What are you actually looking for ? SIR in Nokia WAP gateway (NAWG) means Subscriber Identification Resolver. Perhaps you are interested for sending WAP push messages. Please study the following document: WAPpushInfoPage_v1_0.pdf document on the Forum Nokia site (www.forum.nokia.com) for sending WAP push messages .
Antti / Forum Nokia
RE: how to send a SIR(Session Initiation Request).