[Asterisk-Users] three way call using sip

[Philipp von Klitzing]

Hi!

> According to this only the BT102D supports "conferencing" aka 3-way 
> calling:
> http://www.grandstream.com/Product_Spec.pdf

This is vaporware, the product was cancelled. Anyway, with a recent 
firmware you can do attended transfers with the BudgeTone, but no phone 
based 3-person-conferencing.

Cheers, Philipp