2talk SIP registration delays

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nicmair

244 posts

Master Geek

#303305 31-Jan-2023 09:41

Hi, we have (about 116 of them) SIP accounts that register from our SIP servers to 2talk. For years everything has work perfectly, however recently (or maybe as late as Oct/Nov last year) we have had reports of random call disconnects, where calls are being cut off mid conversation. The only clue we have, is that for each account, (phone number) it has to register with 2talk, a process that normally takes <30ms, but now we are seeing registrations taking over 3000ms. As the SIP server see’s any registration over 2000ms as to laggy to maintain a call, once an account registration goes over 2000, if a call is in progress, it will be disconnected.

This picture shows what we see when we check the SIP registrations. This is a snapshot view, and when we refresh this snapshot, the lagged one could be fine, but another one (or in most cases another 4 or 5) will be in red.

While I have no records, I pretty sure that when things where okay, an OK registration was <40ms, so even the 112/134ms if higher than we have previously seen.

What’s even stranger, is that we setup some accounts/numbers on another provider, and these are well with the normal range and function fine.

The onsite(s) phones (about 250 of them) registrations to the SIP servers are fine, on average being <15ms. Its only the 2talk registrations that are the issue.

If we ping/tracert from any device on the network, we get response times of <20ms to the 2talk address (27.111.14.65). Our SIP server actually uses a host name of sip.2talk.co.nz, but even if I change this to the IP to eliminate any DNS, there is no difference in SIP registration times, and ping/tracert to either address see the same results.

We have 2 SIP servers at different locations, and both are experiencing the issue, (The SIP servers are reskinned, 3party supported Asterisk based SIP servers).

Our network routers and firewall are provided as part of a managed service from a very reputable provider, and we are experiencing no other network related issues, but I have had them check every bit of the network, checking every log(s), doing traces etc etc and they can’t see any delays or issues with getting to 2talk. Firewall logs and traffic monitoring also shows no blocking going on. When we do packet captures, all we see when a call disconnects mid conversation (although frustratingly as the laggy is so random, it takes quite some planning/luck to capture/spot a failed call…), is a call disconnect signal, exactly what we see for normal calls.

We have logged support calls with 2talk where they ask for dates/times of disconnected calls, which have not yielded any insight into where the issue might be. I doubt it’s a 2talk issue, as I would have expected a lot more noise from the community. Our SIP server support folk have been all over the SIP servers, and there has been no updates or changes, and when checking with their other clients with the same SIP server and accounts with 2talk, they aren’t’ seeing the same registration delays.

I’m stumped, and while we can move our SIP trunks to another provider, (and likely will just to restore stable voice calls), I’d love to get to the bottom of this, so any suggestion folks might have would be greatly appreciated.

Ta.

speed

293 posts

Ultimate Geek

#3029872 31-Jan-2023 09:48

Registration problems shouldn't ever affect live active calls. You should be able to make outbound calls without any registration working at all. Registration is a process through which the client ensures the server knows the current path through which to reach it for the purposes of sending new INVITEs.

That's not to say SIP registration problems with 2talk aren't a real thing - they are, and they can be caused my many different issues. But they should not make active calls drop. I suspect both are in fact symptoms of a differing underlying root cause.

I wish you the very best in diagnosing it, but I hope you don't spend too much time on the red herring :)

speed

293 posts

Ultimate Geek

#3029914 31-Jan-2023 11:57

PS, I recommend you have 2talk terminate one of their own broadband connections directly into the premises at one of your SIP servers in parallel with your existing connection. If your sites are on UFB fibre then this can be done very economically (ie just for the cost of one month's connection). You then route the SIP traffic directly to 2talk over that dedicated link. I have a feeling that in doing so you'll see both problems disappear and be a step closer to final resolution. If I'm wrong then you just disconnect the link and it only cost a month's access fee.

I do realise you've already had your network provider all over it, but there's little they can do if it's congestion on 2talk's own peering links (which you can bypass with your own circuit directly into their network). Plus I've experienced very similar issues multiple times with them over the decade or so that I helped run an ITSP service. I'm very familiar with seeing those lagged connection output reports from Asterisk :) FWIW, ee ended up getting a direct cross-connect patch into 2Talk's network at 220 Queen and from that point forward things were far more stable.