What Is a Mode Name?

LU 6.2 associates each session with a set of characteristics called a mode name. Mode names define characteristics such as pacing levels and class of service. Examples of pacing levels and classes of service are secure, ASCII data, satellite communication, high speed, batch, and interactive. When transaction programs request a conversation, they cannot specify which session to use for the conversation, but they can specify what the characteristics of the session are. Transaction programs specify these characteristics by the mode name. Mode names are assigned by the system administrator.

All sessions between a pair of LUs that have the same mode name are called session groups. These sessions form a group that can be treated as a pool of sessions sharing the mode name characteristics. Programs can control the size of the pool, but the LU is responsible for actually handling the individual sessions that make it up.

LUs can define several different session groups for sessions with another LU. Thus, an LU could have a FILESERV mode name defined for sessions with a partner LU used by file-server programs, and other mode names such as INTERACT defined for sessions with the same LU used for database queries. In this example, FILESERV could denote sessions with a large request size, which would aid bulk transmission of data.