I found tons of links for Lync and proxy/ISA, but none for the client.

We have Lync server running fine from inside and outside the network.

We had this issue when invited to another company's meeting via Lync.

We block outbound http at out firewall and use a (not inline) ISA 2006 proxy server for internet access.

Here are the symptoms:

Could not connect to vendor's server.
I opend a hole for one PC to access all http/s. (not acceptable)
After the meeting, I went on to test other options.
Reset firewall back to block and added vendor.com domain to ISA allowed without auth list.
Lync client connected fine.
removed the previous and added vendor.com domain to ISA allowed with NTLM auth list.
Lync client could not connect. (No NTLM?)

I do not want to add every external company that might invite us to a meeting to our ISA allowed without auth list. (this would only be requested after a meeting started and failed, not acceptable)

I tried logging the previous attempts, thinking that I could make a rule to the Lync "user agent", but that shows up blank in the ISA logs.

How are other getting their Lync clients to fconnect to other companies meetings when using a proxy server?

 

 

 

 

• Edited by StevenBerkHolz Friday, September 16, 2011 11:33 AM