low cost wifi monitoring probes - cesnet€¦ · low cost wifi monitoring probes arne Øslebø...
TRANSCRIPT
9/14/15 SLIDE 2
WiFi problems
● Statements from UNINETT customers– “we need improved tools for
wireless monitoring”
– “current tools not good enough”
– “how to troubleshoot”
– “continuous QoS measurements are interesting”
– “Ad-hoc and permanent probes”
– “monitoring in auditoriums”
– “specialized tools: Fluke, MetaGeek
xkcd.com
Approach and vision
● Simulate end user clients– Not great antennas
– Support wide range of 802.11 standards
● Low cost– Many probes rather than a few “awesome” ones
● Flexible and open source– Simple and flexible solutions
– No big developments
● Focus on what to measure and not how– Find interesting metrics
– Streamlined control and management of probes not important
UNINETT WiFi monitoring probe
9/14/15 SLIDE 4
NTNU, Gløshaugen, Auditorium F1
System overview
ProbeProbeProbe APMeasurement Logging
Performance Services
Config Manager
Measurement & Alarm Presentation/Delivery
Probe Registration
Raspberry PI
Measurement location
IT departement
UNINETT
HW PlatformMinimum Platform
Raspberry PI Mod B+ PSU, 8GB mini-SD, basic enclosure D-Link Wireless AC DWA-171 Dual Band (2.4GHz, 5Ghz) 802.11b, 802.11a, 802.11g, 802.11n, 802.11ac (draft 2.0) HW ver. A1
OptionalNano-size USB flash drive AUD310-16G-RBKEnhanced enclosure ModMyPi Model RB-BLKPoE power feed unit TP-Link TL-POE10R
9/14/15 SLIDE 6
Raspberry PI B+ Starter Kit
DWA-171
WiFi
Nano-USB Flash drive Enhanced enclosure
~80 EUR
Full packet ~110 EUR (before volume discounts)
HW alternatives
SW Platform
Operating System options provided by raspberrypi.org
Raspbian - Debian WheezyPidora - Fedora Remix, OpenELEC - An XBMC Media Centre, RaspBMC - An XBMC Media Centre, RISC OS - A non-Linux distribution, Arch Linux - A lightweight Linux distributionKali linux
9/14/15 SLIDE 8
Additional/Upgraded Packages / SW required or used in prototypeRaspbian kernel 3.12.28+WPA supplicant 2.2 (wpa_supplicant, wpl_cli, iwlist)Realtek 802.11ac (rtl8812au) Linux driver v4.2.2 compiled for 3.12.28+ Zabbix-agent, iperf3, curl“Coding”: pure bash, awk, bc (nothing fancy)
Measurement loop
scan
connect
http
owamp
bwctl
rtt report
check update
disconnect
sleep 5 min
Configuration ManagerEach probe contacts the config server regularily and check if there are new config files available for download.Directory structure on config server seperates probes belonging to each domain by a dedicated group, under which all their probes are given a directory (named by the mac) for storage of config files etc. An archive of all previous used configs for a probe is also kept, in a sub-directory named previous
9/14/15 SLIDE 10
rpiconfgroup
macbash scriptstimerconf.ver.currentconf.ver.new
previous
10-09-14-150811.tar10-09-14-153018.tar10-14-14-124933.tar10-14-14-141454.tar
Measurement Parameters
Layer 3Response time (DNS, HTTP)TCP throughput Up/DownBoth IPv4 and IPv6 used in L3 testing
Layer 2Association time (i.e. time to authenticate and associate with spesific ssid)Connect time (i.e. time to get IP address)
Layer 1SSID announcements (ssid seen, eduroam, per freq band, …)Frequency information (advertised, connected)Signal strength/quality
9/14/15 SLIDE 11
Some results
Possible future metrics
Packet loss (e.g. RUDE/CRUDE active probing)Measurements per frequency bandSeparate monitoring for each 802.11 standardApplication level probing, e.g. SIP Sample based monitoring (i.e. connect/measure/disconnect/sleep X minutes) vs. Continuous monitoringMisc. authentication mechanisms….
9/14/15 SLIDE 13
Future work
● Better management of probes– Ansible
● Better logging of errors● Evaluate Raspberry Pi 3● Web page for downloading
images– Available soon
● Web page for controlling probes– Continuous monitoring or
disconnect
– Disable throughput tests
GEANT WiFiMon
● Crowdsourced WiFi monitoring● Javascript on commonly visited
web page● Get performance data from clients● RADIUS server logs identifies AP● Hybrid solution
– Combine crowdsourced data with hardware probes
https://lists.geant.org/sympa/info/wifimon-users