Change Public IP: Tracing an IP Address Ghost Through SIP Stack Analysis

[mgrollman]

We are using 3CX 15.5, and we are trying change ISP's and with it public facing IP address. We have swapped the old one for a new phone in all places we can find in the Management GUI, and cross checked where they are at with GUI Parameters, but we still have our 3CX using the old address in the Contact Field, which is making it hard to handshake correctly for media. Example below in Orange. Can anyone tell me where the Contact field here in this packet is derided from in the 3CX software config? Key item in orange. Much thanks!

Session Initiation Protocol (200)

Status-Line: SIP/2.0 200 OK

Message Header

Via: SIP/2.0/UDP 8.38.43.50:5060;branch=z9hG4bK1XXXXXX04389445rdb30570

Record-Route: <href="sip:[email protected]:5060;lr;transport=udp">sip:[email protected]:5060;lr;transport=udp>

Require: timer

Contact: <href="sip:14802XXX@65.113.137.XX:5060">sip:14802896065@65.113.137.XX:5060>

To: <sip:14802896065@184.183.25.XX>;tag=9b68ba51

From: "SCHULTZ STEVEN" <href="sip:[email protected]">sip:[email protected]>;tag=sanXXXX445rdb30570

Call-ID: href="mailto:[email protected]">[email protected].43.43

CSeq: 1 INVITE

Session-Expires: 36000;refresher=uac

Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REGISTER, SUBSCRIBE, NOTIFY, REFER, INFO, MESSAGE, UPDATE

Content-Type: application/sdp

Supported: replaces, timer

User-Agent: 3CXPhoneSystem 15.5.15502.6 (15502)

Content-Length: 273

 

[nub]

Reboot, and restart the phones to.

 

[cobaltit]

Check the Options tab of the SIP trunk:

 

[YiannisH_3CX]

Hello @mgrollman

Please note that you do not need and should not perform any manual changes to the PBX to update the public IP. You only need to navigate to Settings / Network and switch the option to Dynamic. Restart all services and let the PBX detect its new public IP. Once that happens you can switch it back to static.