I am developing an Android SIP client. I'd like to test it against OfficeSip server. So I have set up the officeSip server locally and I can connect to it via officeSIP messenger (the client).
The messenger requires this data to login:
public SipProfile.Builder (String username, String serverDomain)
public SipProfile.Builder setOutboundProxy (String outboundProxy)
Turns out, Android SIP stack is quite immature and finnicky.
Ultimately I was able to connect by specifying both server hostname and server proxy. Also, if server domain differs from computer name server is running on, you WILL have issues connecting. Domain must match either IP address or computer name, but they must match in order to connect via Android SIP client.