503 Transport Failures

[Ricky Horne]

I get the below issue appearing for around 90 seconds every other day, usually in the afternoon.
It only affects dialling out. Incoming calls are still fine.

SIP Server/Call Manager ID: 12294
Call or Registration to mobile_number@(Ln.10001@*SIPTrunk*) has failed. 0.0.0.0 replied: 503 Transport failure: no transports left to try; warning: No other DNS entries to try (7,110); internal

OS: Debian
3CX Version: 16.0.3.676 (on premise)

The SIP Trunks all re-register at this time so i believe this fixes the issue however it is becoming rather annoying and i am not sure of a resolution.

 

[Alphabetic]

See if this thread applies

https://www.3cx.com/community/threa...round-15-18-second-to-ring.70447/#post-311103

 

[ECOM GROUP (Mauritius)]

I get the below issue appearing for around 90 seconds every other day, usually in the afternoon.
It only affects dialling out. Incoming calls are still fine.

SIP Server/Call Manager ID: 12294
Call or Registration to mobile_number@(Ln.10001@*SIPTrunk*) has failed. 0.0.0.0 replied: 503 Transport failure: no transports left to try; warning: No other DNS entries to try (7,110); internal

OS: Debian
3CX Version: 16.0.3.676 (on premise)

The SIP Trunks all re-register at this time so i believe this fixes the issue however it is becoming rather annoying and i am not sure of a resolution.

I am having the same issue , First time i dial it take around 15-20 to ring or does not ring at all. second time i dial it ring normal or on the third time.

Using on Premise debian too.
i am not yet find a solution.

I would advise you update your 3cx to the latest version so that people here can help better.
Latest Version Debian: 3CX Version: 16.0.4.493

 

[cobaltit]

As @ECOM GROUP (Mauritius) suggests definitely upgrade to Update 4. There were some updates related to DNS if you are using auto discovery on the trunk. You might also try forcing UDP (or whatever your provider recommends) as another option. Lastly, since two of you are having this issue, what are you using for DNS?

 

[ECOM GROUP (Mauritius)]

As @ECOM GROUP (Mauritius) suggests definitely upgrade to Update 4. There were some updates related to DNS if you are using auto discovery on the trunk. You might also try forcing UDP (or whatever your provider recommends) as another option. Lastly, since two of you are having this issue, what are you using for DNS?

@cobaltit I am using 8.8.8.8 4.4.4.4 on my debian machine as dns. trunk seem sleep after few minutes.. i have to trigger a call which take longer to ring or may not ring.. after second dial or third .. then it work. then after few minutes.. something seem to go on idle..

 

[cobaltit]

@ECOM GROUP (Mauritius)

Let's tackle your issue in your thread so as not to confuse this one.

 

[Ricky Horne]

Hi,

I use out internal DNS servers.

Our 3CX system continually fails to update to the next version which is where this issue may stem from.

I am about to add a 2nd outgoing route with a different provider to make sure the issue isn't with them.

I will add we were also having difficulty with our backup agent so until i rule this out and get 3CX updated there isnt much else I can try yet.

 

[JohnS_3CX]

Hi Ricky,

You should be able to run backups and perform upgrades. If these fail, they probably point towards another underlying issue, so I would agree that you should rules this possibility out before going forward.

If you have a good backup, you can reinstall from scratch and restore the backup during the installation phase, moving you up to update 4 at the same time. You can start a new thread on this if you are having trouble with it but don't forget to include all the relevant information as per here
https://www.3cx.com/community/threads/information-to-provide-when-requesting-help.67558/

And also include the hardware specs because an under-spec machine may cause services to stop