For a while now we have been looking for a way to bond several ADSL connections into one big pipe that can give individuals or corporates the ability to break the current limts of 4Mbps down and a up speed of 256kbps. However with Telkom's apparent short-sited purchase of DSLAMs that do not support the MLPPP protocol this has been impossible to do in the past or else Telkom has made it impossible.
There are relatively inexpensive options, with the many ADSL accounts options, to do load balancing across multiple ADSL lines that have been around for a while and if you have a lot of simultaneous users, as most business do, this is often a good solution. The cheapest option is to use Linux for your routing which give you a lot of cool features.
ADSL load balacing can also provide redundancy for Internet access by having one ADSL line from Telkom and another from Neotel so if Telkom's cable gets stolen you still have some form of Internet access even if it is reduced. Some of our clients also have an iBurst pay-as-you-go redundant connection that only get used if their ADSL lines go down. Being pay-as-you-go this is an inexpensive backup option as there is no mothly fee unless the line is actually used.
Recently we found a supplier that can provide us with the required MLPPP protocols needed on the DSLAM side to enable us to offer bonded ADSL solutions to customers! With this in place customer no longer need to go to expensive leased or diginet lines to get better throughput or to enable them to have decent uplink speeds to connect remote offices to head office.
The asynchronise nature of ADSL with its great download but poor upload speed has always made it difficult to do things like Virtual Private Networks (VPN) over ADSL because head-office can only send data at a rate of around 256kbps on ADSL, so as soon as remote users climbed on the VPN that paltry bandwidth has to be shared amoungst them all. By bonding up to 5 ADSL lines an upload speed of 2.5Mbps can be obtained making VPN's over ADSL for larger corporations possible.