[K12OSN] OT: Using multiple DSL connections

Tim Nelson tnelson at rockbochs.com
Thu Jan 31 15:06:43 UTC 2008

You may want to look at another open source project called pfSense. It is a router/firewall platform that you can run on embedded hardware or even an old server/pc you have lying around. One of its greatest features is the abiliity to load balance multiple WAN links. Keep in mind if you have two 3Mbit pipes, you will not get 6Mbit throughput, but rather, outbound connections will be sent out one pipe or another based upon state or bandwidth usage. You can even assign your VoIP traffic priority over other traffic using the built in traffic shaper.

The project is -VERY- active with an imminent 1.2 stable release just around the corner. Support is second to none in the forums, mailing lists, and their paid commercial support.


Tim Nelson
Systems/Network Support
Rockbochs Inc.

----- Original Message -----
From: "Peter Scheie" <peter at scheie.homedns.org>
To: "Support list for open source software in schools." <k12osn at redhat.com>
Sent: Thursday, January 31, 2008 8:00:09 AM (GMT-0600) America/Chicago
Subject: [K12OSN] OT: Using multiple DSL connections

I have a client site where we've installed K12LTSP-5EL with a single gig NIC, 
connected to a switch (which in turn has another switch daisy chained off it via 
gigabit connection).  The clients all have 100Mb connections.  The clients are a 
mix of thins, Windows, and Macs.  They have Vonage phones, which according to my 
reading, each require about 90K of bandwidth.  I think they have 4-6 such phones 
now and anticipate adding more, although I don't know what the upper limit is yet.

Because of the bandwidth requirements of the Vonage phones, and anticipated 
growth in the number of phones, they have installed two DSL lines.  I have not 
had a chance to test the lines to see what kind of bandwidth, up & down, they 
each provide.  As it stands right now, the LTSP server provides DHCP, but points 
to only one of the two DSL bridges as the default gateway.  IOW, at the moment, 
the second DSL line isn't being utilized.

My question is whether anyone has any suggestions about how to 
utilize/share/combine the bandwidth of both DSL lines so that all computers and 
all phones can make use of either/both lines.  I could put the phones onto a 
separate physical network and confine phones to one DSL line and the computers 
to the other, but that seems inefficient and inflexible, and it means they will 
have to make sure they pay attention to which network they plug into (which they 
won't understand and therefore will do incorrectly).  Depending on the time of 
day, computer traffic will decline as phone traffic increases, and vice-versa, 
although the nature of their respective traffic patterns is different (i.e., 
computer traffic tends to be bursty).  What I'd really like is to setup a 
dedicated linux box to act as the gateway for the network, put three NICs in it, 
one for the internal network and one for each DSL line, and have it load 
balance/round robin the traffic between the DSL lines.  Any suggestions?


K12OSN mailing list
K12OSN at redhat.com
For more info see <http://www.k12os.org>

More information about the K12OSN mailing list