The ITS could not connect to the Web Application Server or the R3 sytem

After installing the ITS 6.20 I try to connect with

http://sapportal:80/scripts/wgate/webgui/! or /admin/! and I receive the message "The ITS could not connect to the Web Application Server or the R3 sytem".

Anybody could help me ? Could you send me the typically file global.srvc ?

Thank's in advanced