How exactly can a load balancing router improve the performance & reliability of consumer broadband connections ?

A broadband connection can encounter a networking or cable fault anywhere within the campus or outside (fiber or cable damage outside APR) which is beyond the control of any subscriber. If it happens it may take a day (or more) also to fix at times. If you think you have a critical requirement like work-from-home which you cannot afford to compromise on, then its is better to dedicate a secondary backup internet connection. Their are three types of policies that are typically used with load balancing routers:

Case 1 - Active Standby Model

Here one of your connections is always designated as the primary (It could be a fast FTTH connection) while the secondary is designated as secondary (It could be slower and cheaper ADSL, 3G/4G Mobile Broadband or just a cheaper FTTH connection). We expect the fault in the primary connection to be intermittent and random and this topology will help overcome the temporary outage. And the transitions are transparent to the user (i.e. handled entirely by the LB router)

Case 2 - Round Robin Load balancing

This can be used if your primary connection is unreliable. In this case you can buy two high speed connections and load balance round robin (weighted or unweighted) through them If one of them goes down, your application still work through the backup without any observable degradation in performance. This is very popular in enterprise environment to connect two branch offices or by data centers.

Another use case is to increase Internet speed. The max speed at APR is now 100 mbps (supported by both Airtel and ACT). Let say you want a 200 mbps connection for some reason (including bragging rights). This will satisfy your need (but make sure you have a GbE router not fast Ethernet one)  You can add another 50 Mbps using Pursuit Edigital Internet service a LB router with 3 WAN ports if that's what you are after ;-))

Case 3 - On Demand

If you ISP supports 40 Mbps and 100 Mbps connection speeds but not 60 Mbps, then this is what you can go for. Use the 40 mbps connection as primary and another 20 Mbps from other Service provider, then the 2nd interface can be used if the first hits its peak speed. Maybe especially attractive if you have a good plan on pay per use on the secondary connection.

In the interest of Reliability and network fault tolerance, I do not recommend taking two connection from same ISP. Its very rare that only your one connection will go down. Generally a network fault (more common) will impact an entire complex or area for a particular ISP. So if you take both connection from same ISP, you may find that both yor connections are down together at same time defeating the reliability requirement entirely and frequently.

- Suman Kumar Luthra @ APRC-P3 Telecom Sub-Committee