Ingemar,
This particular response may be best for the ICCRG list and its
research view of things, but would it be possible to accomplish some
of what you want to do directly or indirectly through PlanetLab? I
don't recall the connectivity requirements and layout for PlanetLab,
but to avoid ECN info lost from encapsulated traffic between PlanetLab
sites, perhaps one could find multi-homed hosts that can also be
reached via the Internet. And since the hosts are targeted for
research work, one should be able to add some of the test software you
are speaking of below. (but this is just an educated guess on my part)
-ken
On Aug 20, 2009, at 7:43 AM, Ingemar Johansson S wrote:
Hi
Sorry for the cross-post, I would believe that it is best to reply
to tsv-area only.
I have previously asked people regarding the support of ECN
especially for UDP flows.. There seems to be a lot of uncertanities
around this and in general it is difficult to get any clear view (if
there is any ?)
So... how do I best test this on a larger scale ?
1) UDP port 7: The idea is to ping other host with UDP packets on
port 7, some of the packets are ECT(0)/(1) marked, some are not. If
I get things right, port 7 is not genarally enabled these days, are
there any host around that are known to leave port 7 open.
2) Modified STUN client: The idea is to do STUN requests to a number
of STUN servers. Some of the STUN requests are ECT.
3) Setup a mesh of volountary hosts that installs a software that
agrees to communicate via a specific port, the hack would need to
implement some means to communicate NAT'ed addresses etc. This would
require some logistic effort to gather up volounteers for the test-
fest.
Ideally the test should be able to tell if possible ECN issues are
located close to the user (e.g firewalls, WLAN routers etc) or in
the core-networks. Also I believe that running UDP would be
beneficial even though I know some people have already tried with
ICMP.
Which would be the best alternative in order to do such a test ?,
comments/suggestions are welcome.
Regards
Ingemar
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Ingemar Johansson
Senior Research Engineer, IETF "nethead"
EAB/TVK - Multimedia Technologies
Ericsson Research Ericsson AB
Box 920 S-971 28 Luleå, Sweden
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