Solved 3CX outbound call issue

[101151205509]

I am facing the issue with outbound calls, when i dial the mobile number getting error like" Call forbidden by administrator". During this time i have to refresh the registration of SIP TRUNK manually in SIP Trunk settings, after refreshing the SIP Trunks, i can able to make outbound calls. Kindly share me what is the issue with configuration.

Since 10 days i am facing this issue and inbound calls are working fine.

 

[eddv123]

Run a PCAP trace on 3CX:
https://www.3cx.com/docs/capture-network-traffic/

Replicate the issue.

Go to Telephony >> VoIP Calls >> Call flow.

See whether the error is being returned from the provider (if a provider leg exists - should be 2 legs if they do). It could be a configuration issue on their side, or setting that needs to be altered.

If no provider side leg exists look at your own PBX.

 

[YiannisH_3CX]

When the issue occurs does the trunk appear as registered under the sip trunks tab? If so check your activity log .It should point you to the right direction.

 

[leejor]

You didn't mention if this happens with calls to non-mobile numbers. In many countries, calls to mobiles can be charged at a much higher rate, than calls to landlines, and may be blocked by default. As mentioned, the Activity Log will tell you if you need to contact your provider.

 

[101151205509]

You didn't mention if this happens with calls to non-mobile numbers. In many countries, calls to mobiles can be charged at a much higher rate, than calls to landlines, and may be blocked by default. As mentioned, the Activity Log will tell you if you need to contact your provider.

Sorry, i missed to mention. Its happening for all mobile numbers and non-mobile numbers as well.

 

[101151205509]

When the issue occurs does the trunk appear as registered under the sip trunks tab? If so check your activity log .It should point you to the right direction.

Yanish, here i am sharing the wire shark log as screenshot, it may be helpful.

 

[101151205509]

Run a PCAP trace on 3CX:
https://www.3cx.com/docs/capture-network-traffic/

Replicate the issue.

Go to Telephony >> VoIP Calls >> Call flow.

See whether the error is being returned from the provider (if a provider leg exists - should be 2 legs if they do). It could be a configuration issue on their side, or setting that needs to be altered.

If no provider side leg exists look at your own PBX.

Attached the log. kindly check.

 

[eddv123]

10.0.78.10 is a range of IP's owned by Netia SA (polish SIP trunking provider) so this response is coming back from them (403 forbidden) which is a client side request error.

Without seeing the INVITE message being sent I cannot say if there is something in this that the provider does not like however it could be:

• presentation of the number (some providers want it in geo format).
• IP being sent in the 'Contact' (SIP) and 'Connection'(SDP) fields (or possibly another header).
• If all calls less likely - but geo permissions are common settings which are blocked by default.

 

[leejor]

Since 10 days i am facing this issue and inbound calls are working fine.

Was this working previously? If so...what (settings/firmware/hardware) changed 10 days ago?

You will have to ask the provider why they are forbidding the calls.

 

[101151205509]

Now mentioned issue resolved. checked the logs and changed as transport=udp in sip settings.
Previously it was transport=tcp.

Also changed the caller ID details as well.

Thanks for your quick help.

 

[eddv123]

TCP traffic is more friendly for firewalls than UDP (due to its 3 way handshake).

One explanation is that the provider only accepts traffic in TCP format but this is rare, who are you using as a trunking provider?

 

[101151205509]

we are using TATA SIP (India). Checked with provider end accepts UDP traffic.

 

[eddv123]

Yes i set this trunk up myself just before the holidays and didn't have to do this.

Not that it will help now but i documented it as well.
I will post up the document as a forum post as you are about the third person to be setting up TATA on the forums I have helped.

 

[101151205509]

Thanks for sharing this docs, it will be useful for me in future.

Even though i didn't configured the SIP trunks before, but still i get ideas about the SIP configuration with 3CX after reading your document. Thank you so much.

 

[eddv123]

No problems, have removed and posted it as a separate forum string now however:
https://www.3cx.com/community/threads/tata-communications-trunk-3cx-integration.70050/

 

[YiannisH_3CX]

Glad to see your issue has been resolved and thank you for the update