Dear All, I am trying to simulate SIP protocol in a Wired-cum-Wireless and MobileIP network. After compiled the Rui prior SIP patch successfully in ns-2.27, I have tried a simple wired network example and it worked. However, when I introduce some wireless nodes running SIP on it and connected via a base station with wired network in the simulation. I got errors like: "Segmentation Fault!" I did not meet this error in wired network, so I think maybe because of wireless nodes in this simulation or some undefined class in some part of this simulation. I have no idea which part of the script lead to this error. What do you guys think of this problem? Can you suggest me where I should go to check and fix this problem in NS-2? It's so important for me. please help me. with thanks: Fahimeh Akbari fahimeh...@yahoo.com