3CX Dialing Rule

[PeterCheng]

Hello sir,

I have an issue want to clarify:
I have a phone with ext. 1000, and there is ext. 1150 in 3CX PBX. And I have a sip trunk connecting to another PBX, which include ext. 1100-1200.
I'd like to know what will happen when I dial 1150 and 1160?
In my previous opinion, when dialing from 3CX, it will search its extension database first , if no, it will send out to another PBX via sip trunk
if I have a outbound call rule with Calls to numbers starting with prefix 1 and length is 4.
so regarding to my scenario, when dialing to 1150, the phone registering to 3CX will ring, even there is a 1160 in another PBX; when dialing to 1160, it will search DB first. Because there is no ext. 1160, it will then send the call to another PBX through sip trunk, and ring the ext. 1160 in that PBX.
The concept for 3CX is correct? Thanks.

Peter

 

[JohnS_3CX]

Hi @PeterCheng

The PBX checks the dialled number against its own extensions, and if no matches are found it will then look at your outbound rules.

But if you have a trunk going to another PBX, it's best you should have a prefix for that trunk (for example 9) and dial out 91150 then strip the 9 before sending the call to the other side. This way there will never be any chances of conflict.

 

[PeterCheng]

Hi @PeterCheng

The PBX checks the dialled number against its own extensions, and if no matches are found it will then look at your outbound rules.

But if you have a trunk going to another PBX, it's best you should have a prefix for that trunk (for example 9) and dial out 91150 then strip the 9 before sending the call to the other side. This way there will never be any chances of conflict.

Hi JohnS_3CX
Thanks for your feedback.
So for my scenario, in normal situation it works. But if the extension exists in both PBXs, caller could be confused.
Because right now all the extension no. are registered in our NEC PBX, and we are planning to migrate all the extensions to 3CX PBX. We are having POC test so we create a few extension in the 3CX PBX, and I hope that if I'm a user in 3CX PBX, I can use the same extension no. and I can not only dial the users who have migrated to 3CX PBX, but also dial the users who are in the NEC PBX. Both PBXs are connected via SIP trunk. I hope all the users don't need to change their dialing behavior, no matter in 3CX PBX or NEC PBX. They still own the same extension no. What could be the best way for my requirement? If 3CX's dialing rule is to search itself first, and then search outbound call rule, once users have been migrated to 3CX from NEC, he/she can call in the same way.
Thanks.

Peter

 

[JohnS_3CX]

Hi Peter,

If you migrate 1 extension at a time, and make sure the same extension number does not exist in both PBXs at the same time, then you should not have any major issues (and you will not need dialling a prefix).

 

[PeterCheng]

Hi Peter,

If you migrate 1 extension at a time, and make sure the same extension number does not exist in both PBXs at the same time, then you should not have any major issues (and you will not need dialling a prefix).

Hi John,

Thanks for your comment.
So may I know what could be the technical problem if the extension exists at both PBXs?
Thanks.

Peter

 

[JohnS_3CX]

You could have conflicts: If an extension (let's say 1200) is migrated to 3CX but you did not delete it in NEC, then a NEC user who dials 1200 will not reach 3CX. They will reach the 1200 that exists in NEC, and they will probably get voicemail or busy tone.

 

[leejor]

It is also going to depend on the dialplan flexibility in the NEC and how it is setup to determine when to sent calls to 3CX. It may still assume that an extension number is still local even if it does not exist. many PBXs do require a prefix, to sent call out over a trunk. So while 3CX will look internally first, for a SIP ID or extension number, before moving on to an outside rule, the NEC may not be able to do that.

 

[jcostlow]

On NEC systems you have to designate what extension numbering you would want an F-Route for. I.E. on an older system we are going to move to 3CX exts 100-500 are usable but the extensions in the 800 range have a route to the SIP tie line on the fax server.

That is for SV series. SL should be similar but I haven't worked with them.