calling a sip phone

Question

im searching for a simple method to "ping" a sip:user@ip and get back a status like "available for call" , "busy" , "not connected" if the first two require to make his phone ring, thats ok (optionally if necessary to call them to see the status then it was nice to include a senders number so that i can identify my server on the phone display when its checking the status or to play a short signal .wav in case someone takes up, so that they know what it was)

.....something like sipsak -x 1200 -C random@ownip -s sip:adressee@hisip -vvv...
gives me "406 Not Acceptable without Contact header" i did not try anything else yet i already wonder if the sending call still needs to be logged in at an isp then?

Answer 1

You're probably looking for the OPTIONS message. The reply to an OPTIONS does two things - first, it tells you the capabilities of the remote party and second, more importantly, the Status-Code returned is the Status-Code you would get if you'd sent an INVITE.

According to sipsak's documentation you're looking for this:

sipsak -vv -s sip:[email protected]

Answer 2

SIMPLE will work, but it may be overkill for what you want to do. See http://en.wikipedia.org/wiki/SIMPLE

Of course, not all SIP phones support SIMPLE.