SPIRIT Realtime T.38 Fax Gateway allows users to forward common fax calls
via generic packet networks (e.g. Internet). It implements real-time gateway
according to F.185 Recommendation definitions. This makes it possible to
utilize an existing data network for economical fax transmissions, because
packet-switched networks are normally much cheaper than PSTN. VoIP
Gateways are hardly useful in such conditions, since low-bit-rate vocoders are
poorly suitable for fax message coding. On the other hand, high-speed
vocoders (such as G.711) have issues with continuity and synchronization. The
solution proposed by ITU-T is described in T.38 recommendation; it allows to
implement reliable real-time fax relay over packet networks.
Features
Supports all features of Group 3 faxes, including ECM mode
Tolerant toward high jitter in packet network
IP bandwidth can be split to send/receive multiple faxes at the same time
Redundancy mechanism providing packet loss prevention
