What is the MTU?
The MTU is the “Maximum Transmission Unit” used by the TCP protocol. TCP stands for Transmission Control Prototcol. The MTU determines the size of packets used by TCP for each transmission of data. Too large of an MTU size may mean retransmissions if the packet encounters a router along its route that can’t handle that large a packet. Too small of an MTU size means relatively more overhead and more acknowledgements that have to be sent and handled. The MTU is rated in “octets” or groups of 8 bits. The so-called “official” internet standard MTU is 576, but the standard rating for ethernet is an MTU of 1500. When trying to decide what MTU is appropriate for your line, you must consider the type of connection you are using. For the purpose of this FAQ, we are going to consider only common cable and DSL MTU settings. Most cable and some DSL ISPs allow a standard 1500 octet MTU. In general, a 1500 MTU is what you would like to have since it works harmoniously with ethernet, but not all ISPs
