Hi Phillip,
Hows things? Hope all is well with you :) If you are using SCCP (I'm guessing here);
Transfer and Conference are two features that use Hookflash. You will probably need to tweak these settings;
Hookflash Duration
Analog phones use hookflash to access a second dial tone to initiate some of the SCCP phone features listed in Table 2, such as transfer and conference. Hookflash is an on-hook condition of short duration that is usually generated when a phone user presses the Flash button on a phone. The duration of an on-hook condition generated by a Flash button varies for different phone makes and models. Cisco voice gateways measure the duration of detected on-hook conditions to determine whether they should be interpreted as hookflash or not. The duration of a detected on-hook condition is interpreted by Cisco IOS software as follows:
An on-hook condition that lasts for a time period that falls inside the hookflash duration range is considered a hookflash.
An on-hook condition that lasts for a shorter period than the lower limit of the range is ignored.
An on-hook condition that lasts for a longer period than the higher limit of the range is considered a disconnect.
The hookflash duration range for FXS ports is defined as follows:
The lower limit of the range is set in software at 150 ms, although there is also a hardware-imposed lower limit that is typically about 20 ms, depending on platform type. An on-hook condition that lasts for a shorter time than this hardware-imposed lower limit is not reported to the Cisco IOS software.
The upper limit of the range is set in software at 1000 ms by default, although this value can be changed using the timing hookflash-input command in voice-port configuration mode on the voice gateway. The upper limit can be set to any value from 50 to 1550 ms.
The following examples demonstrate the use of the timing hookflash-input command to modify the upper limit of the hookflash duration range for FXS ports:
If the timing hookflash-input command is set to X, a value greater than 150, then any on-hook duration between 150 and X is interpreted as a hookflash. For example, if X is 1550, the hookflash duration range is 150 to 1550 ms. An on-hook signal that lasts for 1250 ms is interpreted as a hookflash, but an on-hook signal of 55 ms is ignored.
If the timing hookflash-input command is set to X, a value less than 150, then any on-hook duration between Y, the hardware lower limit, and X is interpreted as a hookflash. For example, if X is 65, the hookflash duration range is Y to 65 ms (assume Y is 20 ms). An on-hook signal that lasts for 1250 ms is interpreted as a disconnect, but an on-hook signal of 55 ms is interpreted as a hookflash. An on-hook signal of less than Y is ignored.
From this good doc;
http://www.cisco.com/en/US/products/ps6441/products_feature_guide09186a0080483a76.html#wp1128916
Also, see this thread with a Great answer from Leo;
http://forum.cisco.com/eforum/servlet/NetProf?page=netprof&forum=Unified%20Communications%20and%20Video&topic=General&CommCmd=MB%3Fcmd%3Dpass_through%26location%3Doutline%40%5E1%40%40.1ddc9782/4#selected_message
Hope this helps!
Rob
