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

[Jay Nakamura <zeusdadog () gmail com>]

It started sometime Tuesday morning.  I have yet to set the route back
to Qwest.  I am going to do that tonight and test it.

On Wed, Nov 9, 2011 at 2:04 PM, Preston Parcell
<preston.parcell () viawest com> wrote:
> 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.