Ask Mr. Andrews: What Are My Options for Paging with trixbox?

July 17, 2008 by Garrett Smith

Dear Mr. Andrews:

I run a manufacturing facility and we recently implemented trixbox to replace our legacy phone system. We have a four-zone analog paging system that was integrated with our previous phone system. What are my options for paging with trixbox?

Ask Mr. Andrews

“Desktop” paging, whereby you dial a number and all the phones in the dialed call group pick up automatically, go into hands free, and play through their speaker what the caller is saying, is supported on trixbox using a number of IP phones. Snom phones, Grandstream GXP Series Phones, Aastra 480i and 9133i, and Polycom phones all support desktop paging.

A note about setting up desktop paging with Polycom phones:

You MUST provision the phone from a FTP server to
load the Polycom config files, then edit sip.cfg, search for
“alertInfo” and set “voIpProt.SIP.alertInfo.1.value” to equal “Ring
Answer.” Now reboot your phone to load the new config option.

For overhead paging, you can make an Asterisk Extension go to the sound card, and wire its output to a traditional external paging system. You can also get boxes to interface a phone FXO or FXS port directly to a sound system. Examples:

  • Valcom V-2001A
    • connects to an FXO port, so more suitable for interface with PBX or other phone system
  • Viking CPA-7B Paging/Loud Ringing Amplifier
    • Has both FXS and FXO ports.
    • Can connect to a normal ATA FXS port in place of a phone
    • Example: Ethernet – SIP ATA – Viking CPA-7B – paging speakers
    • Other models available with multi-zone paging, etc.
  • Radio Design Labs ST-TC1 Telephone System Coupler
    • Also sold as: Smarthome Product
    • connects to an FXO port, so more suitable for interface with PBX or other phone system

A third option for paging is to use an overhead, SIP-enabled speaker manufacturer by Cyberdata. Cyberdata offers a recess mounted, SIP enabled speaker that is PoE powered, and can be setup like a normal extension off your Trixbox system. In this scenario, you could place four speakers in your current paging zones, and assign each zone an extension. You could also group these extensions into a “page all” call group. Cyberdata also makes an amplified version of their speaker system for noisier industrial environments.


  • With very little work I have also gotten Linksys and Cisco phones to work well with the Asterisk paging system. I set ours up to allow a page (one-way announcement) or handsfree intercom to one or many phones. To help the user of the phone know which type of communication is coming I prefaced the live speaker/mic with a sound and pick a different sound for the page/intercom. When the calling party hangs up I also insert a little closing sound file so everyone knows the speaker/mic is off. You have to do a little checking to make sure the phone is not in use before attempting either function and if you are doing a page or intercom and no devices are available I return a busy signal so the orginator knows the called extension/group is busy. Being a StarTrek fan I used some of the same sounds they used on the tv show for intercom on, shipwide page and conversation complete signal. People always get a kick out of the sounds when they hear them.

  • Dannvan Morrison

    I hav e linksys wip310 It will not register witj trixbox pro ee. Can you help?

  • Soundguy

    Douglas–can you please let us know how you did this with Linksys and Cisco phones? How did you configure them? This is something a lot of people want to know.

  • George Villagran

    I’m goinig through a similar situation, in my case I have been trying to make a group paging work. I have set up a paging group to several extensions, we are using a gateway and a DFT box before the amplifier and for some reason when I dial the page group the bell sounds in all areas but the voice is not coming out of the speakers. Any ideas?

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