Transmission Control Layer

The transmission control (TC) layer of SNA supplies the connection-point-manager function and the session-control function for each locally supported half-session. The connection-point-manager function controls sequence-number checking, pacing, and other support functions that relate to half-session data flows. The session-control function supplies session-specific support for starting, pacing, enciphering, deciphering, and other support functions that relate to session-related data flows. LUA contains an implementation of the TC layer for LU types 0, 1, 2, and 3 within Personal Communications.