Yes! You can specify the delay, bandwidth, and packet loss rate between any two nodes in your topology. Bandwidth and delay are specified in the NS duplex-link statement, while packet loss rate is specified with the Emulab tb-set-link-loss extension to NS. You may also specify delay, bandwidth, and packet loss rate between nodes in a regular LAN.

Please see the Extensions page for a summary of all Emulab NS extensions, and the Emulab Tutorial for an example.