If the Internet provider does not directly support bundling, then multiple normal DSL connections can be coupled with a load balancer. First of all, the DSL accesses are set up for the necessary DSL ports. These are then coupled with a load-balancing table. This list assigns a virtual balancing connection (the connection that is entered into the routing table) to the other real DSL connections (bundle connections). Depending on the number of available DSL ports, several bundle connections can be assigned to one balancing connection.
With load balancing, decisions about the routing of data packets can no longer be made simply based on the IP addresses because the individual bundled DSL connections all have different IP addresses. Thus load balancing also considers the information in the firewall connection list. This list has an entry for every established TCP connection, and for load balancing the list is supplemented with information about the DSL port used.
