The configuration information for a Microsoft® SNA Server system is stored in two forms:
An SNA Server SNALink is defined when an SNA Server system is installed. An SNALink can support only one physical connection from the server. If a single adapter is capable of supporting multiple physical connections, SNA Server requires multiple SNALinks to be configured.
To reconfigure a server's SNALink support (for example, after installing a new adapter), the administrator uses either the Windows NT or Windows 95 Network Control Panel applet or the SNA Server setup program. For further details of how this operates, refer to Setup Information.
All other configuration of an SNA Server system is performed using SNA Server Manager. Refer to the Microsoft SNA Server Reference for further details. As part of the configuration process, logical connections to remote PUs are associated with one or more SNALinks.
All configured SNALinks are automatically started when the SNA Server system is started. At this stage, the SNALink performs any initialization required and then waits for instructions from local nodes.
When a connection is activated, either from SNA Server Manager or automatically (for example, in response to a 3270 user's request for a session with a remote host), the SNALink receives an Open(LINK) message from the local node. The SNALink should then perform whatever action is required to initiate that connection. This can involve dialing a telephone number for a switched Synchronous Data Link Control (SDLC) connection or bringing up level 2 on an X.25 link and sending a CALL packet.
If the IHV wants the same physical adapter to be available for use by multiple SNALinks (for example, a dumb SDLC card can be used to communicate using SDLC or X.25 protocols), the SNALink should not attempt to access the hardware until it has received an Open(LINK) message from the local node.