Hey Priyanka,
Check out
icm/HTTP/mod_<xx>
http://help.sap.com/saphelp_nw73/helpdata/en/48/49c7403a79350ce10000000a42189d/content.htm
URL Rewriting
http://help.sap.com/saphelp_nwesrce/helpdata/en/03/e301e249744a32adc6d23aff1f287c/content.htm
Regards
Andi