[miro]

Hello,

we have 3cx phone sytem attached to 2N VoiceBlue Lite GSM gateway we created SIP trunk between them, when we call some mobile number from internal extension (example 200) registered on 3cx phone system and our call goes via GSM gateway we need to retain extension as a record on GSM gateway so when an outside number calls back can reach extension 200.


How to set outbound parametars on 3cx for SIP trunk which is made between 3cx phone system and GSM gateway, so calls can reach GSM gateway and retain local extensions ?


Thanks

[danhriscanu]

Hi,

One way to do this from 3CX side is to configure different DIDs for every extension that you want to be reachable from outside and route to them accordingly in Inbound rules. You also will have to match those DIDs with your extension outbound Caller ID, so when an extension will call an external number that person will see the specific DID of that extension and he will be able to call it back.

I don't know if there are such settings on your GSM Gateway but maybe somebody else can help you with this.

[miro]

i created DID for every extension.... problem is when i am calling some external mobile phone (e.g. from extension 300) in sip message there is 300@ip.address when my call is going to the 3cx, 3cx have outbound rule for mobile network to route them to GSM gateway, when that call is coming to the GSM , GSM see in the sip message from 1001@ipaddress (virtual line), or 100@ip.address (number of trunk) and that call is forward outside to the mobile network. if that call was not connected there is an option in gsm gateway to keep that call in routing table so when pearson who has missed call, call back gsm gateway can automatically forward that call to extension form which call was originated. problem is when i look that routing table og gsm gateway instead of real extension number which originated that call there is a "100" or 1001. what i need to setup is when some call from extension 300 and that call is passing through sip trunk between 3cx and gsm gateway ,to came to the gsm gateway as 300@ip.addd, and when person from mobile phone call back gsm see in his table when someone call that mobile number on gsm gateway can automaticly forward that call to extension xy. right now everything is going to extension 100 (secretary).

there are some options in outbound parameters on trunk, from user part , from host part, from display name.... i think that i can solve my problem with that.. I dont know exactly what to change...

P.S. my extension have otubound caller ID setup for another sip trunk which is on the same 3cx and I cant change it.

[miro]

i also founf this post:
dids-and-outbound-caller-id-4772.html

it seems that there is no way to send original extension number to gsm gateway without configuring outbound caller id on each extension (and I cant change that because of the second trunk)???

please help,
thanks

[danhriscanu]

Hi,

Indeed in the Outbound parameters of a VoIP trunk you can modify SIP fields like From: User Part and put whatever you want but pay great attention at those parameters because you can mess up everything. You need a very deep through understanding of SIP to play with those. Modify them on your own risk, but I suggest a testing environment to do this. On the other hand, if you modify lets say "From: User Part" to display an extension instead of trunk ID (ex: "sip:11000@10.172.0.89:5060" replaced with "sip:300@10.172.0.89:5060") in Invite message, you will do this for all the calls that pass through that trunk. You cannot put there a variable to be fulfilled automatically by your extension number.

Good luck,

[miro]

that is all right, i need to keep original extension number for all calls which are passing through that sip trunk. which option do I must to set in "from user part" to get that number of extension is not overwrited?

[danhriscanu]

That is what I was trying to say to you. You cannot keep original extension number of the calls. To better understand those SIP fields you should read the SIP RFC 3261. http://www.ietf.org/rfc/rfc3261.txt