I have 2 cisco spa941 phones, is there a way to configure them so that when an extension is use and the line will show in use on the other phone? I'm new to programing these phones but know a little.
I have this working on a SPA942. On the "Phone" tab of the web interface of the IP phone you can add the following under the "Line Key 2" (3 or 4)] section. Where x.x.x.x is the IP of your 3CX and extension is the extension number of the extension you want to monitor. Also change the "Extension:" to "Disabled" and the "Share Call Appearance:" to "Shared". When the other phone is busy the LED light turns red.
BLF provisioning doesn't seem to work on my SPA942's and I have to add them manually through the ip phone web interface. I presume the SPA941 might be in the same boat.