Cephas

Another consideration is whether you have IP hardphones on any of your systems. If you do, or might in the future, I urge you to ensure the same codec will be used across the board. Since IP hardphones support only a small sample of the codecs the IPO offers, choose accordingly. Ie don't pick G.729 simple, but rather go for G.729(a)

Or G.711 if you can afford the bandwidth on your WAN :-)

Peter