WE are installing an Avaya IP solution for a customer, We have a primary gateway at the main location with LSP mode Media server and Media gateways at remote locations. The remote Avaya G350 media Gateways register with the primary controller and use the H.248 protocol. The Avaya IP hard and softphones register locally at the main site with the H.323 gatekeeper. However the IP hard and Softphones at the remote sites do not register with the primary controller/H.323 gatekeeper. The secure VPN tunnel has been established via a 512K ADSL link at remote sites and leased lines from ISP to main location with ISA 2004 servers at either remote sites and the main site. My question is: is there any configuration on the ISA servers that can be preventing the H.225 and H.323 protocols through that are required for the registration of the Avaya IP phones?