[Sipsak] Query ,How to senf NOTIFY

[tanzeel sarfaraz]

Hi users ;

i m new in mailing list and also to use in sipsak.
i have to implement scenario of MWI like this: 
http://lists.iptel.org/pipermail/serusers/2004-September/011552.html

<asterisk>---<openser>

sipsak run on the same machine where asterisk run .
openser is on another machine.
My question is :

Q:what is the command to send the NOTIFY request for MWI ?

Regards;
tanzeel