Hi Jeff,
Thank you so much for replying. What we have noticed is that the IP based dialers should be able to handle 100-120 people each but if we have more than 25 combined we get call quality and network connectivity issues that affect even remote sites. If the volume of calls increase the internal web servers slow down so much it make agents wait between screens. If we exceed 30-35 users the mitel pbx which is hosted outside of the firewall but on the same network will even start to drop calls and decrease in call quality.
Hope this helps on understanding the issue we are having. Again thank you for your reply. Much Appreciated!