Complete Communications Engineering

V.42 / V.42bis Error Correction SoftwareV.42 / V.42bis software implements the ITU-T V.42 error correction protocols including MNP2-4, MNP5, and MNP10 data protocols. In addition, both LAPM (Link Access Procedure for Modems) and an alternate protocol are supported. The alternate, as described by V.42, is the MNP (Microcom Networking Protocol) data protocol, classes 2 through 4. LAPM and MNP2-4 implement end-to-end error correction through an automatic repeat-transmission request algorithm. Contact us to discuss your modem application requirements.

download brochure for V.42 / V.42bis Error Correction Software

Virtual Modem over IP

VOCAL’s SIP Software modem (MoIP or V.MoIP) solution provides developers a range of solutions to connect legacy dial up modems to modem infrastructure. Unlike other virtual modem designs, the SIP software modem can communicate with a physical modem at the far end using a VoIP service over an IP network.

VOCAL’s V.42 / V.42bis modem software is optimized for performance on leading DSP architectures and processors from TI, Intel, ADI, AMD and other vendors. Our V.42 software  may be licensed standalone, as a library or part of complete design. Custom solutions are also available.

V.42 and V.42bis Software Features

V.42bis and MNP 5 Data Compression

VOCAL’s modem protocols provide software developers a compression capability with ITU-T V.42bis and MNP5 algorithms. The V.42bis data compression protocol is sometimes used standalone. Classically, V.42bis has been used with LAPM and MNP5 is used with classes 2-4.

MNP2-4 / MNP 5 / MNP 10 Data Protocols

MNP2 is an error correction algorithm using data packets of asynchronous characters over a full-duplex modulation while MNP3 introduced the use of HDLC based synchronous packets. MNP4 can be used with or without the class 3 protocol feature; it provides for the use of slightly smaller (through optimized headers) data and acknowledge packets.


More Information

supported platforms for V.42 / V.42bis Error Correction Software

VOCAL’s optimized software is available for the above platforms. Please contact us for specific V.42 and V.42bis supported platforms.