Good morning folks

I have an issue that it's getting very important due to performance. We are deploying remote sites and due to this we place a firewall between the CallManager, and the remote sites, we've deployed 4 sites lately, however only 1 of these 4 sites has problems related to delay. when they go off hook they need to wait 3-4 seconds before they can actually place a call and/or wait 5-8 seconds before the call is routed.

do you please try to point me in the right direction

thank you