[ns] How to deal with "Unable to alloc %d bytes"

[=?gbk?B?1cXRx/at?=]

hi, all!
  
 Enviroment: Windows Server 2003 + Cygwin, 4GB memory
  
 I am simulating a P2P application for scalability. when the number of nodes increases to over 3000, the application always shows "Unable to alloc %d bytes" after running a few minutes. As far as I observed, the application took up about 1GB memory.
  
 Is there some one in the same situation and how to deal with it? Is it a ns2 bug?
  
 Thanks and Best Wishes.
 Kimi Zhang