Fax Relay - T.38
Fax Over IP (FoIP)
The fax relay is fully compliant implementation of the ITU-T T.38 recommendation.
Features List
Supports facsimile modem modules:
- ITU‐T V.17 APSK trellis‐coded modem
- ITU‐T V.21, channel 2 FSK modem
- ITU‐T V.27ter QPSK/8PSK modem
- ITU‐T V.29 APSK modem
Availability
Platforms Armv7-A, Armv8-A, Armv9-A | Arm Cortex-A8/A9/A15 Texas Instruments – TI TMS320C6000 C64x/C64x+/C66x/C674x | TI TMS320C5000 C55x / C54x
ADT Fax Relay is available on the above Platforms: Other configurations are available upon request.
V. Facsimile Modulation Methods
V.17 APSK trellis‐coded modem
V.17 – Availability: C64x, C55x, C54x, Arm9E
This half-duplex modem is intended for use in FAX applications. It employs trellis coded modulation at data signaling rates of 7.2, 9.6, 12, and 14.4 kbit/s with a symbol rate of 2400 symbols per sec. The modulation methods are rectangular 16-QAM at 7.2 kbit/s, modified cross 32-QAM at 9.6 kbit/s, rectangular 64 -QAM at 12 kbit/s, and modified cross 128-QAM at 14.4 kbit/s. It includes an automatic adaptive equalizer, long-train and re-sync sequences, and optional Talker Echo Protection tone generation.rm
V.21 Channel 2 FSK modem
V.21 – Availability: C64x, C55x, C54x, Arm9E
This modem is used in fax and v.34 startup applications. It is a 2 channel modem operating at a data signaling rate of 300 bit/s with a symbol rate of 300 symbols/sec. The modulation method is continuous phase frequency shift keying (CP-FSK).
V.27ter QPSK/8PSK modem
V.27ter – Availability: C64x, C55x, C54x, Arm9E
This half/full duplex modem is used in half duplex FAX applications, and full duplex in leased-line applications. It employs QPSK and 8-PSK modulation at data signaling rates of 2.4 and 4.8 kbits/sec with symbol rates of 1200 and 1600 symbols/sec respectively. It includes an automatic adaptive equalizer, long and short training sequences, and optional Talker Echo Protection tone generation.
V.29 APSK modem
V.29 – Availability: C64x, C55x, C54x, Arm9E
This half duplex modem was intended for 4 wire operation but is used in FAX applications. It employs an unusual amplitude-phase shift modulation scheme at 4.8, 7.2, and 9.6 kbits/sec with a symbol rate of 2400 symbols/sec. It includes an automatic adaptive equalizer, long-train and re-sync sequences, and optional Talker Echo Protection tone generation.
VoIP Engine XP™*
*Fax software T.38 is included in Adaptive Digital’s LnxVoice™ Conference Bridge Solution
Description
The fax relay is fully compliant with the TCP and UDP implementation of the ITU-T T.38 Recommendation. All C code is ANSI compliant, so the user is assured compatibility with a custom target
The T.38 recommendation provides for real-time group 3 facsimile deliveries over Internet Protocols (IP). This recommendation permits the use of either TCP or UDP over IP for delivery of the facsimile, which would be any IP network, including the Internet.
The T.38 recommendation provides for real-time group 3 facsimile deliveries over Internet Protocols (IP). This recommendation permits the use of either TCP or UDP over IP for delivery of the facsimile, which would be any IP network, including the Internet.
The minimal configuration requires users to buffer network packets until the relay has enough memory to accept them.
Alternatively, the user can configure the relay with more internal memory so that network packets are accepted by the
relay when available.