dns server config (no internet = no phones)

[edisoninfo]

I know this topic has been beat to death but I can not get it working still. I have researched and tried all the solutions I've found and it still craps out. I can not set srvlookup=no since I have several voip trunks and they fail to register. I have my own dns servers and the piaf box is pointed to it but that does not help either. I know there must be a work around so the box can function with the TDM pstn trunks even tho there is no internet. Am I fighting a dns server config issue or an asterisk config issue? I realize it is a bug of sorts, but there has to be a way around it.

 

[gregc]

What we have done is to only use SIP providers that provide IP address authentication. With this method, we do not register with the provider so asterisk doesn't know if there is a lack of registration due to whatever cause.

-Greg

 

[edisoninfo]

What we have done is to only use SIP providers that provide IP address authentication. With this method, we do not register with the provider so asterisk doesn't know if there is a lack of registration due to whatever cause.

-Greg

Hm, is that the root of the problem? When asterisk tries to register via a dns lookup and fails, it locks things up continually trying? So when the phones do their "register" thing asterisk is not paying any attention?

I have my own dns server so it "should" be caching the IP's of the voip providers I would think. I will try to change to IP addresses and get rid of dns lookups. First I think I will try hard coding the IP's into the dns server and see what happens. I hate to turn off the lookups since the dial by url will not work anymore either. Hmm...

 

[gregc]

I am not sure of how it all works or why, but from what I gather, the bottom line is when a SIP trunk (maybe others?) registration fails, so does the rest of the SIP connections. To battle the problem in the early days, we simply used IAX trunks, which works fine even today. Many providers don't provide IAX connectivity or offer no support for it. But many are starting to provide IP authentication which is a very nice alternative.

We just whitelist our providers' IPs in our firewall and route them to the PBX. Works great... as long as they don't change their IP.

-Greg

 

[blanchae]

Do you have your dhcp pointing to your caching dns server?

 

[edisoninfo]

Do you have your dhcp pointing to your caching dns server?

Yes I do.... (extra periods to get over 10 characters so I can post a reply!)

 

[blanchae]

I've found it very difficult to configure sendmail as it comes with PiaF to be a caching DNS server. Last month, I came across ClearOS - Centos based enterprise level server distribution that has a fantastic caching DNS server that is incredibly easy to set up. I just haven't had the time to see what they are using for the back end. Just another project to add to the list...

 

[jmullinix]

This is off topic, but ClearOS works swimmingly as a Windows Domain controller and file server too.

 

[blanchae]

This is off topic, but ClearOS works swimmingly as a Windows Domain controller and file server too.

And ftp, web and DHCP server...

 

[Stewart]

The actual problem is the inability to resolve the names of your providers in your trunks, not the inability to register. For example, lets say your provider is trunk.provider.net. If you edit your /etc/hosts file and statically add their IP to trunk.provider.net (so it reads something like "111.111.111.111 trunk.provider.net"), your problems will go away, you just wont be able to make outside calls. Aastra phones present this as "No Service" when they lose registration due to this "feature". All of our clients whose trunks use names and not IPs have the hosts file containing all the info. Fixes it right up.

We also use dnsmasq and that helps with a whole host of other issues that may pop up.