System information

to or from the CO, either Asterisk will deliver calls from the PRI through itself and to
the existing PBX, or the existing PBX will send calls over the PRI connection to Asterisk,
which will then direct the calls to the new endpoints (phones).
With Asterisk in the picture, functionality can be moved piecemeal from the existing
PBX system over to Asterisk, which can take on a greater role and command more of
the system over time. Eventually the existing PBX system may simply be used as a
method for sending calls to the existing handsets on the agents’ desks, with those being
phased out over time and replaced with SIP-based phones, as the wiring is installed and
phones are purchased.
By adding Asterisk to the existing system, we gain a new set of functionality and ad-
vantages, such as:
• Support for remote employees: calls are delivered over the existing Internet
connection
• Features such as conferencing and voicemail (with the possibility of users being
notified via email of new messages)
• Expanded phone lines using VoIP, and a reduction in long-distance costs
Such a system still suffers from a few disadvantages, as all the hardware needs to reside
at the call center facility, and we’re still restricted to using (relatively) expensive hard-
ware in the Asterisk system for connecting to the traditional PBX. We’re moving in the
right direction, though, and with the Asterisk system in place we can start the migration
Figure 22-2. Remote hybrid system
Hybrid Systems | 491