Re: Anyone seen this kind of problem? SIP traffic not getting to destination but traceroute does

[Owen Roth <owen () impulse net>]

Yes!

Yesterday, from 9AM-10AM PST, I had a Qwest client transiting Level3 where traceroutes were working, but sip 
registrations were not. They were leaving fine, but not being received on the destination side. 

Then at 10AM-2PM PST, same client, registrations and invites were now working, but "180 RINGING" was being eaten. 
Things worked fully at 2PM. We only contacted Level3, and they didn't see any issues at around 1:45PM PST.

Regards,
Owen

----- Original Message -----
From: "Preston Parcell" <preston.parcell () viawest com>
To: "Sean Harlow" <sean () seanharlow info>, "Jay Nakamura" <zeusdadog () gmail com>
Cc: "NANOG" <nanog () nanog org>
Sent: Wednesday, November 9, 2011 11:04:01 AM
Subject: RE: Anyone seen this kind of problem? SIP traffic not getting to destination but traceroute does

What was the timeframe for your issues? Just curious since we saw some strangeness last night.


Preston 



-----Original Message-----
From: Sean Harlow [mailto:sean () seanharlow info] 
Sent: Wednesday, November 09, 2011 12:00 PM
To: Jay Nakamura
Cc: NANOG
Subject: Re: Anyone seen this kind of problem? SIP traffic not getting to destination but traceroute does

I can't say I have a specific answer to your question, but yesterday I was seeing major packet loss on outbound audio 
from all my VoIP customers using Qwest and going in to servers on L3.  It's entirely possible that SIP was also being 
lost, just the audio was the more notable and pressing issue.  It seems to be resolved at this point, but we have not 
yet heard from Qwest what the actual problem was.

This was with sites in Northeast Ohio and the Chicago area connecting to servers in New York and LA for what it's worth.
----------
Sean Harlow
sean () seanharlow info

On Nov 9, 2011, at 1:47 PM, Jay Nakamura wrote:

> We ran into a strange situation yesterday that I am still trying to 
> figure out.  We have many VoIP customers but yesterday suddenly select 
> few of them couldn't reach the SIP provider's network from our 
> network.
>
> I could traceroute to the SIP providers server from the affected 
> clients' IP just fine.  I confirmed that the SIP traffic was leaving 
> our network out the interface to the upstream provider and the SIP 
> provider says they couldn't see the SIP traffic come into their border 
> router.
>
> SIP traffic coming from SIP provider to the affected customer came 
> through fine.  It's just Us -> SIP server was a problem.
>
> I thought there may be some strange BGP issue going on but we had 
> other customers within the same /24 as the affected customers and they 
> were connecting fine.
>
> The traffic at the time traversed
>
> Our network -> Qwest/century link -> Level 3 -> SIP provider
>
> I changed the routing around so it would go through our other 
> upstream, AT&T, and it started working.  With AT&T, the route was
>
> Our network -> AT&T -> Level 3 -> SIP provider
>
> So my questions is, is it possible there is some kind of filter at 
> Qwest or Level 3 that is dropping traffic only for udp 5060 for select 
> few IPs?  That's the only explanation I can come up with other than 
> the whole Juniper BGP issue 2 days ago left something in between in a 
> strange state?  I read the post about XO doing filtering on transit 
> traffic, I haven't seen anyone say Level 3 or Qwest is doing the same.