Michael Judd setup an asterisk system for adempiere community to use. once the accounts for people are created you can access it using a voip softphone or a hard phone.

With the service we can currently conference, and call extensions for free. Mike have the servers located in data centre in London which has plenty of bandwidth. (1,000GB/month) he has some inbound UK numbers which can be routed through different call groups and queues. You can schedule timezones and only route to certain extensions at certain times of the day (so as not to wake you up at night).

Currently, there is no outbound calling (as that costs money), but he can add additional telephone numbers for different countries and route them directly to you.

People who want to join the system will be able to call and transfer calls to each other – so this could be used as a collaboration tool for support.

Mike is presently looking for other interested parties to try this out – please contact michael dot judd at akunagroup dot com if you are interested.

I have tested it using Ekiga on 256 Kbps bandwidth from Airtel Broadband services , it works well some screen shots below

account settings i have done in Ekiga

service:
username:
password: (same for voicemail)

You can try the following numbers:
102 – Mike Judd
304 – Satyag
# – Directory
*43 – echo test
*60 – speaking clock
411 – Directory dial by name
*97 – voicemail

You can try other sip clients from this Sip software list and report to mike how things are working at your end