[LibreQoS] routing protocols and daemons

dan dandenson at gmail.com
Wed Oct 26 18:35:03 EDT 2022

I have played with batman-adv quite a bit and there are some concepts in it
I really like.  Not being shortest path for one, and rating a link quality
instead of hard up/down.   I also like the layer2 model so it looks like a
big switch.  It's very clean from an operational perspective as it behaves
essentially like an MPLS/VPLS network administratively.

What I think we're missing is the integration of network attributes and
class of service.  For instance, user to 'internet' has 3 potential paths
with each having these end-to-end latency, upload throughput, download
throughput, and say 'quality' or packet loss.  Then having your QoS engine
able to tag packets for how it perceives them to need routed and then have
the routing engine pick routes based on availability.  So you might have a
longer path that will suffer some on latency because of the hops and link
type but has big bandwidth 'available' (ie large capacity and underused) so
it should ask for that flow to take the underused high capacity (and yet
still meets other criteria) path.  Something considered realtime might
prefer that 700Mbps licenced path that has lower and more predictable
latency and enough available capacity for the job. By encouraging high
throughput needs to take paths with a lot of availability and some
mechanism to prevent occilations from reroutes you could keep lower latency
links less busy and get load balancing by a more intelligent choice.    You
could also have some sort of reservation number tagged onto that packet to
ask the intermediate hops to reduce their available amount.  If you were
going to go all out on this and have devices that spoke this everywhere,
you could put your shapers everywhere as well, getting that desired egrees
shapping on both sides and letting the network sort of reserve a bit of
bandwidth for each customer based on that.

Of course this means scaling issues almost inherently because those
'available capacity' numbers and packet loss need to be communicated.
computationally intensive.

batman-adv does this in a way with it's OGM/ELP system.  You can take a
longer path through a batman-adv network because of a saturated link and it
doesn't consider that saturated link 'down'.

rflo was an interesting tech that did some of these once upon a time.

Just thoughts.

On Wed, Oct 26, 2022 at 3:38 PM Dave Taht via LibreQoS <
libreqos at lists.bufferbloat.net> wrote:

> On Wed, Oct 26, 2022 at 1:53 PM Herbert Wolverson via LibreQoS
> <libreqos at lists.bufferbloat.net> wrote:
> >
> > My name is Herbert, and I'm an OSPF addict... seriously, I love OSPF.
> Right down to stub sites, not-so-stubby sites, and isolating IP blocks
> within a site into "stub" nets and ensuring they are aggregated properly. I
> should probably go outside more...
> haha.
> My name is dave, and I think all routing protocols should have evolved
> much better to elegantly meet the real world problems they were trying
> to solve, than they have.
> To avoid burying the lede, to what extent does OSPF still rely on
> multicast? How well can it carry ipv6 now? What extensions are common
> in the real WISP world?
> BGP needs a few more napkins.
> RIP was a VERY good start but we drew the wrong lessons from its
> failures, and the super-duper-trendline towards centralized
> controllers inherent in OSPF and ISIS that happened in the 90s that
> doesn't scale anywhere near as I'd like.
> I liked the rise of meshy 802.11 networks, I know the author of AODV
> well (charlie perkins is arguably one of the fathers of mesh
> networking, far too few have read his books from the 90s). And I've
> been involved in the "battlemesh" group for many years with those
> trying to make 'em work better on networks such as guifi,
> wlan-slovinia, etc.
> Backstory. Back in 07, in Nicaragua, I was (stupidly) trying to get
> ipv6 to work over nanostation m2s or m5s I forget which, and the basic
> option was to run two copies of the ospf daemon to manage 4 and 6
> independently. I only had 32MB of memory and it didn't fit, so I
> started looking for alternatives, found babel, corresponded with (and
> frankly thoroughly annoyed) the author, and starting giving it a go.
> It transported 4 and 6 in the same packets, was tiny, was
> distance-vector (thus, I thought, more a match for bgp), and (to me)
> most importantly, solved the ipv4 and ipv6 routing problems in the
> same daemon at the same time, and actually fit into less memory than
> ospf did. It was good enough it seemed, to deploy to a few hundred
> routers without having to play major tricks with areas and stubs and
> so on.
> Babel is so simple that toke wrote a near complete implementation from
> the spec, in python, during a string of extremely boring IETF
> meetings, over the course of a week. He later took on the bird port.
> Over the years we've wedged most (but not all) of the key features I
> thought a meshy wireless routing protocol should have, with
> implementations in a standalone daemon, bird, and FRR. (there was a
> quagga port at one point too. I forget what happened to toke's python
> version).
> https://www.rfc-editor.org/rfc/rfc8966.html babel
> https://arxiv.org/abs/1403.0445 source specific routing
> https://datatracker.ietf.org/doc/rfc8967/ HMAC authentication
> https://datatracker.ietf.org/doc/html/draft-ietf-babel-rtt-extension-00
> RTT metric
> https://datatracker.ietf.org/meeting/99/materials/slides-99-babel-unicast-hellos-00.pdf
>  unicast hellos
> Missing is BFD support, and the slightest bit of traction outside of
> the shrinking battlemesh communities.
> Althea is using babel and fq_codel in their blockchain routing thing
> (I reserve comment), and I don't know where else, besides as part of
> wireguard tunnels, babel is being used today. But I'm rather
> interested in how OSPF evolved since I last touched it, and what use
> cases it is good at and fails at?
> > On Wed, Oct 26, 2022 at 3:29 PM Dave Taht via LibreQoS <
> libreqos at lists.bufferbloat.net> wrote:
> >>
> >> OK, since I'm getting such great updates on the state of the wisp
> >> world, far more in a few days than I've had in 10 years... and btw, no
> >> need to leap on dr science guy research questions like mine if you
> >> have like, towers flooding or the phone ringing off the hook....
> >>
> >> What routing protocols are in use nowadays? BGP, yes, and it seems
> >> ospf is popular?
> >>
> >> How about ISIS?
> >>
> >> I figure babel has zero traction or awareness despite being mandated
> >> by the ietf homenet working group.
> >>
> >> Secondly, do you rely on BGP based on the edge router or use it in
> >> software (frr? quagga? bird?). Using RPKI? Push FIBs anywhere? (route
> >> 666 in particular)
> >>
> >> Similar question related to the IGP protocol in use, where do you rely
> >> on it, vs all the tunnels you have, on what kinds of hardware?
> >>
> >> I note that robert at some point, somewhere, pointed out how fq_codel
> >> saved his bacon when there was a major routing mishap (as there is no
> >> congestion control in ospf), and I'd like to hear more of that story.
> >>
> >> BATMAN has been mentioned. There's other wireless protocols I've liked
> >> - OLSR for example...
> >>
> >> Nobody knows what lies underneath many consumer wireless meshes
> >> although it looks like 802.11s is a starting point, none, so far as I
> >> know interoperate across brands.
> >>
> >> --
> >> This song goes out to all the folk that thought Stadia would work:
> >>
> https://www.linkedin.com/posts/dtaht_the-mushroom-song-activity-6981366665607352320-FXtz
> >> Rip Van Winkle COO, TekLibre, LLC
> >> _______________________________________________
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> >
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> --
> This song goes out to all the folk that thought Stadia would work:
> https://www.linkedin.com/posts/dtaht_the-mushroom-song-activity-6981366665607352320-FXtz
> Dave Täht CEO, TekLibre, LLC
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