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

[Jared Mauch <jared () puck nether net>]

On Nov 9, 2011, at 2:45 PM, Jeff Wheeler wrote:

> On Wed, Nov 9, 2011 at 1:47 PM, Jay Nakamura <zeusdadog () gmail com> wrote:
> > 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
>
> I ran into exactly this problem last week with Rogers.  All traffic
> from the client except udp/5060 could be received by us, and udp/5060
> was blocked.  We tested other IP addresses on our (provider) side and
> did not find any blocking there, so we assigned a new IP to the SIP
> gateway.  I hardly think this can be an ordinary malfunction, but good
> luck getting a phone company to troubleshoot a problem with their
> subscribers using mobile data to connect to a third-party voice
> gateway…

I've seen UDP/5060 be intercepted or blocked by various providers.  This
is common in international markets.  If you are doing VoIP over the public
internet, it may be worthwhile to invest in software or hardware that
can VPN either 'back' or 'out' to the internet.  I have a PPTP VPN
solution I use to escape various hotel networks.  You can even do an
install on a Linux box with the poptop/pptpd solution.  (Having a
ssh server on tcp/80 and tcp/443 also can help, and is part of 'being
prepared').

- Jared