Transcript ICFA/SCIC Monitoring WG Les Cottrell – SLAC representing the ICFA/SCIC Monitoring WG Prepared for the ICFA-SCIC, KEK, Dec 12, 2002 http://www.slac.stanford.edu/grp/scs/net/talk/icfa-dec02/icfa-dec02.ppt Partially funded by DOE/MICS.

ICFA/SCIC Monitoring WG
Les Cottrell – SLAC representing the ICFA/SCIC
Monitoring WG
Prepared for the ICFA-SCIC, KEK, Dec 12, 2002
http://www.slac.stanford.edu/grp/scs/net/talk/icfa-dec02/icfa-dec02.ppt
Partially funded by DOE/MICS Field Work Proposal on Internet End-to-end
Performance Monitoring (IEPM), also supported by IUPAP
Administrivia
• ICFA-SCIC-MON web page
http://www.slac.stanford.edu/xorg/icfa/scic-netmon/ &
• Email list [email protected]
• Report: http://www.slac.stanford/xorg/icfa/
• Membership:
Person
From
Represents
Les Cottrell
SLAC
US/Babar/ESnet
Richard H-Jones
Manchester
UK/JAnet
Sergei Berezhnev
MSU, RUHEP
Russia/FSU
Sergio Novaes
FNAL
L. America
Fukuko Yuasa
KEK
Japan & E. Asia
Sylvain Ravot
Caltech
US/CMS
Daniel Davids
CERN
CERN, Europe, LHC
Shawn McKee
U Mich
Atlas/I2
Outline 1/2
• 12 page report
– Goal: Obtain as uniform picture as possible of the
present performance of the connectivity used by the
ICFA community
– Follow on to May 1998 report from ICFA/NTF
– Measurements & results for:
• PingER low intrusion, wide coverage, long term. Excellent
overview of performance for general worldwide Internet
usage
• IEPM-BW higher intrusion, high performance links such
as major HENP, Grid and network research sites. Aimed
at understanding achievable performance for TCP/IP and
applications
Outline 2/2
• Coverage & definitions of 11
major regions
• How to interpret impact of loss
& RTT on quality of common
applications: VOIP, video,
telnet …
• PingER
– Loss
– RTTs
– Throughput ~ MSS/(RTT*sqrt(loss))
• IEPM-bw high performance links
• Summary
• Recommendations
History – Loss & RTT
• Loss more critical than RTT
• Losses cause timeouts of
typically seconds
• 40-50% improve/yr
• Best networks below 0.1%
• Russia, SE Europe, China
several years behind
• N. America & Europe
improving 10-20% per year
• Japan & Russia slower
• S.E. Europe & China faster
History - Throughput quality
improvements from US
80% annual
TCPBW < MSS/(RTT*sqrt(loss)) (1)
improvement ~
factor 10/4yr
~Factor 100 improvement in 8
years
Problems with hi-perf links
• Most regions improving at 6080% / year
(1) Macroscopic Behavior of the TCP Congestion Avoidance Algorithm, Matthis,
Semke, Mahdavi, Ott, Computer Communication Review 27(3), July 1997
Loss by region
Bad regions: Caucasus, S. Asia (India), Africa
Poor: S.E. Europe
High performance (IEPM-BW)
• PingER NG, PingER on steroids …
– 9 monitoring sites,
– 50 monitored hosts in 9 countries (CA, CH, CZ, FR, IT, JP,
NL, UK, US).
– Off the shelf hdw, OS, TCP stack, MTUs, NICS
• More focused on particular paths
• Can achieve hundreds of Mbits/s between major intercontinental sites
• Requires “wizard” configuration of TCP, powerful host,
GE interfaces, >= 622Mbits/s to site
• Lot of work on new TCP stacks
eJDS (Electronic Journal Distribution Service)
• Abdus Salam International Center for Theoretical Physics (ICTP) sponsored
• ICTP Workshop on "Developing Country Access to Digital Publishing",
Trieste, October, 2002, sponsored by ICTP, ICSU, IUPAP, UNESCO, TWAS
& WIF (http://www.ictp.trieste.it/ejournals/meeting2002/)
– Goal: bring together all interested parties to analyse, share experiences,
promote ideas and discuss
•
•
•
•
innovative technological tools,
the digital divide,
licensing issues,
concrete strategic alternatives
• To support scientists working in remote areas and having lowbandwidth, or expensive access to on-line database services and the
Internet.
• developed recommendations to provide guidance and make suggestions on
how to support concrete and sustainable alternatives to help bridge the
digital divide and thus facilitate, in particular, developing countries' access to
on-line scientific publishing (see www.ictp.trieste.it/ejournals/meeting2002/Recommen_Trieste.pdf)
– To devote resources to monitor in real time the connectivity of research and
educational institutions in developing countries and to encourage (and devote
resources to) the development of the connectivity.
• Sent letter to site contacts in developing countries
eJDS
• ICTP people sent letter on Dec 2, 2002 to contacts in
developing countries
– plan to monitor by PingER universities and research
institutions all over the Developing World following the
recent "Recommendations of Trieste" to help bridge the
Digital Divide.
– Next day 6 responses (MD, IN (Hyderabad, Kerala), MX, GT,
PH, IN)
– Since 6 more (CN, UA, IN (Madras, Delhi), BR, ID)
– Successfully monitoring 6 (GT, BR, MD, IN (Kerala), ID)
– Others cannot access host, blocking pings, have emailed
each one, and communicating with a couple
Summary - results
• Internet A&R connectivity performance is
improving
– RTT 10-20%/yr, loss 40-50%/yr, throughput 80%/yr
– Reduced use of satellites, mainly use for new hard
to get to areas (e.g. S. Russian Republics, Africa)
• China, S.E. Europe, Russia, Latin America rate
of change keeps up but several years behind
• Caucasus, Africa, India, S.E. Europe bad to
poor packet loss
• Improvements need constant investments to
understand & improve
Recommendations
• Continue to keep track of performance for
HENP and science
• Work with ICTP to extend to more countries,
help understand and measure the digital
divide {should we add this?}
• Heads up: DoE funding runs out at end of FY
03.
Help
• Looking for better hosts to monitor & contacts in:
–
–
–
–
–
Albania, Armenia, Austria, Azerbaijan
Macedonia*, Turkey*, Yugoslavia
Columbia*, Venezuela*, Cuba, Mexico*
Pakistan
Africa (apart from Egypt, Uganda & South Africa, n.b. all 54
countries in Africa now have Internet access in capitals)
– Note there are a few countries (about 5% of the world’s
countries) that do not have full Internet connections and pay
dearly by the byte.
• A couple of years ago these included: Afghanistan, Western Sahara,
Christmas Island, S. Georgia, Marshall Islands, Myanmar,
Montserrat, N. Korea, Pitcairn, St Vincente & Grenadines