To stay with your trusty TDM based PBX phone system or toss everything out in favor of a IP-Telephony phone system?

Why to miss services which would increase the value of the productivity?
Substitute it all for a brand new IP-Telephony phone system and take all the benefits this new technology offers.

What shall I do?

You have several choices:
- analog,
- digital, or
- IP phones
each desk and if to go with TDM or VoIP services to be linked with the external world. Some systems will even allow you to mix and match.

Which one to choose?
TDM?
VoIP?
or Both?
Why not?

Most any phone system that handles a few phone handsets will give you an option on how to connect phones to the PSTN or Public Switched Telephone Network.