Spoofing NOTIFY Message

[pksml]

Hello fellow FusionPBX-ers. I am near to pulling my hair out on this one...

I have Yealink T46S phones. It's a commonly-reported problem that when you go in to DND mode, the line key LED will not switch to red on everyone else's phones for your extension.

So I thought I could spoof the NOTIFY message that occurs when a call comes in.

For instance, here is a NOTIFY message that tells one of the phones that a call has been answered on extension 120. If I could spoof a message like this, I could tell the other extensions that extension 120 is in DND with the LED turning red.

NOTIFY sip:120@192.168.2.102:12569;transport=TCP SIP/2.0
Via: SIP/2.0/TCP 192.168.2.2;branch=z9hG4bKU0aS9K06a1BtS
Max-Forwards: 70
From: <sip:110@myvoipserver.com:5060>;tag=eOGt63qVuTTR
To: "120 - Cat" <sip:120@myvoipserver.com:5060>;tag=1943431340
Call-ID: 0_1943505683@192.168.2.102
CSeq: 1532010201 NOTIFY
Contact: <sip:110@192.168.2.2:5060;transport=tcp>
User-Agent: FreeSWITCH
Allow: INVITE, ACK, BYE, CANCEL, OPTIONS, MESSAGE, INFO, UPDATE, REGISTER, REFER, NOTIFY, PUBLISH, SUBSCRIBE
Supported: path, replaces
Event: dialog
Allow-Events: talk, hold, conference, presence, as-feature-event, dialog, line-seize, call-info, sla, include-session-description, presence.winfo, message-summary, refer
Subscription-State: active;expires=1317
Content-Type: application/dialog-info+xml
Content-Length: 586

<?xml version="1.0"?>
<dialog-info xmlns="urn:ietf:params:xml:ns:dialog-info" version="83" state="full" entity="sip:110@myvoipserver.com">
<dialog id="a1aa3942-d078-42af-91be-d52a0fbe6bbf" direction="recipient">
<state>confirmed</state>
<local>
<identity display="110">sip:110@myvoipserver.com</identity>
<target uri="sip:110@myvoipserver.com">
<param pname="+sip.rendering" pvalue="yes"/>
</target>
</local>
<remote>
<identity display="SARA ROGERS">sip:4134044133@myvoipserver.com</identity>
<target uri="sip:**110@myvoipserver.com"/>
</remote>
</dialog>
</dialog-info>

Would I need to use the ESL to do this? Any other ideas to solve this dilemma? Thanks in advance and Merry Christmas and Happy New Year to you!

 

[Adrian Fretwell]

Yes, you can do it. It isn't really spoofing a NOTIFY, you are just asking FreeSWITCH to send out a NOTIFY message. Generally you would use ESL for this but it can also be done via mod_amqp using the TAP.Command exchange.

If you go down this route, please be aware that the phone will automatically revert the line key back to green after a period of time, so you will probably need to run a background process to keep refreshing it to be red. There may be a better or more conventional way of doing what you want, but it is not something I have ever investigated.

FusionPBX does this for busy lamps that are used for call flows such as night service. it is a .lua script that is run at startup, you can find the script here:
https://github.com/fusionpbx/fusion...witch/resources/scripts/call_flow_monitor.lua

DjangoPBX has two options, a background process that runs continuously or a script that can be fired ad-hoc or from a regular cron job. Links to both below:
https://codeberg.org/DjangoPBX/DjangoPBX/src/branch/main/pbx/scripts/call_flow_monitor_daemon.py
https://codeberg.org/DjangoPBX/DjangoPBX/src/branch/main/pbx/scripts/call_flow_monitor.py

The latter will be the easiest to understand at a quick glance.

You should be able to adapt any of the above to meet you needs.