An invoking TP can be located on any system on the SNA network. An invoking TP identifies itself by issuing Initialize_Conversation, which specifies the name of the invoking TP and the symbolic destination name to be used. A local LU alias can be specified for the invoking TP by using a registry or environment variable, as shown in the following table.
| Operating system on computer that contains invoking TP | Location and name of variable |
|---|---|
| Microsoft® Windows NT® | Location in Windows NT registry:
HKEY_LOCAL_MACHINE
Variable:
|
| Microsoft® Windows® 95 | Location in Windows 95 registry:
HKEY_LOCAL_MACHINE
Variable:
|
| Windows version 3.x | Section and variable in WIN.INI file:
[ApplicationName]
|
| OS/2 | Section and variable in SNA.INI file:
[ApplicationName] |
If the local LU alias is not specified in a registry or environment variable, SNA Server must be configured to supply it through one of two types of default local LU; otherwise, Initialize_Conversation will fail. For more information, see Invoking TPs and the SNA Server Configuration.
Next, the symbolic destination name specified in Initialize_Conversation provides the name of the invokable (or partner) TP and the partner LU alias (the LU alias to be used by the invokable TP). With this information available, the invoking TP can issue the Allocate call.
After a TP successfully issues an Allocate call, an allocation request flows. For more information about what happens after an invoking TP requests an invokable TP, see Matching Invoking and Invokable TPs.