Although Layer2 Line bonding has been used extensively in the past by many ISPs, the line bonding technology at Layer 3 (network layer) is a more modern concept which appeared just recently. The advantage of the bandwidth aggregation of multiple physical mediums at this level provides greater flexibility , higher speeds and lower implementation costs.

In terms of flexibility, the bandwidth aggregation at layer 3 may be carried out without any coordination with the ISPs while allowing the utilization of alternative media such as the air (wireless broadband connections and 3G,4G cellular networks) which allows the provision of professional high-speed connections even in places outside urban areas with inadequate telecommunications infrastructure. This technology can also be used to combine different means and providers to achieve even higher reliability.

The cost of implementing the leased circuit via layer 2 line bonding technology requires specialized equipment to the customer premises and the DSLAM. The equipment at the customer premises is much more expensive than conventional ADSL modems and the DSLAM equipment, apart from the purchase and maintenance costs, needs to be hosted at a reserved space in the DSLAM which has a high monthly rental cost. The broadband bonding technology in layer 3 has a similar equipment cost due to the higher throughput, but can be implemented in software level and deployed in a virtual appliance. The second end to be used for the bandwidth aggregation is not required to be hosted in the DSLAM, but to any data center worldwide. The cost of renting space in the Data center is much lower than that of the DSLAM.

Everything indicates that the layer 3 bonding is already here and has all the elements to prevail.