[Freeswitch-dev] call forward howto
mike at jerris.com
Mon Apr 7 07:51:37 EDT 2008
On Apr 7, 2008, at 3:45 AM, kokoska rokoska wrote:
>> 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
> "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
> 0 or lower values router should stop routing and reject the call...
I think we would probably convert this to a Max-Forwards when doing a
sip interconnect, I need to see if we decrement it in a transfer
within the switch, I believe we already do. But like all the other
headers, we can get it with variables, and create the other header,
but we only auto decrement the Max-Forwards. That being said, it is
not required that we start Max-Forwards at 70. I have in the past
passed this along from ss7 by either passing the value directly from
ss7 or using a ratio calculation similar to how cisco does it.
More information about the Freeswitch-dev