Outbound call - 503 Service Unavailable for specific phone number

[eagle37]

Hello,

We are getting a 503 Service Unavailable error after a 30 second timeout from our SIP provider when dialing a single number.
This error is only found in the 3cx logs. The caller sees 500 internal server error on our yealink phones.

All other calls are completing correctly.

When dialing this same number form the PSTN, I get a disconnected message that repeats the number back to me.
When I contact our SIP Provider and they test the call, they say the call ends immediately with no message and no error.

Is there some exit routing a need to setup to provide an error message for calls that fail?

Thank you

 

[AWS2P]

Don't understand what you need more? or expect more ?
you found a 503 which means remote end is not available, so your pbx is working properly and you said each check you've done alone or with provider gave you same result.

 

[eagle37]

The caller sees 500 internal server error on their phone so they keep retrying because they don't know what the problem is. How do we present an error to the caller so they understand the number is disconnected?

 

[YiannisH_3CX]

Your provider (or the provider the number belongs to) knows this detail and should play a message telling you the number is disconnected. The PBX can only report the error it receives from the provider after the call times out. 503 service unavailable can mean a number of things not only that the number called is disconnected.

 

[AWS2P]

Perhaps they are on maintenance and their number is not working in normal conditions , and perhaps another day it will work fine and answer properly

 

[leejor]

Unfortunately, when calling a number that does not complete "normally", the number is not in service, or routes to a destination the cannot be completed, originating from different networks will give different results.
The destination, that is providing the recording also sends back a message over SS7, or an ISDN trunk, letting the calling party know that the call is not to be billed, and what condition give the caller The originating provider can then choose to end the call at that point, or leave the audio path until the party that dialled the call has heard a recording (if provided). It could also be a fast busy tone (no circuit available) Because doing that is tying up a channel, many will choose to simply drop the call, and send back a message to the originator, and expect them to "deal" with what the caller hears. There may very well be a different message sent, indicating a number is not in service, from a your call cannot go through message, but at some point, a provider may lump a number of message types into one and send a 503.

Your VoIP provider may have connections to the PSTN network through another party, so it may not be their choice as to what message is sent to you, they may just be passing on what they receive.

At this point, 3CX does not have a method of linking a specific SIP message to a wave file, to give an audible response to the caller.