[sllug-members]: Multiple DSL Lines

[Mac Newbold]

Today at 4:41pm, Corey Edwards said:

> On Tue, 2006-12-12 at 16:06 -0700, Adam Barrett wrote:
>> Has anyone here had experience in support multiple DSL lines?
>
> Yes. I have one location which has 11 DSL lines and we're trying to get
> 4 more added.

Wow.

>> I am looking at getting a second line and using a Linksys RV042 with
>> dual WAN connect to get a second line.

I'm in a similar situation, and even looked at the same hardware. Our 
problem is up and down though - we're stuck in in a building that can't 
get faster than 1.5Mbit DSL.

>> Would doing this help my upload speeds? That is the real crunch I am
>> in, I am capped at 768K and I am hitting it.
>
> That should work just fine as long as the DSL lines are from the same
> ISP. With upload traffic, your router gets to decide which interface to
> send packets out on so it can do whatever kind of load balancing you
> want. The reason to use the same ISP is that many (hopefully most, but
> unfortunately not all) will refused to send out packets from an IP
> address that shouldn't be on their network. They do that to prevent DOS
> attacks mainly, but it's just good practice in general.

One thing to note is that since they're not "bonded", they'll have 
different IP addresses on the other end, and so traffic on a TCP 
connection for example will most likely come back to the same IP it came 
from. If you're running a server behind it, your DNS will point at only 
one of the two incoming IPs generally, so all the incoming will hit the 
same line. Each connection, once started, will be tied to a particular 
line, and no connection will be able to use both lines. So if you're 
trying to do a single really big upload or download, you'll still see the 
same performance you do now on that transfer. But any other transfers will 
see much better performance unless they're already tied to that same link. 
Anything starting up after the one link is tied up will generally use the 
other (unless it is an incoming connection, in which case the balancer 
won't have a say in it).

> Qwest will be happy to supply you with more DSL lines, as long as they
> have facilities. For your two that shouldn't be an issue because you
> probably have two phone lines coming into the building.
>
> So yeah, it should be possible. To load balance incoming traffic you'd
> need an ISP with a real clue. It would help in this case too, but you
> can probably get away with it without.

AFIAK, XMission qualifies on that account. I've seen them work with people 
who wanted multiple lines for redundancy, and helped them get set up with 
BGP and stuff so they can have their own AS and do real routing, and have 
their address block advertised on both ends.

Thanks (and thanks in advance) to anyone who contributes to this thread! 
I'm very interested in the possibilities. Adam, I hope you'll let us all 
know how it goes if/when you set this up.

Thanks,
Mac

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Mac Newbold		MNE - Mac Newbold Enterprises, LLC
mac at macnewbold.com	http://www.macnewbold.com/