Multilink Operations

Figure 2-5 Multilink Operation

The Multilink Protocol (MLP) lets you use more than one physical connection to make a single logical connection. This increases the amount of bandwidth available between the DTE and DCE improving response times and increasing traffic levels. An MLP connection does not provide a multiple channel end to end connection to remote DTEs. Not all of the DTEs attached to the PSDN need to use MLP and not all DTEs need to use the same number of physical connections.

The internal structure of X.25 when using MLP is shown below:

Figure 2-6 Internal Structure of X.25 When Using MLP

MLP frames have two additional octets placed between the control octet and the data. These octets enable each frame to have a sequence number so that it can be reassembled in the correct order at the receiving end. The two extra octets are not present in the standard datalink frame shown in Figure 2-4.