Hi there, the ultimate goal is to setup a Remote User Access model very much like VPN access from home to the office. This style of thought may be incorrect.

I have recently created a test environment to house LCS 2005 (Pool server), LCS Dir (Directory), & LCS AP (Access Proxy) which is located in the DMZ. The SIP internal DNS records are in place and functioning correctly. The Certificates type is Standalone, there are in place and working.
The Messenger 5.1 and Communicator are working fine within the AD and it has not affected the AD schema or Mail services, which is good.

However, I am unsure if I need to do the followining for a Remote User Access Model:

1. Publish a DNS SVR or DNS A record for a Access Proxy (for the Remote User Access model). The LCS 2005 documentation mentions that DNS records need to be configured for Federation, IM Public connectivety, and Proxy model. However, I am not planing to use a the later as the Remote Access model appears bets suited for the corporation.
2. How to configure the LCS AP server within a DMZ. That is, the LCS AP has one Nic card with one ip address. The doco states that there needs to be two NIC's. One facing the external world and the other pointing to the internal networ. This issue is more a conceptual understanding of how the LCS AP and Firewall are physically configured and setup. In addition, I use the Firewall to route all inbound SIP traffice to the LCS AP and then the LCS AP will re-route information to the LCS Dir server. That is the plan.
3 Does Messenger and Communicator use the "SIP:username@company.com" connection name (i.e. email address) to piggy back to my network.

If someone can please help me -it would be appreciated.

Thank You,

Troy Price