the fax call reliable (using retransmissions between fax machines). When disabled in the SBC configuration, ECM will not be used, even if both fax machines support it.
Specifies the Training Confirmation (TCF) procedure for fax calls.
Note: For the SBC SWe Lite, this field is set to Send over the Network and is not configurable. For the SBC 1000/2000, both options are available.
Note: This parameter is not applicable for the SBC SWe Lite.
Super G3 to G3 Fallback is applicable to fax calls in TDM-to-IP or IP-to-TDM directions. It is not applicable to TDM-to-TDM or IP-to-IP fax calls.
The Super G3 to G3 Fallback feature enables the SBC to unconditionally use T.38 protocol between two Super G3 fax machines. The call is always negotiated as if it were a G3-to-G3 fax call. Available options: Enabled (T.38 protocol is always negotiated between two Super G3 fax machines), or Disabled (T.38 protocol may not be negotiated between two Super G3 fax machines. Under many conditions, the call may come up as a modem pass-through call).
T.38 must be properly configured in the SBC according to the following guidelines: