Sunday, June 5, 2011

Telex Radio Dispatch System Integration with Cisco Unified Communications. Part 3

A reader has asked about our progress with this and it reminded me I haven't talked about our results.

I want to just reiterate what the Telex Radio Dispatch System is.

Telex provides an integration with multiple communications systems. This is commonly used in an environment where dispatchers communicate on multiple communications systems. The Telex C-Soft console provides dispatchers a point and click interface to interact with the various communications systems. Dispatchers can increase or decrease audio volumes from a specific radio system. They can also click on a specific radio system and, through their headset, talk on a particular radio system. The Telex Radio Dispatch System also allows for a phone system integration.

For example, consider an ambulance company. Their ambulances provide services for town A, town B, town C. All these towns communicate on specific radio channels. The ambulance company has radio towers and systems that connect to each radio channel/network. For each radio channel/network/town, Telex has a VoIP adapter that converts the radio communications to VoIP. The Telex system multicasts the audio from the radio system to the dispatchers.

For Cisco centric people, think Cisco IPICS.

We were brought in to integrate a Cisco CallManager phone system with the Telex system.

The primary problem we had was the integration between the physical phone and the Telex C-Soft Dispatch console. The physical integration is provided via in-line adapter connected to the phone (See Part 1). Often a NENA compliant phone is used. Cisco, as well as most other vendors, do not have NENA compliant phones (We later learned NENA compliant phones can cost several thousand dollars a piece). When an inbound call is presented to the dispatcher, they can answer the call by clicking on the appropriate icon on the dispatch console.

We connected a Cisco IP Phone to the Telex in-line adapter. On an inbound call, the dispatcher had to physically press the appropriate button on the phone to answer the call. This would not work, the customer wanted to use the C-Soft Dispatch Console to click and answer the call.

We tried removing a physical phone all together and use the C-Soft SIP phone. This worked ok for receiving calls. The C-Soft SIP phone was configured as a basic SIP phone in CallManager. To place outbound calls, dispatchers had to append @10.1.1.1 (CallManager's IP Address) to every outbound call, either internal or external. I held out hope the SIP client would work, but it looked to me like a freeware no frills SIP softphone. For the customer, this was a no go.

We found a small company in California which produces a box which connects to a physical phone (pretty much any phone) and provides the proper signalling to integrate with Telex (Sorry I don't have the companies name right now, but I can find it on request). With this box, dispatchers could click to answer the call, however C-Soft didn't pickup the audio.

After much troubleshooting we found the phone system needed to generate a tone or a beep when the call was answered to cause C-Soft to "hear" the call and mix the audio. After banging our heads together a co-worker suggested enabling the "call recording tone" on the dispatchers phones. This is normally used to play a tone to callers indicating the call is being recorded. We were not using a call recording system, but playing this tone caused the C-Soft console to recognize the call and mix the audio.

Telex Radio Dispatch System Integration with Cisco Unified Communications. Part 1

Telex Radio Dispatch System Integration with Cisco Unified Communications. Part 2

Home