T.30 Fax Transmission
The T.30 Fax Transmission Protocol defines the procedures which are necessary for document transmission between two facsimile terminals in the public switched telephone network.  Document transmission procedures involve five consecutive phases, including call establishment, pre-message procedure, message transmission, post-message procedure and call release.  Unicoi’s T.30 Fax Transmission software supports analog Group-3 fax machines. Fax transmission is used for fax server dial-in and dial-out services over a LAN, whereby users can send and receive faxes with their PCs. Fax transmission can also be used to implement store-and-forward fax services as well as fax-to-e-mail services.

T.38 Fax Relay
T.38 is an ITU standard for sending fax communications across IP networks in a real-time mode. Fax messages are sent as UDP or TCP/IP packets. Unicoi’s T.38 Fax Relay is an ITU recommendation for the transfer of real-time fax communications between two Group 3 fax terminal endpoints via an IP network.  Unicoi’s T.38 is the implementation of that standard licensed to developers of IP-PSTN gateways who require fax transport that meets PSTN standards.