To use a proxy server in your connector setup, you need to provide the server details in the config.xml file for the Quality Center - Project Tracker connector, or the .conf files for the Quality Center - TeamForge connector.
# Java Additional Parameters wrapper.java.additional.1=-Dlog4j.configuration=file:..\..\..\lib\log4j.xml . . < existing settings> . wrapper.java.additional.6=-Dhttp.proxyHost=192.168.1.10 wrapper.java.additional.7=-Dhttp.proxyPort=8118