BNL’s Network diagnostic tool

IPERF was used and combined with different strategies to analyze network bandwidth performance such as:

-Test with iperf server inside firewall (where oracle cluster resides)-Test with iperf server outside firewall.-Test with client at CERN to host inside/outside BNL firewall-Test with client inside BNL’s firewall host inside firewall-Test with client at BNL’s bounder firewall host inside firewall.

These tests can be deployed for different well known parameters IPERF tool has such:-w, TCP window size (64KB- 8MB)- t, time to transmit (default 10 seconds)-P, number of parallel clients threats.

Test IPERFSingle Stream

Client host

CERN 137.138.76.18

Host/Location

Bandwidth

iperf -c oraclus02.usatlas.bnl.gov -w 2MB -t 40 -i 5 -p 3938

Oraclus02 Inside firewall 130.199.185.13

40.0Mbits/sec

iperf -c dcdoor02.usatlas.bnl.gov -w 2MB -t 40 -i 5 -p 22000

Door Outside firewall 192.12.15.3

77.5 Mbits/sec

BNL’s simple test to show firewall impact on bandwidth using IPERF

Firewall effect, campus net

0

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0 200 400 600 800 1000 1200

Mbps (tx)

Mbps (rx)

netqos01-dcdoor03

netqos02-dcdoor03

netqos01-gridgk01

netqos02-gridgk01

netqos01-gridgk02

netqos02-gridgk02

BNL’s elaborated test using IPERF to study firewall’s impact on bandwidth

Host/Location

Inside firewall

gridgk01

gridgk02

Outside firewall

dcdoor03

netgos02

netogos01

-Single iperf stream with bandwidth throttled at the router.

-Test performed the same day same network traffic.

-Results showed how the bandwidth is constrained by the firewall.

Fig 1. By Dimitrios Katramatos

Web100 based Network Diagnostic Tool (NDT)

-Performs 2 TCP throughput tests between the host originator and the NDT server

-Data is streamed for 10 seconds from host originator, then a second 10 second test is performed in opposite direction.

-A web100 modified Linux kernel captures statistics on TCP data flows. -The Web100 software implements instruments in the Linux TCP/IP stack. -Deals with the problem of host systems that is optimized for low bandwidth environments, and the lack of effective instrumentation and tools to diagnose performance issues.

-The NDT tool can diagnose excessive packet loss due to faulty cable.

-If the buffer size from the host originator is low the tool reports to increase it.

In order to access this tool a web browser and java needs to be installed on the host originator

Other publicly accessible NDT servers:

* Argonne National Laboratory - IL (USA) * Swiss Education and Research Network (Switzerland) * Rochester Institute of Technology - Rochester NY (USA) * University of Michigan - Flint MI (USA) * University of California - Santa Cruz CA (USA)

BNL’s NDT testTest NDT

Originator Host

NDT SERVER

http://newmon.bnl.gov:7123/ 130.199.3.7

Inside BNL Firewall

gridgk01.usatlas.bnl.gov

130.199.185.6

CP/Web100 Network Diagnostic Tool v5.3.3e

click START to begin

Checking for Middleboxes . . . . . . . . . . . . . . . . . . Done

running 10s outbound test (client to server) . . . . . 496.99Mb/s

running 10s inbound test (server to client) . . . . . . 604.12Mb/s

Outside BNL Firewall

dct00.usatlas.bnl.gov

192.12.15.8

CP/Web100 Network Diagnostic Tool v5.3.3e

click START to begin

Checking for Middleboxes . . . . . . . . . . . . . . . . . . Done

running 10s outbound test (client to server) . . . . . 943.87Mb/s

running 10s inbound test (server to client) . . . . . . 846.62Mb/s