TDM is a multiplexing technology that guarantees each port a fixed amount of bandwidth on a rotating basis. TDM is suited to constant-bit-rate traffic. TDM combines many digital bit streams with relatively low bit rates into a single bit stream with a relatively high bit rate. It is, in essence, a way for many slow communications channels to “timeshare” a very fast channel. The advantage is that the cost per bit transmitted on a single fast channel is lower than on multiple slower channels. TDM is accomplished by simply interleaving data from several bit streams. This can be done on a bit basis or byte basis, called “bit interleaving” or “byte interleaving,” respectively.