This is the default load balancing algorithm. Ericsson Cradlepoint endpoints do not perform aggregate, channel-bonded load balancing. Ericsson Cradlepoint endpoints attempt to balance modem usage based on the available bandwidth on the attached load-balanced modems. However, the Ericsson Cradlepoint endpoint does not sum the available bandwidths of attached, load-balanced modems and summed bandwidth is not available in online speed tests.
Each modem attached to a load-balanced endpoint has an associated bandwidth value. For example, consider two modems in an endpoint, modem A and modem B. In this example, modem A has an available bandwidth of 1 Mbps and modem B has an available bandwidth of 2 Mbps.
When an IP connection (session) is made from a client device attached to the endpoint, the endpoint checks the available bandwidth of each of its modems. The connection is placed on the modem with the greatest available bandwidth; in this example, modem B. The amount of remaining bandwidth on modem B is recalculated by subtracting the bandwidth required for the connection from modem B's initial bandwidth.
As new IP connections (sessions) are made from client devices, the endpoint again checks modem A and modem B for available bandwidth. If modem B still has more available bandwidth than modem A, then modem B is used for the new IP connections until the connections are terminated. The available bandwidth of each modem is checked each time new IP connections are made. Modem A won't be used until it has greater available bandwidth than modem B.
Based on the above example, we can see that the attached load-balanced modems are not used evenly. The available bandwidth of the modems is also not summed. This issue compounds when there is a large difference in the available bandwidth of the two attached modems. To continue the example, imagine if Modem B was an attached 4G modem, and Modem A was an attached 3G modem. Modem A, the 3G modem, may be only slightly used (or possibly not used at all) depending on the volume of IP connections made from attached client devices. Of course, this would not affect protocols like BitTorrent, which typically use both modems very well due to the high volume of individual IP connections spawned while a torrent is downloading.