Active Measurement Project on KREONET & APAN Manhee Lee Supercomputing Center Korea Institute of Science & Technology Information

Objectives of this presentation  Introduction to KREONET  Network Analysis Infrastructure of KREONET  Introduction to AMP  Interesting results of AMP  Proposal to make AMP APAN

Introduction to KREONET  Korea Research Environment Open Network  one of the Korea ’ s national core networks since 1988  Providing an advanced S&T and R&D infrastructure to 300 R&D institutes and universities  KREONet2, next generation research network, NGI(Next Generation Internet) technologies through interconnection with STAR TAP  Help researchers process large capacity of data in supercomputers and provide activation of world-class collaborative application service

Role of KREONET High-Tech S&T devices (Supercomputers, CAVE,DB Servers…) High-Tech S&T applications based KREONET/KREONet2/HPCNet

Why Network Measurement?  Network Operators ’ View  Is the network reliable?  How is the network used?  When should the network be upgraded?  Network Users ’ View  How much do I use the network?  Should I invest more or not?  Does the Service Provider abide by its agreement?

Active Measurement  Method  inject measurement traffic into the network  Metrics  Round Trip Time, Packet loss, Topology  Tools  Ping, Traceroute, NIMI, Surveyor, PingER, AMP

Passive Measurement  Method  Do not inject measurement traffic but just observe traffic passively  Metrics  Link Utilization, Traffic amount, Traffic classification, Traffic pattern  Tools  Tcpdump, MRTG, Flowscan, OC3MON(CoralReef), Flowscan+

Network Analysis Infrastructure(NAI) for KREONET ATM Switch KOREN/KREONet2 Router KOREN/KREONet2 -STAR TAP KREONET Router STAR TAP FlowScan+ OC3MON AMP PingER Netflow AMP PingER Destination hosts Passive Measurement Active Measurement MRTG

AMP (Active Measurement Project)  Developed by NLANR/MOAT(SDSC)  A distributed network of over 120 active monitors  Systematically performing scheduled measurements(fping, traceroute) between each other monitor  All monitors send data to central data collector periodically located in SDSC  Raw and analysis data available by Web

What can AMP tell us?  Round trip time once a minute  Traces between monitors every 10 minute  Distribution of RTT  Packet Loss  History of changes of traces  Yearly, weekly, daily RTT graph

Deployment Map of AMP U.S

Structure of AMP Analysis machine active monitor Other target Analysis machine Cichlid 3D Web Browser active monitor

AMP Architecture System cron process fping traceroute AMPlets ping traceroute ping results traceroute results am_master am_slave ping results traceroute results apache cgi-bin trigger File read TCP connection ping results traceroute results ping results traceroute results File write File read am_slave AMPlet1 AMPlet2 AMPlet3 am_slave TCP connection File write HTTP Request Web Service AMP Server ping traceroute

How to use AMP?  First, select an interested AMP monitor  Currently, there are over 120 monitors  For example, let ’ s click on amp-arizona

 You can see brief traffic analysis from amp-arizona to all other monitors  yesterday ’ s minimum, mean, and max RTT, and packet loss rate  If you want to know specific traffic analysis, click the interested monitor  For example, let ’ s click on Harvard University How to use AMP?

 You can see yearly and weekly RTT graphs from Arizona State Univ. to Harvard Univ.  If you want to know more details about a specific day, click any date  For example, let ’ s click on 17 Dec 2001 How to use AMP?

 You can see more details of the day from Arizona to Harvard  Daily RTT : around 62ms  Hop count: 11  Jitter: around 1ms  RTT distribution: mostly 62ms  packet loss: many times, 10% How to use AMP?

 If click route, you can see all routes of the day  If there is any changes, you can see all the changes How to use AMP?

amp-korea  NLANR/MOAT(SDSC) gave a monitor to KISTI and allowed it to be joined the AMP infrastructure for international collaboration.  amp-korea is monitoring the performance from Korea to about 120 amp U.S sites via STAR TAP.  Those amp U.S sites are doing so in the same way. 

amp-korea HPC results

Routing Anomaly at

Problem Analysis in  From amp-korea to amp-ncsa  RTT anomaly detected. Why?

Problem Analysis in  First compare with other network.  From amp-korea to amp-sdsc  Nearly same results.

Problem Analysis in  Compare with other network.  From amp-korea to amp-ucsd  Totally different results  We can assume that this problem may not be KOREN/KREONet2-STAP TAP link problem but STAR TAP network problem.

Problem Analysis in  Take a look at STAR TAP network.  From amp-startap to amp-ncsa  At normal case, its RTT is about 2,3 ms  Why? Are there any routing changes?

Problem Analysis in  Take a look at its routing, but clean  Then, we can assume that the reason is not routing problem but may be congestion or router ’ s low performance

Problem Analysis in  Compare other network from STAR TAP  Then, we can know that all traffic patterns STAR TAP to vBNS, Abilene, and CA*net are same  So we can conclude that the problem of low network performance might be in STAR TAP routers or inside network.

AMP KREONET  To build an AMP infrastructure in KREONET  Last year, we set up two servers and 4 test AMP monitors at KREONET NOC  This year, we plan to install dozens of AMP monitors in KREONET network centers and major supercomputer users.  This AMP infrastructure will monitor the performance of the KREONET  URL: (under construction)  Software and Server Installing Guide :

Proposal to make AMP APAN  APAN ’ s individual networks, institutes, and universities have been doing their own measurements  But there is no APAN-wide or Asia-wide measurement infrastructure  Because of increasing collaboration within Asia, it will be very useful to actively measure network performance of APAN  AMP may be a good candidate for APAN performance measurement infrastructure

Expected benefits from AMP APAN  RTT, Packet loss, connectivity among APAN countries  Same information with U.S and other countries by peering with AMP U.S  Optional performance test for APAN  Performance testbed for future project such as End-to-end Performance Initiative in APAN

Is it difficult to join or make AMP APAN?  Absolutely NOT!!!!!!!!!!!  Making AMP APAN is very easy because it is cheap and easy to install  You just need one FreeBSD system  Please send us an any time, then we can help you install software  Easy to join, easy to collaborate, easy to get information and cheap to start!!  AMP APAN will be very useful for APAN  Why don ’ t you join us now?

Conclusions  With AMP, we can know RTT, Packet loss, traces, and throughput(optional)  AMP APAN will be very useful measurement infrastructure  Just one FreeBSD system is needed.  Small Investment, Big Benefit!!

Links and Contacts  Links  NLANR:  AMP: amp.nlanr.net  amp-korea: watt.nlanr.net//active  AMP KREONET: matthew.kreonet2.net (under construction)  Contacts  Engineer: Manhee Lee  Director: Okhwan Byeon  AMP US director: Ronn Ritke  Developer: Tony McGregor

Comments or Questions?  Thanks …