Despite the ever increasing bandwidth of DSL connections, these remain the communications bottle-neck. In some cases it can be advisable to combine multiple DSL connections. There are a number of possibilities to realize this, some of which need active support from the Internet provider:
- DSL channel bundling (Multilink-PPPoE—MLPPPoE) The
availability of direct bundling depends on whether or not the carrier supports it. If available, the user has access to the sum of
the bandwidths of all of the bundled channels. Multilink-PPPoE can only be used to bundle PPP connections.
Note: This version of channel bundling provides bandwidths that are a multiple of the smallest bundled channel. This means that it is especially efficient when channels are all of the same bandwidth. The direct bundling of different bandwidths means that the channels with the higher data rates suffer from a loss in effective bandwidth.MLPPPoE bundles DSL channels just like MLPPP bundles ISDN channels (see ISDN channel bundling with MLPPP).
- Load balancing Load balancing dynamically divides TCP connections between independent DSL connections. The user has access to
the sum of the bandwidths of the bundled channels, although each individual TCP connection is limited to the bandwidth of the DSL
connection assigned to it.
Note: Unlike direct channel bundling, load balancing offers the true sum of all bundled bandwidths. This version is thus highly effective for combining different bandwidths. - Indirect bundling for LAN-LAN links With indirect bundling, a PPTP connection is established on each of the two or more
independent DSL connections. These PPTP connections are then bundled. For LAN-LAN links at least, genuine channel bundling is
possible over the Internet even if the Internet provider itself does not offer channel bundling.
