503 Service Unavailable - only on one external called number

[Dan Furse]

Hi,

We are getting an odd error when calling one specific external number. The call rings once then fails with Server Internal Error displayed on the handset.

I've replaced the external number with nnnnnnnnnnn because it's a valid working number - I can call it fine from my mobile!

Activity log shows the following:

05/24/2018 5:05:34 PM - Call to T:Line:10000>>nnnnnnnnnnn@[Dev:sip:[email protected]:5060] from L:1954.1[Extn:289] failed, cause: Cause: 503 Service Unavailable/INVITE from xx.xx.xx.xx:5060

05/24/2018 5:05:34 PM - Exception: ParseException E:\jenkins\workspace\15.5SP4\SPBuild\Sources\3rdParty\Resiprocate\rutil/ParseBuffer.hxx:230, Parse failed unexpected eof in context:
nnnnnnnnnnn
^
@ E:\jenkins\workspace\15.5SP4\SPBuild\Sources\3rdParty\Resiprocate\rutil/ParseBuffer.hxx:230


System is 15.5, ISDN trunk via a Patton Smartnode. All other calls work fine.

Any ideas?

Thanks,
Dan

 

[leejor]

If you can reach it from another device (your mobile), and other outgoing calls work fine, then it is probably one of two things ...
either the call is being rejected, at the destination, because of the Caller ID you are sending, or, your provider is having an issue in passing the call on (perhaps the carrier that they use).

I would see if your provider can offer any assistance.

 

[YiannisH_3CX]

I will have to agree with @leejor on this one. Your provider should be able to help you determine why this specific number cannot be reached by the PBX.