nanog mailing list archives
Re: 923 Mbps across the Ocean ...
From: Marshall Eubanks <tme () multicasttech com>
Date: Sat, 8 Mar 2003 16:26:38 -0500
e-VLBI could easily live with a 1% packet loss rate, so I see no need for it to use TCP. (Much higher and the correlator hardware
will probably start having trouble staying in sync.) The 1.8 Gbps igrid2002 demo used UDP, for example. http://www.hep.man.ac.uk/~rich/VLBI_web/igrid2002_index.html On Saturday, March 8, 2003, at 03:43 PM, Cottrell, Les wrote:
We have been talking to the radio astronomy people. We are aware they have such needs, however, I am unclear whether they have succeeded in transmitting single stream TCP application to application throughput of 900Mbits/s over 10,000km on a regular basis. Perhaps you could point me to whom to talk to. I am aware of the work of Richard Hughes-Jones of Manchester
Alan Whitney <awhitney () haystack mit edu> Hans Hinteregger <hhinteregger () haystack mit edu> Hisao Uose <uose.hisao () lab ntt co jp> Craig Walker < cwalker () nrao edu>
University and others and the Radio Astronomy VLBI Data Transmission (see for example http://www.hep.man.ac.uk/~rich/VLBI_web/) since we have shared notes and talked together a lot on the high performance issues. My understanding is that for today they use special high performance tapes to ship the data around, and are actively looking at using the network.
Today, yes, although the disk drive based Mark 5 system will be rapidly rolled out, as it will substantially reduce operating costs.
http://web.haystack.mit.edu/e-vlbi/whitney.pdf (BTW, the Mk5 deployment plan http://ivscc.gsfc.nasa.gov/program/Mk5plan_disks.pdf involves buying a metric ton of shippable disk drives.)Tape shipping for the USNO VLBI correlator is on the order of $ 50K per month (not counting recorder maintenance), so the real question is, when will it be possible to ship 1 Gbps data by fiber cheaper than than by FedEx. As the data are loss tolerant, and as buffers are cheap, thus the interest in using worse than best effort bandwidth. (If anyone is interested in the this, I am trying to have an informal bar bof to discuss it at the SF IETF.)
I cannot see how this is really relevant to NANOG and would suggest that it be taken off list.
-----Original Message----- From: alex () yuriev com [mailto:alex () yuriev com] Sent: Saturday, March 08, 2003 12:23 PM To: Jason Slagle Cc: Richard A Steenbergen; fingers; nanog () merit edu Subject: Re: 923 Mbps across the Ocean ...On Sat, 8 Mar 2003, Richard A Steenbergen wrote:A) The amount of arrogance it takes to declare a land speed "record" whenthere are people out there doing way more than this on a regular basis.Single stream at 900mbs over that distance? Where?Talk to folks that deal with radio telescopes. Alex
Regards Marshall Eubanks T.M. Eubanks Multicast Technologies, Inc. Phone : 703-293-9601 Fax : 703-293-9609 e-mail : tme () multicasttech com http://www.multicasttech.com Our New Multicast Workshop : http://www.multicasttech.com/workshop
Current thread:
- Re: 923 Mbps across the Ocean ..., (continued)
- Re: 923 Mbps across the Ocean ... Adam Kujawski (Mar 07)
- Re: 923 Mbps across the Ocean ... Scott Weeks (Mar 07)
- Re: 923 Mbps across the Ocean ... Miles Fidelman (Mar 07)
- Re: 923 Mbps across the Ocean ... Scott Weeks (Mar 07)
- Re: 923 Mbps across the Ocean ... Majdi S. Abbas (Mar 07)
- Re: 923 Mbps across the Ocean ... Andrew Dorsett (Mar 07)
- Re: 923 Mbps across the Ocean ... E.B. Dreger (Mar 07)
- Re: 923 Mbps across the Ocean ... Hank Nussbacher (Mar 08)
- Re: 923 Mbps across the Ocean ... Jessica Yu (Mar 08)
- Re: 923 Mbps across the Ocean ... Andrew Dorsett (Mar 07)
- Re: 923 Mbps across the Ocean ... Peter Salus (Mar 07)
- RE: 923 Mbps across the Ocean ... Cottrell, Les (Mar 08)
- Re: 923 Mbps across the Ocean ... Marshall Eubanks (Mar 08)
- RE: 923 Mbps across the Ocean ... Pete Templin (Mar 10)
- Re: 923 Mbps across the Ocean ... Marshall Eubanks (Mar 10)
- Re: 923 Mbps across the Ocean ... Adam Kujawski (Mar 07)