[asterisk-users] Best PBX for Call Centers?

[Tarek Sawah]

Hello List,
I have customer with a 40 Agents call center. and is looking to install a PBX switch that can serve those agents.
As per my experience i suggested Asterisk as i have tested it with Call Centers, however he has been advised not to use it although his provider is using Asterisk to send him calls. He has been advised to use Sippy which they claim is more stable than Asterisk. 
i'm not an expert with Sippy so i'm looking for a piece of an advise here.. if i'm doing an Asterisk Vs Sippy comparison. can anyone help?
Regards



Tarek Sawah

Information Technology  Adviser

Integrated Digital Systems

CCNP, MCSE, RHCE, TELECOM

USA: +1 386 492 9993