Which permissions does a customer need to log in?

Jens Kisters __SeibertSolutions

This question is in reference to Atlassian Documentation: JIRA Service Desk permissions

I put a user in the group "jira-servicedesk-users" but when i try to log in to the service portal i get 

"You do not have a permission to log in. If you think this is incorrect, please contact your JIRA administrators."

I can log in to JIRA, but i want to have it the other way around: Portal Login: Yes, JIRA Login: No

Jens Kisters __SeibertSolutions

I got it. 

The portal users must not be in any of the application groups (such as "jira-servicedesk-users"),

but they must have the project role "Service Desk Customers" for at least one project