A multilink bundle is a collection of simultaneously opened bandwidth channels, including video and data links, that are coherently and logically controlled by preset commands. Links can be removed or added to the bundle when one Internet service provider (ISP) requests another ISP to do so. This process is known as link management.
A simple example of a multilink bundle is the use of two 64 Kbps channels to effect a 128 Kbps ISDN channel. A multilink bundle enables an ISP to offer users bandwidth-on-demand services, usually for a fee. By adding or removing channels, an ISP is able to change the available bandwidth. This may be done in response to changing line conditions or changing resource conditions.
The complexity of the system can be easily understood when one thinks of it this way: one system tells another when it is capable of combining multiple physical links into a single, logical link. This coordination of multiple independent channels between a fixed pair of systems provides a virtual link that produces greater bandwidth than any of the individual physical links.