# FAX Over IP Support - Conditions

The following conditions apply to facsimile (FAX) communication over IP networks using FAX Relay (T.38) protocol:

- This feature is supported on the following controllers:

- MXe III controller

- CX II, and CXi II controllers

- AX controller

- EX controller

- This feature is not supported on systems that have 256 MB of memory or less (not applicable for EX controllers).

- The DSP II (PN 50005751) module must be installed in the MiVoice Business controller (not applicable for EX controllers).

- 3300 ICP Release 9.0 or later software must be installed on the systems (all nodes within the signalling path must have Release 9.0 or later software).

- T.38 signaling can only terminate on 3300 Release 9.0 or later systems and third-party T.38 SIP capable gateways. Faxes that originate or terminate on pre-Release 9.0 systems, won't use FAX Relay (T.38) signalling.

- External third-party MiNET Applications, such as NuPoint Unified Messaging (Standalone) and MiCollab Nupoint UM , do not support FAX Relay (T.38) signalling. FAX Relay (T.38) signalling can be supported for NuPoint/MiCollab Nupoint UM if it is interfaced through SIP. To support this solution, a T1 card is installed in loopback mode. The FAX Relay (T.38) call is transferred to the T1 card and then looped back to the NuPoint/MiCollab Nupoint UM system.

- The maximum transmission rate for FAX Relay calls is V.17 (14.4 kbit/s).

- The system only supports data transmission over UDP for FAX Relay (T.38). The data is not encrypted.

- FAX Relay (T.38) channels are licensed in groups of four. Compression channels are licensed in groups of eight (not applicable for EX controllers).

- Upon detection of a modem tone, MiVoice Business will "upspeed" a FAX call to a higher-bandwidth, such as G.711 or FAX Relay (T.38), if the required system resources are available.

- MiVoice Business supports FAX logging for FAX Relay (T.38) calls. See Fax Log Enable for details. Note that G.711 pass thru faxes do not generate FAX logs (not applicable for EX controllers).

Related Topics

- FAX Over IP Support - Description

- Configure FAX Over IP Support