Q: how do I test a Java SIP client? SIP programming looks much simpler than I originally thought:
http://www.javaworld.com/article/2071781/java-web-development/sip-programming-for-the-java-developer.html
and
http://docs.oracle.com/cd/E13209_01/wlcp/wlss40/javadoc/jsr289/javax/servlet/sip/SipServlet.html
I would be interested in developing something along the lines of the Java World sample, but how do you test it?  I would like to test it against a hosted Asterisk PBX, but that seems expensive.
The only other option I can think of would be to deploy Asterisk, but that doesn't sound like much fun.
While I'm aware that there is, or will be, a Java API for the Asterisk Manager Interface, I'm interested in just plain-vanilla SIP.

A: 
how do I test a Java SIP client?



*

*If you have a SIP server in place then you try to register your
client to the server by sending a SIP REGISTER message.

*If you don't have a SIP server in place, then use SIPServlet to
create a basic server with at least a doRegister implementation. Once
you have that, you can test a client with registration process.

*If you don't have both a client and a server. Then write a basic
server using SIPServelt. You can use any SIP client(SIP soft phone)
downloaded from internet to test your server.


Your questions is not very clear, hence I have provided the answer for different situations.
