Windows Server® 2008 TCP/IP Protocols and Services

Small Segments

A small segment is a TCP segment that is smaller than the MSS. To increase the efficiency of sending data, TCP avoids sending and receiving small segments by using the Nagle algorithm and by avoiding silly window syndrome.

The Nagle Algorithm

For interactive data, such as the data of a Telnet or Rlogin session, much of the traffic is made up of individual keystrokes sent by the client and echoed by the server. For each keystroke, a single byte of data is sent. This is a network efficiency of 2.5 percent (the number of bytes of data [1 byte] divided by the number of bytes of overhead needed to send the data [40 bytes]). For interactive sessions, such as Telnet, each typed character must be sent and echoed back to the Telnet client ...