presentation to spirent 18/09/2002

18/09/2002 Presentation to Spirent 1

Presentation to Spirent18/09/2002


Agenda

Presentation: Scope and Reasons.

Active “Grid Networking” Projects

Tests & Measurements


Scope

What do we do?MISSION: “Demonstrate e2e managed bandwidth services in a multi-

domain environment, in the context of Grid project requirements.”

What does it involve ? Managed bandwidth and Quality-of-Service provision

High performance, high bandwidth data transfers

Demonstrate end-to-end network services

Network Resources Reservation

An end-to-end Technology Trial (MPLS, DiffServ, Inter-domains, …)


Why ? (case for Physics Particles)


Why ? (distributed data in the Grid framework)

Online System

~100-400 MBytes/sec

~PByte/sec

CERN 700k SI95 ~1 PB Disk; Tape RobotTier 0 +1

Tier 1 ~2.5 GbpsFNAL: 200k SI95; 600 TBIN2P3 Center INFN Center RAL Center

Tier2 Center2.5 Gbps

Tier2 CenterTier2 CenterTier2 CenterTier2 Center Tier 2

Institute ~0.25TIPS

Workstations0.1–1 GbpsPhysics data

cache

~2.5 GbpsTier 3

Tier 4

Giga- (G) 109

Tera- (T) 1012 = 1000GPeta- (P) 1015 = 1000000G


Grid Project

DataGRID

SitesIn

Europe


Grid Sites in UK

Cambridge

Newcastle

Edinburgh

Oxford

Glasgow

Manchester

Cardiff

SouthamptonLondon

Belfast

DL

RAL Hinxton

“Production Network”

managed by UKERNA

(1Gb – 10Gb)


Active “Grid Networking” Projects

MB-NG (http://www.mb-ng.net)

Currently it is the main project in the network research community in UK.

High Throughput, e2e QoS in UK over “Development Network” (managed

by UKERNA).

Funded by UK research councils (PPARC, EPSRC,…).

DataTAG (http://datatag.web.cern.ch)

Large-scale intercontinental testbed for data-intensive Grids

High Throughput, e2e QoS between Geneva and Chicago

Funded by the European Commission – EU Grant IST-2001-32459 .

http://www.mb-ng.net/





http://datatag.web.cern.ch/







“Development Network”

Gigabit Ethernet2.5 Gbit POS Access2.5 Gbit POS coreMPLS Admin. Domains

Dark Fiber (SSE)POS

WorldCom

LeedsSJ4 DevC-PoP

Warrington12416

SJ4 DevC-PoP

London12416

UCLOSM-4GE-WAN-GBIC

UCLOSM-4GE-WAN-GBIC

MCCOSM-4GE-WAN-GBIC

MANOSM-4GE-WAN-GBIC

RALOSM-4GE-WAN-GBICRAL

OSM-4GE-WAN-GBIC

OC48

SJ4 DevULCC12016

OC48

WorldComSJ4 DevC-PoP

Reading12416

OC48ULCC

OC48OC48

OC48

MB - NG

UKERNA Also for other projects like IPv6.


MB-NG Partners

Partners:SPIRENT,CISCO,ACTERNA,UKERNA,CLRC-RAL, CLRC-DARESBURY, Manchester, UCL+ plus Lancaster and Southampton+ Jon Crowcroft (Cambridge)


DataTAG Project

EU Transatlantic Grid project

EU Partners:CERN/PPARC/INFN/UvA/INRIA

US Partners: Caltech, ESnet, Abilene, PPDG, iVDGL…

The main focus are:– Grid Network Research including:

• Provisioning (CERN)• Investigations of high performance data transport (PPARC) • End-to-end inter-domain QoS + BW • Network resource reservation• Bulk data transfer and monitoring (UvA)

– Interoperability between Grids in Europe and the US • PPDG, GriPhyN, DTF, iVDGL (USA)PPDG, GriPhyN, DTF, iVDGL (USA)


DataTAG Layout

Abilene

ESNET

UKSuperJANET4

ITGARR-B

GEANT

NLSURFnet

2.5 Gbit PoS lambda

SLAC

Cisco

Juniper

Alcatel

Cisco

Juniper

AlcatelGigaSwitch

JuniperLight

SwitchGigaSwitch

Cisco6509

JuniperLight

Switch

CERN (Geneva)Starlight (Chicago)

Fermi


Spirent

How Spirent can help us? Generation of “realistic internet” Traffic.

Traffic needs to be “DiffServ” marked. (Three Classes: EF, LBE, BE).

Gigabit / OC48 POS interfaces capability.

Reliable and Highly accurate timing measurements.

Capable of generating traffic on schedule.


Measurements

Generic Metrics. One Way Delay / Latency

Throughput

Jitter

Packet Loss

Consecutive Packet Loss


Traffic Scenarios

Traffic Distributions. “Constant Bit Rate” (CBR)

“Exponential Distributions” (EXP)

“Heavy Tail Distributions” (HT)

QoS Traffic. DiffServ Enabled.

Classes

Strict Priority (EF)

AF ?

Less Best Effort (LBE)

Best Effort (BE)


Specific TestsLatency vs. Packet Size

Throughput vs. Packet Size

For both: UDP and TCP.

For all Traffic Scenarios: CBR, EXP and HT.

For each Class: EF, LBE, BE


AccuracyCritical for “One Way Delay” & Jitter

Bounding the error in measurement.

GPS needed (Src/Dst), specially for long trunks:

London – Manchester (MB-NG)

Geneva – Chicago (DataTAG)

Man Lon

sGbpsBytes 23.05.2

8*72

Worst Case Scenario: 72 Bytes Frame


Flows Dependency

For TCP only, “Checking dependency on the number of Flows”.

Repeating the Tests: Latency vs. Packet Size

Throughput vs. Packet Size


“Bursty” TrafficPacket Loss vs Burst Size. CBR Traffic Scenario.

Measuring “Packet Loss” changing the duration of the “Burst

Window” for a given traffic rate.

Repeating changing the traffic rate.

100ms 200ms

… 10s

1Mbps 0.01% 0.2% 1%2Mbps % % %… % % %100Mbps

% % %

CBR

Burst Window (T) OFF ON

T


I/O RatesSent Rate vs. Received Rate. Interesting in the “Device Calibration Stage” in the lab.

Wire Rate level (with constant packet size).

UDP/TCP

Repeat changing packet sizes.

Sent Rate

Received Rate


Long Transfer Tests

Latency vs. File Size. Controlling the File Size.

Can we do that?.

UDP/TCP


TCP Packet Re-sequencing

Detection. How can it be measured ?

Determination of Cause (why ?)

Determination of Location (where ?)

Effectiveness of Congestion Control Strategies. Drop strategies (eg, RED, TailDrop,.. ).

Policing (eg. In case of congestion decrease class priority).

ECN (eg. Interaction with RED and “rogue” end systems)


Open Questions

Spirent TCP stack implementation. Any ACK in the TCP ?.

Generation of Realistic Traffic. Packet Sizes / Distributions / Number of Flows

Spirent devices to simulate Transatlantic Delays

Measuring Consecutive Packet Loss

Playback Recorded Traffic

Load specified per class/flow, not shared load per port

Measuring effects of Traffic policing (reclassification)

FEC-UDP implementation (Forwarding Error Correction)


Thank You…

presentation to spirent 18/09/2002

Documents

grid network research

ukproduction network

network research community

distributed data

e2e qos

ivdgl usa presentation

e2e managed bandwidth

gbit pos corempls