For the past ten-plus years enterprises have been making the switch from TDM to IP telephony. For the most part, this involved replacing older digital telephones with their IP equivalents and converting applications such as voice mail and voice response units to a SIP interface. The benefits of these conversions are significant and you would be hard pressed to find a new PBX without an IP infrastructure.
In my latest article for No Jitter, I write about the history of fax before discussing two ways of moving this old, analog technology into the world of IP communications.
Tao, Zen, and Tomorrow 
Hi Andrew,
I clicked on the article link and got the following error:
“Page not found
The requested page “/post/240170004/from-tdm-to-sip-how-does-foip-fit-in” could not be found.
”
Can you please check.
Thanks,
Akash
There is a problem at No Jitter where old articles are not showing up. They are working on a fix. Stay tuned.