923Mbits/s across the ocean

Joe St Sauver JOE at OREGON.UOREGON.EDU
Sat Mar 8 23:14:49 UTC 2003


Hi,

#High speed at reasonable costs are the end-goal. However, it is important 
#to be able to plan for when one will need such links, to know what one 
#will be able to achieve, and for regular users to be ready to use them 
#when the commonly available. This takes some effort up front to achieve 
#and demonstrate.

And that's the key point that I think folks have been missing so far about
all this. Internet2 provides excellent connectivity to folks who generally
have a minimum of switched 10Mbps ethernet connectivity, and routinely switched
100Mbps connectivity. However, if you look at the weekly Abilene netflow 
summary reports (see http://netflow.internet2.edu/ , or jump directly to a 
particular report such as http://netflow.internet2.edu/weekly/20030224/ ) 
you will see that for bulk TCP flows, the median throughput is still only
2.3Mbps. 95th%-ile is only ~9Mbps. That's really not all that great,
throughput wise, IMHO.

Add one further element to that: user expectations. Users hear, "Wow, 
we now have an OC12 to Abilene [or gigabit ethernet, or an OC48, or an 
OC192], I'll going to be able to *smoke* my fast ethernet connection ftping 
files from <insert far away place>!" ... but then they find out that no, in 
fact, if they are seeing 100Mbps for bulk TCP transfers, then they are in 
true throughput elite,  the upper 1/10th of 1% of all I2 traffic.

SO! The I2 Land Speed Record is not necessarily about making everyone
be able to do gigabit-class traffic across the pond, it is about making
LOTS of faculty be able to do 100Mbps at least across the US.

Emprirically, it is clear to me that this "trivial" accomplishment, e.g.,
getting 100Mbps across the wide area, is actually quite hard, and it is only 
by folks pushing really hard (as Cotrell and his colleagues have) that the 
more mundane throughput targets (say, 100Mbps) will routinely be accomplished.

Regards,

Joe St Sauver (joe at oregon.uoregon.edu)
University of Oregon Computing Center



More information about the NANOG mailing list