Brian West wrote:
On Apr 6, 2008, at 5:33 PM, kokoska rokoska wrote:
Thank you very much, Brian, for super tip!
I know I can append headers (yout wrote it to me few days ago :-), but I didn't know how to modify replies. And if config above will work, it is exactly what I need.
BTW: Is there a way how to get contents of SIP headers on incoming INVITEs? (I'm wondering especially on standard "Diversion" header - parameters "reason" and "counter" - and nonstandard but widely used "X-HopCounter" header.) Do you have any hints here?
Isn't this what Max-Forwards header is for? Inbound Diversion is sip_h_diversion variable.
Thanks Brian for your answer! I will look at sip_h_diversion to know how "reason" and "counter" is converted (one string I'm afraid).
We already kill the call if the Max-Forwards makes it to zero.
No, unfotunately, Max-Forwards is not for the same thing. X-HopCounter we (I and lot of VoIP providers around me) use for overall "hops" (visited call-routers) counting - ISUP and SIP. This variable comes from SS7 world (ISUP) and is mandatory for good interconnection (helps against loops etc. - similary as MaxForwards does) especialy if RNPDB comes into the game :-) First router sets HopCounter to 31, every next router should decrement the value on every single processing attempt (i.e. if call goes thru 5 extensions in Freeswitch dialplan it should be decremented by 5) and on 0 or lower values router should stop routing and reject the call... Thanks again for your help, regards kokoska.rokoska