At the end of SP-initiated SLO, how does SP knows where to redirect to ?

[Peter Schober]

* Adam Dong <adamdong at vidder.com> [2014-12-05 06:10]:
> For front-channel (redirect or post binding) approach, when IDP
> receives the SP-initiated SLO request, IDP sends (redirects) the SLO
> response to SP’s SingleLogOutService Location (correct ?).

No, the current IDP doesn't do any of that.
See the first sentence on the page
https://wiki.shibboleth.net/confluence/display/SHIB2/SLOIssues
-peter