Page 313 - Asterisk™: The Future of Telephony

function. The call is then placed via the SIP channel using the service_provider we
created in the sip.conf file:

[outgoing]
exten => call,1,NoOp()
exten => call,n,Set(CALLERID(name)=${${WHO}_CID_NAME})
exten => call,n,Set(CALLERID(number)=${${WHO}_CID_NUMBER})
exten => call,n,Dial(SIP/service_provider/${E})
exten => call,n,Playback(silence/2&pls-try-call-later)
exten => call,n,Hangup()
Our service_provider might look something like this in sip.conf:
[service_provider]
type=friend
host=switch1.service_provider.net
username=my_username
fromuser=my_username
secret=welcome
context=incoming
canreinvite=no
disallow=all
allow=ulaw
And that’s it! The complete dialplan utilized for the hot-desk feature is displayed in full
in Appendix G.
How many things have you just thought of that you could apply func_odbc to? See why
we’re so excited about this feature as well?!

The func_odbc Backport
With Asterisk 1.4, you can use a backported version of func_odbc that uses a slightly
different configuration format. This allows you to use multiple DSN connections to
separate databases, and also to utilize the ${ODBCROWS} channel variable for SQL read
(SELECT) queries. To check out the backport of func_odbc and install it (which over-
writes the existing func_odbc.c file):
# cd /usr/src/
# svn co http://svncommunity.digium.com/svn/func_odbc/1.4 ./func_odbc-1.4
# cp func_odbc-1.4/func_odbc.c ./asterisk-1.4/funcs
# cp: overwrite `./asterisk-1.4/funcs/func_odbc.c'? y
# cd asterisk-1.4
# make install
The version described in this chapter works with a stock Asterisk 1.4 system, but the
backport (and Asterisk 1.6) will use the following syntax changes:
• read will become readsql
• write will become writesql
• dsn will become readhandle and writehandle (for separate read and write database
locations)

Getting Funky with func_odbc: Hot-Desking | 285