

A Radical New Router - TriinT
http://www.spectrum.ieee.org/computing/networks/a-radical-new-router

======
patrickg-zill
This is more like an ad than an article. Flow-based routers have been
developed in the past, and the reason they are not prevalent is due to
performance issues of one kind or another.

If they truly have solved the problem(s) that other flow-based routers had,
great, but this can only be determined in the real world.

------
hendler
I think it's faster for flow control and packet filtering, not just faster in
general.

The illustration states that P2P traffic is problem to be solved by this
router. Article also states: "How Flow Routing Works

Flow managers keep track of streams of packets and can protect voice and video
transmissions while reducing peer-to-peer traffic."

"Worse, peer-to-peer (P2P) services, used to download movies and other large
files, are eating more and more bandwidth. P2P participants may constitute
only 5 percent of the users in some networks, while consuming 75 percent of
the bandwidth."

Also seems like this would make tiered internet easier in general. Doesn't
this router have big implications on the Net Neutrality debate?

~~~
extension
Tiered access requires particular connections to be _statically_ limited. That
is already easy to do. This device applies limits dynamically based on
throughput and duration, which seems pretty fair and neutral to me.

What I don't understand is how it distinguishes between audio/video streams
and P2P traffic. I would think them pretty similar without inspecting packets.

~~~
lil_cain
Number of streams/user would give you a fair chance of telling which is which
for most users.

------
ghshephard
It would have been appreciated if the author could have compared his
technology against CEF+CBQ. Suggesting that routers process switch each packet
and don't treat different classes of traffic differently when avoiding
congestion with packet drops is like suggesting we divide IP spaces using
classful addressing. True in 1993, but...

See: <http://en.wikipedia.org/wiki/Cisco_Express_Forwarding> See:
<http://en.wikipedia.org/wiki/Quality_of_service>

------
iigs
It annoys me when router vendors (Cisco, looking at you) advertise their
throughput as theoretical maximum bi-directional. Almost no real network
design can take advantage of that speed. If this router only has 4x10g port
(the two left cards), for all intents and purposes it's a 40-50gbit router.
That's probably a great deal in the $50-100k range, though, so there's still a
place for it.

I feel like I'm telling Larry Wall what is up with Perl or something, but this
guy is making route caching sound like something new, when it has been in
crappy $4000 workgroup-class layer three switches now for almost a decade.
This kind of deflates his "I should know" appeals to authority.

The buffer-alternative algorithm isn't well explained but sounds kind of novel
and useful. It would be particularly so if it allows the network operator to
manage flows on a per subscriber basis.

One other concern: if this router is cutting power/weight corners by
decreasing its ability to calculate new routes ("flows"), it's possible that
an ISP would be exposing themselves to a DoS of their network by intruders
sending a lot of unique flow requests to the router. An obvious example of
this would be several concurrent NMAPs of a large range of IPs.

If it can keep up with the large workloads they claim with only 300w and 3U
(or so) of space, it's pretty compelling, all of these issues aside. I'm
excited to see it in the real world.

~~~
wmf
Here's a more technical description:
<http://packet.cc/files/Flow%20%20Management.pdf>

My take is that flow routing is not necessarily cheaper than doing full
routing on every packet, but building a router with virtually no buffers
requires tracking flows and interacting with TCP.

------
oomkiller
I see no mention of UDP in this article, which is what 99% (if not more) voice
and video traffic is transmitted as (omitting stuff wrapped in HTTP). Can it
also detect flows of UDP?

~~~
wmf
99% of audio/video is wrapped in HTTP, so if 99% of the remaining 1% is UDP,
it hardly matters. But yes, Anagran supports UDP.

------
joss82
Is computing a hash over 4x4bytes (+1 protocol bit) really faster than looking
up an address (that is only 4bytes long, btw) in an optimized routing table ?

That seems counterintuitive to me.

~~~
tptacek
Yes, because every address seen by the router isn't in some simple lookup
table in the router, unlike the flow table (or the CEF table or whatever your
hardware has).

That's not to say this is a huge win --- I don't think it is --- but yes, flow
lookups are a simpler problem than per-packet routing and per-packet
N-dimensional classification.

------
gjm11
See [http://arstechnica.com/tech-policy/news/2009/07/mind-the-
flo...](http://arstechnica.com/tech-policy/news/2009/07/mind-the-flows-and-
the-packets-will-take-care-of-themselves.ars) for some skeptical comments on
this.

~~~
tophat02
EXACTLY. It's not that radical. Sad to see ieee drinking too much Kool-Aide.

------
bendtheblock
From an aesthetic perspective, here are some router designs done recently by
Goldsmiths students in London - [http://www.creativereview.co.uk/cr-
blog/2009/july1/the-humbl...](http://www.creativereview.co.uk/cr-
blog/2009/july1/the-humble-router-re-imagned)

I like the idea of a router that shows you average signal strength throughout
the day.

~~~
bendtheblock
Apologies, I can see the link I posted has absolutely no relevance to the
context in which routers are discussed in the article.

------
modeless
A "radical" new router? Perhaps a more apropos 80s adjective would be
"tubular"?

edit: OK, HN doesn't like puns? Good to know.

~~~
scott_s
We don't like things that contribute to the noise.

