All students of The SIP School that purchase access to the SSCA® SIP training program are allocated a free sip address that belongs to a private domain, @thesipschool.com and it is our great partner, OnSIP that provides the back end services that make this work.
To date, there are over 18,000 sip addresses allocated to students and well over 10,000 minutes worth of test calls that have been made by these students.
OnSIP provides a whole suite of services that include Phone System Hosting, SIP trunks, Desktop and Mobile applications. You can find out a lot more by visiting their main page.