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New Member

Hook flash on an Cisco IP Phone

I have Cisco Unified CM 6.1 running and I need help in configuring an option to transfer a call to the PSTN and release the line - like similar to the flash option in an analog phone. In Cisco IPCC Enterprise this is called as "Take Back and Transfer" or "Transfer Connect".

The purpose is to release a call coming in on POTS line, so that the POTS line is not used up on an external call transfer.


Re: Hook flash on an Cisco IP Phone

I think you are going to need to talk to your provider on this. Basically, you need to send a message to the provider, thelling their swicth to diconnect this line and send the call to a different number. I don't know of a standard way of doing this.

New Member

Re: Hook flash on an Cisco IP Phone

This is an existing working system with Nortel. So the Telco is already setup for this function. The Nortel system is being replaced with Cisco UC Manager 6.1 and I am trying to emulate that functionality in the Cisco IP Phone so that they reroute the call back over the PSTN and release the line.

Basically, I will have to have a flash key emulation to send a signal to Telco for call transfer and then get a dialtone to dial the number where the call needs to be routed.

I remember seeing a flash key option on a Cisco IP Phone on a CME, but I am not sure how it works. I am looking for somthing similar UC Manager.

New Member

Re: Hook flash on an Cisco IP Phone

I am including some more additional information on what I am trying to achieve.

The original setup was the Nortel system. The setup included 5 POTS lines coming to the Nortel system as well as the PRI. The POTS lines are for high importance (Emergency) calls that come thru when an 800 number is dialed. Sometimes the calls are just for customer service and not the high importance calls and hence they need to be forwarded to the customer services department. But doing so with the usual transfer option will not release the call from the analog line. They do not want to use the analog lines for non-critical calls and hence when a call comes in over the POTS line, and it is not critical, the user on the Nortel phone presses a (link key in Nortel terms) hook-flash button and then presses a speed dial button (which has the transfer number). This initiates a call-transfer at the TELCO end, and the call is transferred from the POTS lines to the PRI and the customer service phone rings. The POTS line is freed up and available for the next call.

The Nortel documentation explains this as “Centrex Switchhook Flash (THF) permits the user to signal the Central Office during a established CO call, requesting activation of a CO based service, such as call transfer, 3-way calling, conference etc.. The THF is invoked when the telephone is on active 2-way trunk call and the THF is enabled in the trunk's Class of Service. This feature is not supported on BRI or PRI interfaces, but it is supported on CO, DID, FX, Analog.” I am not sure if this helps, but just wanted to give you an insight on what is accomplished at the Nortel system with the hookflash.

I am trying to emulate the call release from the FXO line and transfer the call to another number in the CUCM 6.1 setup. Any help in this regard is very deeply appreciated.


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