why my program dead?

I write 2 programs ,one is server ,ohter is client ,server have a servant and client have a servant too, server and client get the other side servant's proxy, use this proxy, invoke a function,

in the server , use a timer to call client's Proxy->function()
in the client , use a timer to call server's proxy->function()

when i faster this test, my server and client dead at the same time.

timer's interval is 100ms, Why?

Most likely the reason is that you run out of threads. You can increase the number of threads in the server thread pool with the property Ice.ThreadPool.Server.Size. The default is just one thread, which only allows one level of nesting.