VOCAL V.151 Gateway is a standards based implementation that incorporates reliable and efficient transport of analog modulated signals generated by PSTN text telephone across IP network. This solution supports text over IP (ToIP) operation in Voice Band Data (VBD) mode and in the Text Relay (TR) mode. Possible connection scenarios may include PSTN Text Telephone at one end and another PSTN Text Telephone or an IP Text Telephone on the other end.
VOCAL’s v.151 implementation can be combined with other VOCAL v.15x series of recommendations like ITU-T V.150.1 for Modem-over-IP (MoIP) or ITU-T V.152 for VBD. Although for each V.15x recommendation, there is a requirement that the support for it has to negotiated with the remote gateway specifically.
Features:
Payload Type Indication – This default method for switching between transport modes using RTP payload types are supported in the gateways.
SSE – Signaling State Events are Supported, it is a mechanism by which the media states are synchronized between the media gateways.
SPRT – Simple Packet Relay Transport for text relay is supported along with different data types (I_OCTET, I_OCTET_CS, I_RAW_OCTET) to carry the data from one gateway to another.
SDP – Different variations of the Session description based on the requirement available, e.g., port sharing where you can send the SPRT and the RTP over the same port.
Interoperability – Our gateways use a number of modulations and character encodings with many other different vendors.
Scalability – A large number of channels on a single gateway can be supported, starting from 10s to 100s based on the gateway.
Flexibility – VOCAL’s V.151 Gateway runs in the form of hardware independent library for a number of the target environment platform (any standard Linux or Windows distribution).
Benefits:
ITU V.151 identifies different modes for transmitting text over IP networks.
TEXT Relay – the audio signal from the local test telephone is demodulated at the on-ramp gateway and transmitted over the network through the SPRT protocol and re-modulated at the off-ramp gateway for transmission to the local text telephone. The gateways maintain state for the call session.
Voiceband (VBD) – The signal is encoded by a speech codec such as G.711 and transmitted as data packets over the network. VBD mode may be used over reliable networks with predictable throughput and negligible packet loss.
Flexible Implementation:
VOCAL Technologies, Ltd.
520 Lee Entrance, Suite 202
Buffalo, NY 14228
Phone: +1 716-688-4675
Fax: +1 716-639-0713
Email: [email protected]
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