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Standard User jpm
(member) Tue 08-Dec-20 10:47:58
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Re: Incoming VOIP call drops every 15 minutes


[re: farrinaf] [link to this post]
 
Hard to tell as the capture doesn't have the SIP messaging in, not sure if that was filtered out or if it just wasn't appearing.

Is there something called NAT refresh time in the Gigaset settings?
Standard User farrinaf
(newbie) Tue 08-Dec-20 12:11:26
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Re: Incoming VOIP call drops every 15 minutes


[re: jpm] [link to this post]
 
Thank you for your interest (and prompt attention).

I have reviewed the Gigaset configuration screens but can see no mention of anything NAT related.

It is strange that there is no SIP traffic showing in my original trace. As I am not immediately in a position to undertake a further "Talk Talk" capture, by way of an experiment I tried ringing my VOIP landline from my mobile whilst initiating a capture in the form previously advised.

This later capture clearly shows a SIP/SDP invite request with my mobile number and AAISP VOIP user name visible, as well as the disconnect instruction upon termination, so it would appear to be correctly configured.

I think the only logical way forward it to once again try a "new" capture, this time with a longer pre/post capture period (unfortunately with inevitable further delay)

Edited by farrinaf (Tue 08-Dec-20 12:12:16)

Standard User kitcat
(experienced) Tue 08-Dec-20 14:38:40
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Re: Incoming VOIP call drops every 15 minutes


[re: farrinaf] [link to this post]
 
farrinaf

On your mobile calls you should see at the start a SP invite and an ack, etc.

It sounds like on talktalk one That the call is just dropping at the talktalk end with no SP cleardown.

If you get the trace at the start it may show that TalkTalk is not ack the SIP setup so it just times out at 15 min and drops the call ( not a call disconnect). The 15min is just the set time if it doesn't see a response.

It can also be that the TDM-IP gateway somewhere has not been setup correctly to pass the correct C7 signal back to the TDM which will lead the TDM switch to time the call out after the set period (15 min) . In which case the SIP will again not show anything for the disconnect..

I believe the 2nd is the most likely BUT this makes it almost impossible to put right unless you know a technical person dealing with the TDM-SIP gateways that TalkTalk are passing through.

(We used to see the max call length truncated from what would be expected if something like this had happened BUT had to be looking at each gateway to be aware of it and only a nerd like me ever looked to see why different gateways had different call characteristics.)
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Standard User farrinaf
(newbie) Thu 10-Dec-20 14:34:01
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Re: Incoming VOIP call drops every 15 minutes


[re: kitcat] [link to this post]
 
In reply to a post by kitcat:
farrinaf

It sounds like on talktalk one That the call is just dropping at the talktalk end with no SP cleardown.

If you get the trace at the start it may show that TalkTalk is not ack the SIP setup so it just times out at 15 min and drops the call ( not a call disconnect). The 15min is just the set time if it doesn't see a response.

Thanks for the input - I shall, as per your suggestion, arrange to packet capture the start of the call.

My "Talk Talk" subscriber is not a frequent caller (he's a 91 year old friend, so I have to go at his pace not mine!) so there may be a further delay before I come back to the forum.

Cheers

Edited by farrinaf (Thu 10-Dec-20 14:34:28)

Standard User farrinaf
(newbie) Sat 19-Dec-20 16:19:45
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Re: Incoming VOIP call drops every 15 minutes


[re: farrinaf] [link to this post]
 
Okay I now have a packet capture I initiated (by prior arrangement) a couple of seconds prior to my friend initiating a call to my VOIP line from his Talk Talk land line with my capture terminating shortly thereafter.

I have also taken the opportunity to freshly capture what happened at 15 minutes (not same segment as initiation capture) when the call apparently drops.

Packet capture an be viewed on Google Drive here

His line is Ex Directory so his telephone number is not shown (although my test VOIP line number is!).

As far as I can ascertain beyond my test VOIP number there is no other particularly confidential information disclosed - if anyone spots anything buried within the data that may be, I would be obliged if they would let me known and I shall remove the capture from public view and make it available upon request on a named basis.

Looking at the actual data I believe I can see a SIP ACK at line 16 but this seems to be coming from AAISP (81.187.38.118) – I wonder if I need to chase them to see if their logs shown anything back to Talk Talk.

I suppose the other unknown (to me at least) is how Talk Talk calls are routed to AAISP
Standard User kitcat
(experienced) Sat 19-Dec-20 20:41:12
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Re: Incoming VOIP call drops every 15 minutes


[re: farrinaf] [link to this post]
 
farrinaf
Initiation
The Ack is on line 84.CSeq: 1 ACK

Line 2066 sets a timer expiry of 600 seconds this should repeat every 10 600 sec. ( 2052 offers 180 seconds)

15 min term

has another expiry of 600 seconds on line 71

Note on line 56 the other end keeps offering 180 sec

I can see no BYE in either file ( there is a bye in the initiation file at line 2073 but not a SIP message.)

five 180 offers would be your 15 min. Just wondering if TT end is not recognising your 600 second response

I still think the TalkTalk end is tearing it down without sending a BYE due to a timeout somewhere.

Simple SIP tutorial but doesn't cover this variant very well.
Standard User farrinaf
(newbie) Mon 21-Dec-20 09:40:40
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Re: Incoming VOIP call drops every 15 minutes


[re: kitcat] [link to this post]
 
Kitcat

Thanks for taking the time to respond (so promptly as well) and for the further information therein.

Will investigate further and review the article you kindly linked to.

Cheers
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