We recently purchased a ShoreTel SA-100 appliance which would allow us to arrange audio and web conferences, instant message and even screen share presentations, applications or entire desktops.
We just couldn't get the screen sharing part to work. We installed the presenter software that was required and ensured we were running a compatible web browser, but kept getting the below error.
I logged a call with our ShoreTel and Firewall/Proxy support desks but both were also puzzled by the issue and unable to provide further assistance.
After running and comparing Wireshark traces between it working (without proxy settings) and not working (with proxy settings), I could see our DNS servers responding with 'Server failure' when looking for an A record 'proxy' (proxy is the name of the proxy server as specified in the browsers proxy settings)
Eventually, after more troubleshooting and testing, I managed to get it working by doing the following:
1) In the internet browser settings, I changed the proxy server to the FQDN. (i.e BEFORE: proxy AFTER: proxy.domain.com)
Conclusion: VPresent software requires FQDN or IP address of proxy. Very strange as we have no other proxy server issues by just specifying 'proxy'
I updated the proxy server name to all machines on the network using group policy.