You are looking to get a translation? Its not that difficult.
[VB]
Private Sub StartServer()
Dim server As New TcpListener(IPAddress.Any, 1234)
server.Start()
Dim socket As Socket
Dim chatSession As ChatSession
While True
blocks until a connection is established
socket = server.AcceptSocket()
when this fires the socket will be connected and the connection
will actually be setup on a port other than 1234. this allows
us to keep servicing future requests on port 1234.
for long running processes, the key is to somehow pass the socket
off to another thread. if you dont do this the server will
not be able to establish new connections while the process is still
running.
chatSession = New ChatSession(socket)
chatSessions.Add(chatSession)
End While
End Sub
[/VB]
There is a sticky thread to help with C#->VB translation.