User’s Guide
8
Hook-flashes
Hook-flashes are one of the more complicated operations needed in the NexPath TelephonyServer. The rea-
son we need them, though, is that ifyou press the keys on your telephone keypad while in the middle of a
normal call, the NexPath TelephonyServer simply passes these key presses on to the other party. This is
handy when the other party’sphone system can do something with them, such as route your call to an exten-
sion within their building, but itmakes it difficult to signal the NexPath Telephony Server that you want to
do something special like put a call on hold once you are in the middle ofa call.
Some telephone systems solve this problem by requiring that you use special keys on their proprietary
phones (sometimes misleadingly called digital phones). The problems with special phonesare that they are
expensive, they only work on onesystem, they become obsolete quickly, and they often do nothave other-
wise commonly available features such as speed-dial.
On the NexPath TelephonyServer, you can signal the system that you want to do something special like put
a call on hold while in the middle of a call by performing a hook-flash, then entering the command sequence
for the operation desired.Hook-flashes are done by quickly depressing and releasing the hook switch1on
your phone, or by pressingthe flash key on your phone.
Note, though, that perfecting the art of performing hook-flashes using the hook-switch might take a little
practice. Youmust depress the switch for long enough to make it obvious to the system that you want to sig-
nal it but not so long that the system thinks you hungup. A valid hook-flash is accomplished by depressing
the telephone hook switch for an interval of greater than 50 milliseconds and less than 1000 milliseconds (a
millisecond is 1/1000ths of a second, so 1000 milliseconds is one second).
Some phones come witha button which performsthe hook-flash function. Nortel telephones label it
the Link key. Care must be used with some telephones that have this button,however, since they can issue a
hook-flash for a full 3/4 ofa second, which is a fairly long time. Some telephonedo not properly collect the
keys you enter during this flash interval. If you begin entering other keys of a sequence before the pre-pro-
grammed flash time has ended, many older phones will block the subsequenttones, and the NexPath Tele-
phony Server will not “hear” these other keys and you will likely get an error message.
Testthe telephones you are using, and, if the telephone does not queue the keys, make sure you have waited
until the preprogrammed flash time is over before pressing other keys. Or, better yet, if you have one of
1. The hook-switch is the switch that gets depressedby the handset when you hang up your phone.
Flash
user.bk Page 8 Wednesday, March 7, 2001 10:34 AM