Bandwidth Management

I have a Cisco 831 router at home. I have two PCs and a VOIP
phone (HandyTone-286) plugged into the router.

I am having some problems when calling Australia. As an old
MCI central office person, my first instinct is that there is a
problem on the VOIP provider's network which processes Australian
calls (or one of the companies that they interface with). One number
in Australia that I call, they can never hear me. Another one works
fine. This morning, yet another one (that I previously called and had
a good conversation with good results) answered and couldn't hear me
again.

When I connect to U. S. numbers, I can generally speak
to them and they can hear me. The only problem I am experiencing in
the United States is calls being processed through (sometimes, I have
to hang up and dial again). When I get through, we talk quite fine.

I discussed it with the VOIP provider this morning. He is
pointing at my Cisco router saying it would be a function of what kind
of NAT I was running. But he couldn't expand upon that. He said he
was Cisco trained, but he couldn't tell me what to look for in the
Cisco IOS. He said I'd have to take it up with Cisco. He said the
customers experienced this all the time and he couldn't keep up with
how to fix it in so many different makes of routers. I pointed out
that the majority of his customers would probably have Cisco and that
they should know how to configure a Cisco router through the IOS to
fix this problem. He left it between me and Cisco none the less. He
couldn't tell me where to look in the setup to find what he wanted to
know nor could he tell me exactly what I was supposed to find. All he
said was to find out 'what kind of NAT I was running'.

My reaction to that was shock. In all my years in the telecom
industry, I've never know my company to leave a customer hanging like
that.

Can anyone enlighten me as to specifically what I might be
looking for in the configuration of my 831? I've got a feeling that
this is an exercise in futility, but maybe we'll learn something here.



Fred

 

I wouldn't know what setting to tweak the c831, but do know that VoIP
requires a high QoS. Since you hace an 831, I can only assume you are using
ISDN or DSL. If you are not using a tier 1 service provider, the multiple
hop count and "poor" peering could be the cause of the issue. Not to mention
that long trans-pacific route. Try a traceroute to your destination in
Australia in which you get good calls and compare it it a traceroute to the
one whom can't hear you at all. Compare the latency.
Hope this helps.

 

I think I must agree fully with Chad: to make voice work well, you need a
high QoS. This is probably the singlemost biggest factor for the slow
take-off of VOIP (they were saying "its the year of VOIP" about 5 to 10
years ago, and we're STILL waiting!).

The problem (in your case) is not likely to be at your router, as you'll not
be doing much else whjen using the VOIP (ie there's no competing traffic on
your access pipe).... but across the internet, on trans-pacific links, there
will certainly be plenty of other traffic to get in the way to add latency /
lose data.... and it will, of course, depend on which routing your VOIP data
takes. Some (remote) providers will have better links, others will have
worse.

That explains well why, within the US your VIOP runs well, but is
problematic with Australia.

In the professional market, the customer will end up paying a lot of extra
money to ensure Quality of Service for VOIP: they will use PacketShapers (or
queuing on routers) to ensure that VOIP has priority on the access pipes,
and will pay for "Gold service" within MPLS routed networks.

As far as what the guy at your ISP says: unless you pay extra to be with one
of the more "professional" internet providers, then (in most cases) given
the peanuts they get paid, don't expect more than slightly trained monkeys
to sort out your tech calls. These guys can probably cope with modems on a
PC, but they will have little or no practical experience of routers.


Paul