You wish to proxy Microsoft Lync through the Symantec Web Gateway, but connections are timing out.

Microsoft Lync utilizes an OCSP response-signing certificate mechanism, and will not accept requests from uncertified hosts. The SWG does not support this process and is unable to complete the connection which subsequently times out.

Use a proxy exemption or a PAC file to direct Microsoft Lync traffic away from the proxy so that it accesses the Internet directly.