[Asterisk-Users] ZyXEL Router Terrible Voice Quality

[Aza]

On Sun, 17 Apr 2005, Dave Weis wrote:

> On Sun, 17 Apr 2005, Greg Boehnlein wrote:
> > On Thu, 14 Apr 2005, Rod Bacon wrote:
> > 
> > > I have been frustrated by a variety of zyxel issues/products and have
found 
> > > the best solution for all of them lies in a cylindrical receptacle
that sits 
> > > beside my desk...
> > 
> > I've had pretty good luck with the Zoom X5V Voice Modem so far. It has a

> > built in DSL modem, and a single FXS port. Decent little router, now
that 
> > the latest firmware is out, but tcp and udp timeouts through NAT seem to

> > be set a little low, so I lose SSH sessions.
> 
> I bought a dozen and have had bad luck with them. I couldn't keep an ssh 
> session for more than 15 seconds. Trying to update firmware turned two of 
> them into paperweights. I couldn't get the FXS to ever register.
> 
> Other than that, it looked like a good idea. Is the NAT timeout 
> configurable now?

>Not sure. I'm unable to open a ticket with Zoom technical support on the 
>issue.

I seem to have found a solution to the problem I had with a ZyXEL Prestige
2000 series ATA. It looks like these things just can't cope with NAT no
matter what you do with Asterisk, STUN servers or SIP Proxies. Specifically
the voice quality of the person speaking through the ZyXEL is more chopped
up then a diced onion if you're going through NAT.

I found two solutions, the first one was to put the thing a public IP
address and eliminate NAT altogether. Voice quality was then very good.

The second solution that seems to work is to port forward on your NAT
directly to the ZyXEL. I forwarded ports 5060 and 50,000 to 65,535 (the
range the ZyXEL insists on) and then on the ZyXEL enabled the "Use NAT"
option and put in the public IP address of the NAT. On Asterisk I just left
everything as for any other device behind NAT. This also seems to produce
good quality calls. 

It's a lot of jumping through hoops for something every other device seems
to have no problems with! Hopefully someone from ZyXEL reads this.
Interestingly the first thing the ZyXEL tech support wanted to know about
was NAT even though I told him the calls were getting through...

Aaron