Network Troubleshooting or … Is there any hope my Performance will be seen over the network? Bob Riddle – Technologist January 2005

What is a network geek doing at a New World Symphony seminar?  Did I come to share my musical talents? I played the bassoon in elementary school & middle school I taught myself to play a guitar, I now play it 1 week a year My kids gave me a harmonica – want to hear me play?  No? then let’s look at some network stuff using the network to “stretch” the stage & the auditorium the kind of tools you need in your network “toolbox”? how to “stack the deck” in your favor

Issues to consider when stretching the stage & the auditorium Speed: do you need a freeway, city street, or a dirt road? (H.323 – HDTV) Latency: is it a “telephone” call or a “movie”? (streaming or interactive) Packet Loss: is there any “junk mail” you can throw away? Things to think about when “stretching” the stage

Issues to consider: Do you need a dirt road or a freeway?  Determine the quality of the Experience Mpeg1~= 1.5 – 3.0 mpbs H.323~=384 – 1.5 mbps kbps Mpeg2~=4 – 15 mbps DV~=30 mbps HDTV ~= 20 – 270 mbps; 1.5 gbps  Determine the type of Experience One way?(streaming, broadcast) Two way?(interactive voice, video) Many way?(more than 2 end points)  Do the Math & check your “onramp”!

Issues to consider – unicast or multicast  can’t I get away with just unicast? (Real, QT) Depends on the “ road” – 384 kbps or 30 mbps stream(s) i.e. stats from earlier Victoria Secrets webcast  More than 1 million web hits during 1 st hour  283% increase in web traffic during event Unicast delivery doesn’t cheaply scale!  think of multicast as “Broadcast TV” If you have a “tuner” and your “antenna” is pointed in the right direction, just tune in the “channel” If you’re on a Internet2 backbone, you’re ready! (well, almost ready …)  Do the math (stream * potential endpoints) If there’s only 1 endpoint, use unicast If it’s a “Victoria Secrets” type thing, use multicast

If the “math” works out – then go for a test drive Take a good look at your local “roads” 1.Run internal tests across your LAN 2.Make sure you’re testing what you plan to use! 3.Find a friend “next door” to test with 4.Learn about ping, traceroute, the Detective, ethereal, iperf, DVTS, VLC & what they can tell you about your network situation 5.Start thinking about the on-ramp, the freeway, and those other “local roads” at your endpoints and potential endpoints

Network Toolbox: Basic tools  Ping – can I get from here to there? History of Ping Web Page with Ping & other tools Spend $24.95 for pretty pictures Beware! ICMP packets are now often blocked  traceroute (tracert) – what roads do I travel Web Page with Ping & other tools Spend $24.95 for pretty pictures When things good one direction but not the other, check for asymmetrical routes (then check for full duplex trouble!)

Network Toolbox: more tools  Internet2 Detective Internet2 Detective check your on-ramp to Abilene test your multicast capability Test your “speed” (bandwidth) Check you speed from here to there using “iperf”  Another “detective” Another “detective” SurfNet – NAT, firewall tests, duplex test, IPv6 test, etc.

Network Toolbox: more tools  check out your network capability: DVTS/DVGuide: readily available streams MPEG2 example (using VLC client)VLC client –Research Channel –University of Washington DVTS example (using DVTS WinXP client)WinXP client –Research Channel –University of Pennsylvania –University of South Florida –Internet2 Test Channel

Network Toolbox: great tools  ethereal – look at the traffic on your road Powerful Multi-Platform Analysis Useful for checking TTL, determining whether it’s a network problem or an endpoint problem  iperf – bandwidth measurement tool Peer-to-peer tool for performance testingPeer-to-peer tool Supports tcp, udp, multicast traffic Supports uni-directional & bi-directional testing  Mailing lists

Stack the deck in your favor  Use an early-warning system! Wouldn’t it be nice if you could figure out if there was any hope your stuff would work without having to buy/borrow/steal another expensive device to ship to each end point? Wouldn’t it be nice if you could use a cheap PC to determine if there was any hope? Wouldn’t it be nice if you could use free (or almost free!) software to determine if there was any hope?  Think about building cakeboxes

Stack the deck using the cakebox  Criteria for the cakebox: Small, inexpensive, easy to ship device No operator, no monitor, keyboard, or mouse required Just plug in a network cable & a power cable Provide web interface for non-network geeks   What it will allow you to do: Allows representative bandwidth testing Shows you what “road” you’ll travel Allows you to exercise “broadcast” (multicast) traffic You can find out if there is any hope

Stack the deck using the cakebox  Cakebox built using freely available tools:  Packaged on Linux Platform “phone-home” to LDAP server Secure access via SSL to web server Secure access via SSH directly to cakebox

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