[Spce-user] correct NAT configuration

Jon Bonilla (Manwe) jbonilla at sipwise.com
Fri Dec 28 08:34:05 EST 2012

El Fri, 28 Dec 2012 14:22:27 +0100
"Joan Cifre (ibred)" <jcifre at ib-red.com> escribió:

> Hello all,
> we are experiencing many issues regarding to NAT with our SIP 
> registration. Our phones register correctly, but if public IP changes, 
> the phones failed to register again. We have noted it after a problem 
> with DHCP that changed may of the public IPs of our customers routers.
> I'm sure it can be optimized and probably our configuration of phones 
> and routers is not optimal. The first we can observe is that in the 
> Sipwise administration interface, in the registration of the phone, we 
> are getting "NAT: no" in all registrations.
> User Agent: Grandstream HT701
> Contact sip:n971520810 at
> NAT no
> Expires2012-12-22 03:52:39
> But in fact phones are behind NAT (they have private IP address). Our 
> routers have NAT helpers with SIP ports configured (5060, 5061). And 
> also our phones have NAT mapping enable set to yes, but no STUN server 
> configured. Is there a better configuration than this one? Maybe Sipwise 
> could handle the NAT itself? As I told the problem is when the public IP 
> changes.

Yes, the provider can handle NAT for endpoints. 

Usually, NAT helpers (SIP ALG) in routers break SIP traffic and it's more a
problem than a solution. I would disable every kind of stun configuration and
NAT helpers and let the spce handle the nat of your devices.

It's not the only solution, just one solution.

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