Modem and fax transmissions are legacy data technologies that will continue to be used for at least a decade. Modem and fax transmissions are delivered in two main layers:
 

• The data-pump layer: mainly V.92, V.90, V.34 in modem transmissions, and V.17, V.29, V.27ter in fax transmissions.
• The protocol layer: error correction/data compression in modem transmissions and T.30/T.38 in fax transmissions.

One of the key elements when choosing a vendor to provide data support is the ability to provide interoperability with commercially available fax and modems. SURF Communication Solutions has been providing fax and modem solutions to major tier-1 companies in the market since 1996.

Legacy data technologies (fax/modem) are incorporated in applications such as:
 

• Fax over IP gateways (T.38 gateway): A gateway to bridge between fax in its PSTN presentation (V.17, V.21 and fallbacks) and its IP presentation (T.38 or fax over G.711).
• Fax servers: A server that terminates or generates fax transmissions for both the PSTN and the IP network.
• Modem termination servers: A server that terminates or generates modem transmissions for the PSTN.
• Modem over IP gateways (V.150.1 gateway): A gateway to bridge between modem transmission in its PSTN presentation (V.90, V.34, V.32bis and fallbacks) and its IP presentation (V.150.1).
• Secure voice gateway: A majority of the secure voice phones are based on either transmissions of modem signals through the PSTN, or on the V.150.1 protocol on the IP network. Bridging between these two networks for secure voice applications requires the V.150.1 gateway module of the SURF Engine. SURF is the only authorized vendor providing enabling technology for this gateway, as SURF owns a significant portion of the relevant intellectual property (IPR).
• GSM/HSCSD fax gateway: A gateway to bridge between fax in its PSTN presentation (V.17, V.21) and its GSM/HSCSD presentation (GSM43.345).
• GSM/HSCSD modem gateway: A gateway to bridge between modem transmission in its PSTN presentation (V.34, V.42, V.44, and fallbacks) and its mobile presentation (V.110, A-TRAU, RLP, transparent, non-transparent, and fallbacks)

SURF offers solutions for all the above applications as an integral part of the SURF Engine. Its interoperability robustness and field hardening makes SURF Engine unmatched in the market today.

Also unmatched is the density the SURF Engine offers both modem- and fax-based applications: a single PCIe card can handle as much as 1,000 concurrent fax or modem transmissions, offering OEMs a drastic cost reduction.