The CoDel queue management algorithm [LWN.net]

The CoDel queue management algorithm

Posted May 30, 2012 10:08 UTC (Wed) by nye (guest, #51576)
In reply to: The CoDel queue management algorithm by nix
Parent article: The CoDel queue management algorithm

>my existing bonded ADSL connection

Now we're *really* OT, but what are you using to do the bonding?

I was hoping to do that with a couple of Sangoma PCI ADSL2 modems, but in the small print it turned out that you can only do bonding with them if you're using PPPoE, and I don't know of any UK ISPs that offer that.

I've seen ADSL cards that can do it, but at that point you're better of just going to ADLS2 unless you're doing 4-way bonding or more, and I've seen expensive proprietary boxes that just sort it all out for you, but nothing affordable for an individual or small business.

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The CoDel queue management algorithm

Posted May 30, 2012 14:32 UTC (Wed) by nye (guest, #51576) [Link]

>Well http://compton.nu/2009/12/per-packet-load-balancing-with-... explains how I bonded four ADSL links with the same ISP.

Thank you for that link. I hope nobody minds the thread-hijacking to ask a little more about this - it's not a topic that seems to have much Google juice.

With that setup, do I understand correctly that - assuming the ISP has the bonding set up on their end - configuring the TEQL interface as you have will work regardless of the connection method used? It looks like it's actually very simple so long as you know the secret sauce.

What I'm not sure about is the IP addresses on the routers. You say that they need to support two different *LAN* addresses; how are the WAN ports configured? Are they bridged or do they need an additional address?

Say for the sake of example that you have a /29 netblock, giving you 6 addresses once you've accounted for the network and broadcast addresses. You use one that's shared between the routers and one for the teql0 interface, leaving 4 available for other machines. Is that correct?

Incidentally, would you recommend the Zyxel P-660 series? I do wonder if a better modem/router might solve my periodic loss of ADSL synchronisation, and while I've tried two different models, it's entirely plausible that they're both fairly intolerant of noisy lines.

The CoDel queue management algorithm

Posted May 30, 2012 14:50 UTC (Wed) by TomH (subscriber, #56149) [Link]

Those routers allow the LAN interface to be given up to two aliases in addition to their primary address.

So what I did was to set the primary address to a unique RFC1918 address, which was just used for management purposes when I needed to telnet to a specific router, and then to set the alias on each router to the same, shared, public address.

I then added static routes on each router to pass traffic for our public IPs back to the linux box where the bonding was done.

The WAN ports were configured with separate public addresses - a unique one for each router.

Bridge mode wasn't used - they were acting as normal routers.

I wouldn't like to say if the P660 is particularly good or bad - they were the free routers our ISP provided with the lines.

The CoDel queue management algorithm

Posted May 30, 2012 15:16 UTC (Wed) by nye (guest, #51576) [Link]

>The WAN ports were configured with separate public addresses - a unique one for each router.

Interesting, so this sounds like a different configuration than some bonding setups which appear to require only a single public IP address. I wonder if that's down to how the ISP configures their interfaces.

I suspect I could make a lot more progress here if experimentation didn't mean scheduling connection downtime of an unknown duration, which in practice means being physically present in a locked office building in the dead of night (for which honestly they Do Not Pay Me Enough™).

At any rate, thanks for the information.

The CoDel queue management algorithm

Posted May 31, 2012 11:21 UTC (Thu) by nix (subscriber, #2304) [Link]

The question really is, will any respondents to this question be using any ISP *other* than AAISP? They really do seem to be the only people who've tried to make line bonding work in any meaningful way, in the UK at least.

The CoDel queue management algorithm

Posted May 31, 2012 13:26 UTC (Thu) by james (subscriber, #1325) [Link]

This is going somewhat off-topic, but Eclipse do, although I haven't used it.

The CoDel queue management algorithm

Posted May 31, 2012 15:03 UTC (Thu) by nye (guest, #51576) [Link]

Entanet also offer a bonded option, and they're one of the wholesalers used by UKFSN.

The CoDel queue management algorithm

Posted May 31, 2012 11:20 UTC (Thu) by nix (subscriber, #2304) [Link]

All I'm using to bond is a multihop default route

ip route add default nexthop via 81.187.191.130 dev adsl weight 1 nexthop via 81.187.191.132 dev bdsl weight 1

to Zyxel P-660R ADSL routers that have no idea I'm bonding them, and two of Julian Anastasov's patches from http://www.ssi.bg/~ja/, to wit 00_static_routes-2.6.39-15.diff and 01_alt_routes-3.0-12.diff, to ensure that when one hop's routes go stale because of upstream problems we switch to the other. (I can't rely on normal 'when the link goes dead' bonding-driver stuff because the link that would go dead comes out of the router. I could fix this by using bridging, but Zyxel's documentation for that setup is so appalling that I haven't tried to make that work yet.)

However, I am lucky in that my ISP (AAISP) provides direct support for bonding on the ISP end: any packets sent to my public IPv4 or IPv6 address ranges will end up being evenly scattered between my lines (which fortunately are of similar speed, see the weight above). So all I have to handle is outbound routing.