do you know how the asterisk is running ?
how many calls are processing,it's overloaded ,or no traffic at all ?
one sip device is registered to the asterisk or not ?
you cannot without this script. our scripts is leight-weight,no need to make your asterisk overloaded
you may also interested into flash version ,see http://allvoipsolutions.org/mydrupal/node/221
this simple scripts interworking with asterisk maangement interface to get active channels and reg status,and display on web ,it's php
you need config
manager.conf,a2billing.conf
REG STATUS
ACTIVE CALL LEFT PART
ACTIVE CALL RIGHT PART