REFER method- JAIN SIP API - JAVA- Call transfer

Question

Could you please give a idea of how to use REFER method in JAIN SIP API in java. I would like to use REFER method because i would to use call transfer.

Answer 1

If you already established a SIP dialog it's pretty simple:

public void sendRefer(String to, String by) throws Exception, SipException {
    Request req = dialog.createRequest("REFER");
    req.addHeader(headerFactory.createHeader("Refer-To", "sip:"+to+"@"+realm));
    req.addHeader(headerFactory.createHeader("Referred-By", "sip:"+by+"@"+realm));
    dialog.sendRequest(provider.getNewClientTransaction(req));
}

If you are dialog-stateless it's a bit more complicated and it you will have to build it as a subsequent request.