[Nel] newbies about packet schema

Sat, 3 Mar 2001 02:02:34 -0800

> I have read artice for winsock program, if folling article is
+> true, that snow ball netowrk driver , should change it's packet
+> schema.  any one can give me suggect ?
+
+I am not familiar with the snowball protocol ("packet schema").
+However, I assure you that the article is correct --- attempting
+to turn TCP from a byte stream into a sequenced message stream by
+disabling Nagle will not work.  The only way to implement message
+semantics on top of TCP is to add your own packetization to the
+byte stream.  For example,
+
+
+  void SendMessage( int socket, const void * buf, size_t length ) 
+  {
+    long l = htonl( length );
+    write( socket, &l, 4 );
+    write( socket, buf, length );
+  }
+
+  void RecvMessage( int socket, void * buf, size_t * length ) 
+  {
+    long l;
+    read( socket, &l, 4 );
+    l = ntohl( l );
+    assert( l < *length );
+    *length = l;
+    read( socket, buf, length );
+  }
+
+
+-Ken
+
+Kenneth J. Duda
+Stanford University Distributed Systems Group
+<kjd@cs.stanford.edu>
+
+
+