>does it have any default queue size >attached to the link ? Vijay, The defaults are set in tcl/lib/ns-default.tcl. The default queue depth (line 73 in ns-2.1b7a, line 251 in ns-2.1b6, etc.): Queue set limit_ 50 Miroslav --- Dr. Miroslav. I. Klun Network Performance & Reliability Verizon Laboratories Waltham, MA 02451 (781)466-3830 [email protected]