Issue with call drops at 15 minutes SIP update

[bigdessert]

I am using an unsupported provider and am having a random issue. When making calls to specific numbers that go to upstream CLEC at the 15 minute mark the call will drop. I have worked with the provider and what looks to be happening is they have a DNS A name set for the registration that round robin DNS load balances. So the call initiates with IP A and then at 15 minutes 3CX sends an update but it re-resolves the DNS A name and then the update gets sent to IP B. This then drops the call because it thinks it isn't there.

I have tried to select the Force Invites to be sent to IP of Registrar but that didn't seem to help. Any ideas how I can stop the update request from re-querying the DNS name and make it sticky with the IP A address?

 

[Saqqara]

What dns record is being updated,

 

[bigdessert]

We are using thinq so the DNS record that we use for registration is a.lcr.thinq.com

 

[AWS2P]

To avoid headaches use SIP supported providers

 

[bigdessert]

This is obvious and not what I came here for. My reasoning for the post is assistance or even direction to correct the problem with the existing provider. Thanks for you generous input though.

 

[Saqqara]

Can you not setup another dns which is used solely for 3CX i.e. 3CX dns and take it out of the load balancing so it only uses one link.

Switch over to the other link in the event of a failure.

 

[bigdessert]

I wish I could, but I cannot control the provider DNS A name. Surely I could create my own DNS A name and point it to a single one of the round robin IP addresses but then comes load issues and having to keep an updated list of IP's to change.

 

[Saqqara]

Are you using 3CX fqdn or your own for 3cx ?

 

[bigdessert]

This is for outbound calling so the 3CX FQDN or my own doesn't come into play. The FQDN I am talking about is the SIP registration FQDN set in the trunk.

 

[cobaltit]

You don't control the provider's DNS A record but if you can control the DNS server your 3CX instance uses (or just make a host entry locally) this may resolve the issue. But you said the upstream CLEC so I don't know that what you are trying to do is actually your responsibility if I'm interpreting it correctly. If you are registering to sip.unsupportedprovider.com and some calls work fine through one of their upstream providers and other calls fail with a specific provider then your unsupported provider should be resolving the issue, not you. I'm not even sure you can.

 

[AWS2P]

HI,

This is obvious and not what I came here for. My reasoning for the post is assistance or even direction to correct the problem with the existing provider. Thanks for you generous input though.

Obviously I know when a thread is open is for help needed ,my short answer was only like 3CX could answer you, this is not supported, no warranty it works properly , so sorry you are alone.
3CX community is fantastic help way, but sometimes it can be a lot of time consumming for no fix at the end.
Finally ,may be supported SIP provider is not so idiot solution
Hope you will fix it
Have a good day

 

[leejor]

If you are based in North America, and the issue, at this time, is only on Toll Free numbers, there may be a way around that. If you do a search, there are a number of ways to route Toll Free numbers without cost.

http://www.sipbroker.com/sipbroker/action/providerWhitePages
(scroll down to *800)

 

[YiannisH_3CX]

The registrar you mentioned only resolves to one A record which should not be a problem. Are you suggesting that this A record changes to a different IP while the call is in progress?
If that is the case then i can see how this can cause issues with the DNS resolution. Without testing this i believe that the changes in the DNS in update 3 might resolve the issue. Again this was not tested so i could be wrong.
For now you can just set a fixed IP in the registrar so you avoid the DNS resolution. Since the provider is using the IPs for load balancing all IPs should be active.