[asterisk-ss7] Some sessions hangs. Is it possible with SS7

Anton anton.vazir at gmail.com
Fri May 12 21:47:07 MST 2006

Hi Darren,

Thank you for advice!

If you could help me with a little more info on that issue:
In the calls Ie given below there is the same mobile 
subscriber calling the same destination in 3x overlapping 
sessions. Destinations are Afghanistan, so there are old 
stupid analogue PSTN, that may not release the call.
So clearly he cannot do it himself, and either Erricson AXE 
10 switch did not send RELEASE, or Asterisk have not 
received it, or just did not handle it. But as the result - 
there are sessions which can last forever, or while some 
party in the middle would time it out. Do you have any idea 
of avoiding such cases? Is there are some sort of SS7 
messagers to syncronyze the CIC states periodically?

Thanks in advance,

On 13 May 2006 04:01, Storer, Darren wrote:
> Hi Anton,
> the state of CICs can become unsynchronised between SS7
> nodes although it doesn't happen too often. Sometimes
> Node A thinks that a particular CIC is "In Service Free"
> whilst Node B thinks that Node A didn't handle the last
> call correctly and places the same CIC into a blocked
> state at a higher application layer.
> When this situation occurs we normally use MML to "flex"
> the CICs by manually taking each suspect CIC out of
> service and then returning it back to service. I have
> seen that chan_ss7 appears to support these maintenance
> messages but I haven't used them myself.
> When an SS7 node is started for the first time (cold
> start) it has no knowledge of the state of the CICs as
> maintained by another SS7 node that it is connected to.
> To synchronise the state of the CICs after a cold start
> it is common to see many block and unblock messages
> (including Circuit Group Resets) after the signalling
> links are aligned but before the route starts to handle
> live traffic.
> Regards
> Darren
> On 12/05/06, Anton <anton.vazir at gmail.com> wrote:
> > Guys,
> >
> > Does anyone know, if it is possible for timeslots to
> > hang, with SS7 signalling?
> > For example if REL message is missing (did not received
> > in time by Asterisk) -
> > would the accured timeslot hang (be active on Asterisk
> > side, but released in the TELCO side?) I've strange
> > issues with one of my telco's. The sessions just timed
> > out, and released by the Asterisk itself, since there
> > is 3600s duration limit.
> >
> > Any help is highly appreciated!
> >
> > ,"SS7/15","IAX2/axsoftsw1-16389","Hangup","","2006-04-2
> >1 23:04:54","2006-04-21 23:05:00","2006-04-22
> > 00:04:59",3605,3599,"ANSWERED","DOCUMENTATION"
> > ,"SS7/19","IAX2/axsoftsw1-16392","Hangup","","2006-04-2
> >1 23:05:23","2006-04-21 23:05:29","2006-04-22
> > 00:05:28",3605,3599,"ANSWERED","DOCUMENTATION"
> > ,"SS7/11","IAX2/axsoftsw1-16393","Hangup","","2006-04-2
> >1 23:46:00","2006-04-21 23:46:07","2006-04-22
> > 00:46:07",3607,3600,"ANSWERED","DOCUMENTATION"
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