Configuring Systems for Terminals, Printers, and Other Serial Devices (32022-90057)

Describing Asynchronous Devices
How to Access Multisessions
Chapter 9
168
How to Access Multisessions
Multisession is the ability to have a device on a DTC simultaneously associated with
multiple sessions, jobs, or processes on one or more hosts.
Each port can support up to 5 connections and connections can only be active one at a
time; the other connections are in a “hold” state. The connection establishment method
(Session or Programmatic, that is, FOPEN) for multiple connections associated with a
particular port is determined by the first established connection. If this is a session then
the other multisession connections to that port must be session. Similarly, if the first
connection is established through the use of a programmatic process, the other
multisession connections must be established through the use of a programmatic
process.
Multisession is only available in a PC-based network environment (that is, when the
DTCs are managed by an OpenView Windows Workstation on the LAN).
Multisession is supported on switched ports only and some restrictions apply to nailed
devices. See the list below:
• Switched Ports: Multisession is supported only for switched ports.
• Non Switched Ports: The DTC User Interface is not accessible to non switched
ports. For Multisession to establish another connection it needs the DTC User
Interface.
• Nailed LDEV: If a switched port is configured as a nailed LDEV on a system, then
multiple sessions from that port to that system are not possible because the port can
have only the one connection associated with the assigned LDEV on the host system.
Although multiple sessions to that particular host are not possible, it is possible to
establish multiple sessions from that switched port to other systems.
• Non Nailed LDEV: If a switched port is configured as a non nailed LDEV on a
system, then multiple sessions from that port to that system are supported in
addition to multiple sessions to multiple systems.