WAN link Load balancing

WAN link Load balancing is a session-based process of directing Internet traffic among multiple, and varied network connections. It requires a single WAN link controller located at the main site located between gateway modems/routers and the internal network, and intelligently load balances and provides failover for both inbound and outbound traffic among the network connections. Assuming there are two ISP connections, both network connections can be used at the same time. The benefit here is that you don’t pay for bandwidth that is only used as a backup for when an outage occurs. For example, traffic will go through network connection one. If the WAN link controller detects that connection one is over taxed or failed it will direct users across the second ISP connection. Intelligent WAN link controllers will continuously spread the traffic across the network connections based on the available resources. For example, with two T1s, it will not wait until the first T1 is over utilized before sending traffic out the second WAN, it will make use of both lines evenly. Having two 1.5Mbps network connections does not mean that users have 3Mbps of bandwidth available to them. You would have 3Mbps available, but not for a single session. In other words, you would have 3Mbps of available bandwidth, but only 1.5 of throughput could be dedicated to any individual session. A single session will still only have 1.5Mbps of throughput, as with WAN link Load balancing, each user can use only one ISP connection at a time.

Site-to-site channel bonding

Site-to-site channel bonding is a form of WAN link load balancing with a different approach that can increase the total combined network bandwidth of multiple network connections between two locations. This approach requires a WAN link controller at the main site and also at the remote site. Unlike WAN link load balancing, site-to-site channel bonding conducts continuous health checks (up and down status) of the network connections using, and uses packet-based load balancing to distribute traffic across all network connections. However, with site-to-site channel bonding, two 1.5Mbps network connections will equal approximately 3Mbps, providing all traffic with the combined throughput from the multiple network connections.