Get User ID from Portal Environment

Hi,

In order to avoid creation of as many SAP backend users as our Portal Customers. We have created one SAP communication user and mapped it to LDAP roles & a similar LDAP user. The same user is configured in SICF for this ABAP webdynpro application.

Now following are my questions:

1- Is the above mentioned strategy is recommended or should be avoided? when & why

2- How can we get the portal customer id in ABAP webdynpro code

as we need to find which customer it is related to?

Thanx.