Just how big a load are UDP broadcasts?

eddy at isi.edu eddy at isi.edu
Wed Jul 31 23:22:52 UTC 1996

> I run a small network of small sites, including a couple in the
> Adirondacks with 56k feeds.  When a user of one of these sites uses
> one of the UDP audio or video services it drives the 56k to 100%
> saturation (load 255/255) and makes the site unusable for everyone
> else.
> Recently I "solved" this problem by blocking this traffic at the entry
> port for my T1 feed.  To my surprise, both the average and peak
> traffic on the T1 dropped by a factor of 3, although less than 2% of
> my users complained.
> Traffic on my T1 wasn't the issue, but this has me wondering: how much
> of the Internet congestion my users do complain about is due to UDP
> audio/video services?
> In my very limited view of the world, UDP is a very poor network
> citizen among protocols.  Am I wrong in that view?

no not really. udp unlike tcp has no form of inherent rate control
and must rely on the application, unlike tcp which performs rate
control (congestion control).

for sake of discussion we can roughly equate net citizen ship with 
how fairly it uses the network, in otherwords it's cc.  this being 
the case udp is not really a citizen, (since it has no cc) like tcp 
is, rather the bad citizen is the application or the user. :)

> --
> Dick St.Peters,       Gatekeeper, Pearly Gateway, Ballston Spa, NY
> stpeters at NetHeaven.com     Owner, NetHeaven 518-885-1295/800-910-6671
> Internet for Albany/Saratoga, Glens Falls, North Creek, & Lake Placid
> 	  First Internet service based in the 518 area code


- rusty
eddy at isi.edu

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