Keep in mind the remote side might not always send a 200 OK. Some send 404, 501, 503, etc. When pinging a gateway (I believe) FS treats all of them the same. As long as *something* comes back the gw is marked "up". On some software (OpenSIPS with various gw modules, etc) this behavior is configurable. Not sure about FS. On Fri, Feb 26, 2010 at 7:52 AM, Steven Ayre <steveayre@gmail.com> wrote:
A SIP 'ping' is not a ICMP ping...
It works by sending a OPTIONS SIP request to the gateway, which then responds with 200 OK. It has the advantage of working even if ICMP is filtered by a firewall and testing whether the SIP server software is running, not just whether the server is online.
Best Regards, -Steve
-- Kristian Kielhofner http://www.astlinux.org http://blog.krisk.org http://www.star2star.com http://www.submityoursip.com http://www.voalte.com