________________________________ From: Dinh, Tuan (ICT Centre, Marsfield) Sent: Thursday, 17 December 2009 11:16 AM To: 'ns-users@isi.edu' Subject: VoIP over IEEE 802.11 simulation scenarios Dear ns-users, What I about to enquire maybe the old concept but I have tried to search around but couldnt find the answer. The question is how to simulate the VoIP traffic in the WLAN infrastructure mode in term of scenario? ( For example, I want to have 4 mobile nodes (clients) to send VoIP traffic (UDP packets 60 bytes/ 20ms) to the other and all the traffic must be reach the AP first, AP acts like the bridge). ( node 0 is AP, node 1 sends udp packets to node 2 and vice versa, node 3 sends udp packets to node 4 and vice versa - basically there are 2 calls going on) Initially, I made use the code in ns example folder (~ns-2.34/tcl/ex/802.11/infra.tcl). The routing protocol used is DumbAgent. Later on, one of my colleague suggested that the nodes will connect direct to the other and not through AP if I use this scenario, and she suggested another scenario that all the sinks [Agent/Null] should be placed at the AP (node_0) and all the traffic send direct to them. It appears to me that scenario worries only the uplink but not downlink. Please let me know your thoughts Best regards, Tuan