How to relate a token based ISG session to its icx_session.session_id (which is created while genera

Authentication for restful services :

  1. Using Basic Auth made a call to "AuthenticationService" WADL login service. Which would create a ICX_SESSION in DB and returns a token (icx_sessions.xsid).

  2. Using same token, make any number of subsequent calls to ISG from custom web application client server.

From the DB session established from step 2 (using the token), I want to relate current session to its parent ixc_session that created the original token (session_id created from Step 1).

All session connections made to Oracle DB using token, have same session_id (fnd_global.session_id). Looks like DB is pooling the session id from a list of sessions available v$session.