SUMMARY

This Recommendation specifies the protocols to be used to provide OSI connection mode network service to applications entities such as MHS entities (e.g. UA, MTA, MS) when communicating in an asynchronous environment (i.e. start/stop transmissions) over a telephone network.

The communication can be directly over a telephone network connection, or over a telephone network connection to a PSDN through a PAD, or over a telephone network connection to a PSDN using the packet mode.