Multiplexing multiple WAN links for traffic aggregation has been a
problem that dogged me
for nearly 3 years or more.
I remember building a custom hardware for TalentPro in Venkatanarayana
road lugging a heavy
gear with 4 NICs and trying to do ISP failover with two Airtel 2MBPS
connections trying to get
an aggregate 4 MBPS.
I also went to the Airtel office nearby in Ramana enclave(not sure)
just 4 complexes away to
see whether they could give me some configuration access to their POP
when traffic leaves to the
Internet.
Well that was I think more than 4 years ago.
I actually did WAN multiplexing with 2 wireless links for two clients
Brovis and net4in near
Irungatukotai. That was I think around 3 years ago.
But my failures are more.
I tried this technology in Leatherlink Sivakumar's office and I think
nothing came out of it.
Recently less than a year ago I also tried this tech in a location in Bangalore.
Failures, failures and more failures.
And I have also communicated to LUG about several possibilities to achieve this.
But last night(around 10:30 or so) I saw a youtube video that
clarified a lot of things to me.
https://www.youtube.com/watch?v=XIeXAqdbpzI
But I cannot apply this knowledge directly and most of you will not
follow this video.
You require background knowledge.
To put the whole story in short, basically you get true channel bonding through
VPN aggregation using a remote site with multiple IP addresses
terminating on the same machine.
Then what you do is setup multiple static routes and route packets
through multiple ISP WAN links and
then you have to bundle them together.
So for example, if you have 3 WAN links then you need 3 IP
addresses(public) in the remote VPS node.
Then you setup 3 different OpenVPN VPN connections using the 3 WAN
links to terminate on the 3 IP addresses
which will create 3 different tap interfaces on the remote VPN/VPS node.
Then on both sides you have to bundle together these 3 VPN interfaces
into one virtual interface and then assign
an IP address here and an IP address there.
So in the OpenVPN private address space you assign a local IP for the
interface bundle on one side(client side at our
location) and on the server side at the VPS node. Then you set the
default gateway of the remote bundle IP
to the local network at our premises.
Then we are done!
Now you will get full real traffic aggregation giving you the real sum
of the bandwidths offered by the links in both directions.
If you have total of 4 MPBS down and 2 MBPS up you will get exactly that.
Really cool.
I am yet to test this.
You do this differently on Linux and OpenBSD.
But the idea is the same.
I going to try this and release an open source project for the same.
http://wanbundle.sf.net
-Girish
--
Gayatri Hitech
http://gayatri-hitech.com