There are certain Asterisk features that can be activated while a call is in progress by quickly entering two specific characters from the touch-tone pad. These include ## (In-Call Asterisk Blind Transfer), *1 (In-Call Asterisk Toggle Call Recording), *2 (In-Call Asterisk Attended Transfer) and probably a couple others. Unfortunately, by default you must enter both characters within 500 ms (one-half second) and many people can't find and punch in both characters within that period of time. Here's how to increase the inter-character timeout:

Open the file /etc/asterisk/features_general_custom.conf in any text editor. The file should already exist in FreePBX, but it may currently be empty. If, for some reason, you need to create it, make sure the ownership and permissions are correct (matching those of the other features*.conf files).

Add this single line:

featuredigittimeout = 2000

Then save the changed file.

That increases the timeout to 2 seconds (2000 ms). If you want an even longer timeout, increase the value (in ms), although it's probably best to keep it as short as your users can tolerate so that normal actions like moving through an IVR during an outgoing call don't inadvertently trigger an Asterisk feature. Most people can hit *1 or *2 within 2 seconds, perhaps with a bit of forethought.