Measurements on Layer 2 and OpenFlow Paths

Prasad Calyam, Ph.D. (PI)

Arunprasath Selvadhurai, Sudarshan Rajagopalan, Saravanan Mohan

Progress Update @ GEC14, July 2012

Infrastructure Measurement Slices in GENI

• Conducting I&M related experiments on: (i) Monitoring GENI backbone and access networks carrying non-IP traffic(ii) Monitoring of OpenFlow networks (“plastic slices”)

• Using “OSU VMLab – Utah Emulab” VLAN as a testbed for experiments– End-to-end Path: OSU – OARnet – Internet2/NLR Meso-scale Backbone – Utah– Virtual Desktop Cloud (VDC) experiment slice was setup along with a parallel

I&M slice using perfSONAR tools and OnTimeMeasure– Experiment slice was setup before GEC13 and has been active for

experimentation; I&M slice functional since April

• Use Cases– Run active measurements to check connectivity and performance as part of

Layer 2/OpenFlow slice monitoring– Schedule experiment and active measurement traffic in a conflict-free manner,

and use measurement intelligence for adaptation (e.g., load balancing)

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Experiment Slice Setup Details• Multi-domain federation involved in slice setup

– OARnet domain (VLAN 1750) from OSU VMLab connected to Washington OpenFlow-enabled switch – verified connectivity using MAC address tables

VLAN MAC ADDRESS TYPE INTERFACE 1750    000e.0c67.836e    DYNAMIC     Gi1/0/14 (from VMLab Data Center) 1750    0012.e222.6fe6     DYNAMIC     Gi1/0/26 (from Washington Switch)– NLR and Internet2 domains providing Layer 2 connectivity (VLAN 3716) through

the OpenFlow backbone network across GENI

• OpenFlow connectivity between the OSU VMLab, and Utah data centers with the thin-clients (WAPG nodes) is enabled by making them part of TangoGENI’s OpenFlow VLAN 3716 in the IP subnet 10.42.116.x

• NOX network controller was setup at pc32.emulab.net at Utah Emulab

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OSU VMLab – Utah Emulab Testbed

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Parallel I&M Slice Topology

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I&M Slice Setup Details• Evaluated setup of LAMP (custom linux image for GENI) for GENI nodes

and perfSONAR-ps (Knoppix bootable CD image) for VMLab node

• LAMP not supported on all node types in GENI – PG machine setup failed; in such cases we installed BWCTL and OWAMP tools separately

“*** Node mapping precheck failed!*** Node mapping precheck failed!

*** ERROR: mapper: Unretriable error. Giving up.seed = 1336171786…………………………“Type precheck passed.  *** No possible mapping for pg51       OS 'GeniSlices/UBUNTU91-LAMP' (OS-2283) does not run on this hardware type!*** Node mapping precheck failed!”

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Test Scenarios

1. Run ‘IP Ping’ and ‘Layer 2 Ping’ to check connectivity– Investigate utility of Layer 2 tools (Layer 2 Ping or pingPlus, ARPing)

compared to traditional IP Ping tool2. Run VDC application on ‘OpenFlow network’ path and compare

performance with ‘Internet’ path– Investigate improved performance of video stream playback and GUI

application control due to Layer 2 paths3. Run VDC application and measurement tools in ‘concurrent’ and

‘exclusive’ modes and compare performance– Motivate need for meta-scheduler in perfSONAR to integrate with

experiment applications4. Run VDC application ‘with’ and ‘without’ load balancing enabled

with OpenFlow controller and compare performance– Motivate need for ‘routing engine’ and ‘service delivery’ capabilities of

OpenFlow for Future Internet applications7

Test Scenario-2 Paths Evaluated

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Internet Path

OpenFlow Network Path

Test Scenario-2 Application Measurements

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GUI Applications consume more bandwidth and take higher task time in Internet path

Video Applications consume more bandwidth and provide higher video quality in OpenFlow path

Test Scenario-3 BWCTL Measurements

• Ran VDC application and BWCTL TCP tool in ‘concurrent’ and ‘exclusive’ modes and compared performance (pg51 node results below)

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Application measurement resumed

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 1001051101151201251301351400

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Intervals (min)

Nor

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0 - BWCTL measurement, without

Application in schedule

Both BWCTL and Applicationmeasurements scheduled concurrently

Application measurement temporarily suspended

Conclusion• Lessons learnt

– I&M needs to be a parallel slice for the experiment– Multi-domain Layer 2 connectivity testing is challenging and

troubleshooting requires collaboration– Impact of I&M can be seen on the experiment if measurement

conflict scheduling occurs– Sample OpenFlow slice RSpecs from GPO are helpful

• Next steps to improve GENI I&M frameworks– Need to integrate ‘Meta-scheduler’ to orchestrate active

measurements and multi-experiment traffic– Need to have easier methods for experimenters to:

• Integrate application metrics (e.g., VDC experiment application)• Provide OpenFlow slice traffic visibility (e.g., topology visualization,

interface configuration, interface/flow statistics)

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Thank you for your attention!