Can only dial branch office using extension, main number does nothing

[frnkgrffth]

We have a pbx with Cisco SIP phones running on AWS, at least that's what I've been told. There are three branch offices with about 20 employees in each. The users in each branch can successfully make outside calls and call other employees in the other branches by using the extension numbers "5003", "5004", etc... but in certain cases they need to dial the other branch by using the main PSTN number of the other branch. The users are telling me these calls drop off into hyperspace. No sound, no noise, no call.

I'm just getting into this issue and it's been a long time since I've had to resolve PBX issues. The AWS pbx system is Elastix or something and it's running Asterisk which I have worked with before but again it's been a long time since I delved into IT issues.

Sounds like a network routing issue but I'm just starting to hack through this one. Will post more as I research it.

[balaji.bandi]

but in certain cases they need to dial the other branch by using the main PSTN number of the other branch. The users are telling me these calls drop off into hyperspace. No sound, no noise, no call.

This you need to troubleshoot on asterisk how the call routing ?

this looks for me more of transcoding issue ? what transcoding you using ?

what happend when you call PSTN - is the call land on asterisk ?

[frnkgrffth]

Thank you for the prompt reply. There are still unknowns in this issue and the knowers are not available just yet. When the users dial any outside lines there is no trouble. And if they dial the other employees by using the extension numbers all is well. But when they dial the outside (PSTN) number of the other branches, the calls just go unresponsive. No sound, not busy signal, just silence. I should be able to meet with the senior members of their IT staff later today or Monday. Will post back when I can.

[Leo Laohoo]

---

@frnkgrffth wrote:
Sounds like a network routing issue but I'm just starting to hack through this one. 

---

No, it is not. 

---

@frnkgrffth wrote:
The users in each branch can successfully make outside calls and call other employees in the other branches by using the extension numbers "5003", "5004", etc... but in certain cases they need to dial the other branch by using the main PSTN number of the other branch. The users are telling me these calls drop off into hyperspace. No sound, no noise, no call.

---

If these are Cisco phones, the dial plan is wrong.