1. Tiziana Ferrari Differentiated Services Test: Report1 Differentiated Service Test REPORT TF-TANT Tiziana Ferrari ferrari@cnaf.infn.it Frankfurt, 1 Oct 1999

2. Tiziana Ferrari Differentiated Services Test: Report2 Overview Differentiated Services Architecture test activities test infrastructure interim results QoS measurement test plan Services

3. Tiziana Ferrari Differentiated Services Test: Report3 Differentiated Services Architecture

4. Tiziana Ferrari Differentiated Services Test: Report4 Differentiated services Why diffserv? –new technology –independent of layer 2 technologies –interoperability between independent national research networks (different requirements, infrastructures, policies and management) –traffic aggregation –scalability –no signalling –QoS for networks not ATM based cont.

5. Tiziana Ferrari Differentiated Services Test: Report5 Diffserv architecture: components DS field (1 byte) packet classification packet scheduling traffic conditioning: –metering –marking –policing –shaping DS field CU 067

6. Tiziana Ferrari Differentiated Services Test: Report6 Diffserv architecture: PHBs Per Hop Behaviours: description of the packet treatment into the network Standardised PHBs: –Expedited Forwarding (low delay, low delay variation, guaranteed bandwidth) –Assured Forwarding (Behaviour Aggregate, 4 classes, 3 drop priorities per class) Experimental PHBs PHB class selectors: XXX000 (backward compatibility with TOS precedence)

7. Tiziana Ferrari Differentiated Services Test: Report7 Diffserv architecture: network model DS domain Non DS capable domain MPLS NRN TEN-155 marking Marking policing scheduling shaping DS domain

8. Tiziana Ferrari Differentiated Services Test: Report8 Test activities: test plan current status future tests

9. Tiziana Ferrari Differentiated Services Test: Report9 Programme overview Diffserv architecture (precedence, DSCP) –test of QoS features in routers –parameter tuning –interoperability mixed diffserv-intserv architecture (end-to-end QoS) mixed diffserv-MPLS architecture QoS measurement Policy management

10. Tiziana Ferrari Differentiated Services Test: Report10 Work accomplished (from end of June 99) network configuration baseline performance testing CISCO: –CAR (Committed Access Rate): functionality and parameter tuning –CB-WFQ (Class Based WFQ): traffic isolation IBM: –policing of EF traffic –SCFQ (Self Clocked Fair Queuing): EF, AF and best-effort configuration of GPS capable QoS measurement equipment (SmartBits by Netcom Systems) diffserv deployment by a test application: MONARC definition of test services definition of QoS measurement test plan

11. Tiziana Ferrari Differentiated Services Test: Report11 Future activities Weighted Random Early Discard (WRED) testing completion of IBM testing study of TCP related issues: ACK colouring, TCP and UDP aggregations with AF interoperability testing (other future platforms: NORTEL, TELEBIT, TORRENT, Linux) service testing QoS performance measurement diffserv and MPLS diffserv and intserv policy management and bandwidth brokerage

12. Tiziana Ferrari Differentiated Services Test: Report12 Test infrastructure

13. Tiziana Ferrari Differentiated Services Test: Report13 Test network

14. Tiziana Ferrari Differentiated Services Test: Report14 LAN layout (example)

15. Tiziana Ferrari Differentiated Services Test: Report15 Equipment Test workstations traffic generators (3 SmartBits, Netcom System loan) ATM switches in the test sites cabletron ethernet switch DS capable routers: –C7200 or C7500 (partial CISCO loan) –IBM 2212 and IBM 2216 (2 routers in 5 sites, IBM donation)

16. Tiziana Ferrari Differentiated Services Test: Report16 Interim Results

17. Tiziana Ferrari Differentiated Services Test: Report17 CISCO: CAR Multi-field classification: OK packet marking (precedence setting): OK exceed action testing: OK policing (at a configurable rate): two parameters token bucket for TCP performance optimisation –normal burst –exceed burst --> parameter tuning

18. Tiziana Ferrari Differentiated Services Test: Report18 CAR: test of exceed actions Throughput: SWITCH: 1.20 Mbps DANTE: 0.38 Mbps

19. Tiziana Ferrari Differentiated Services Test: Report19 CAR: TCP burst tolerance Normal and exceed burst tuning with TCP traffic single and multiple TCP streams optimum values are functions of the rate R at which traffic is policed, in particular: normal burst = 0.5 sec * R exceed burst = 2 * normal burst

20. Tiziana Ferrari Differentiated Services Test: Report20 CAR: TCP burst tolerance (cont)

21. Tiziana Ferrari Differentiated Services Test: Report21 CISCO: CB-WFQ Scheduling mechanism to provide minimum bandwidth guarantees to classes class definition: precedence or MF classification --> OK bandwidth allocation: no starvation, no bandwidth consumption --> OK traffic isolation: scenarios –UDP high priority + UDP best-effort –TCP high priority + UDP best-effort –TCP high priority + TCP best-effort UDP --> OK (always) TCP: inconsistency

22. Tiziana Ferrari Differentiated Services Test: Report22 CB-WFQ: set-up

23. Tiziana Ferrari Differentiated Services Test: Report23 CB-WFQ: traffic isolation of a single TCP stream

24. Tiziana Ferrari Differentiated Services Test: Report24 CB-WFQ: traffic isolation of multiple TCP streams Multiple TCP streams get the bandwidth share as defined by CB-WFQ!

25. Tiziana Ferrari Differentiated Services Test: Report25 IBM: Self Clocked Fair Queuing Policy = (traffic profile, validity period, diffserv action) diffserv action = (type of marking, queue type, bandwidth) optimum traffic isolation (tests only with UDP) Premium: 163.8 Kbps guaranteed (8% PPP link bw) Assured: 819.2 Kbps (40% PPP bw)

26. Tiziana Ferrari Differentiated Services Test: Report26 IBM: EF policing Small TCP burst tolerance in a policer can completely starve a TCP stream. Token bucket depth is key parameter --> tuning need according to the rate at which traffic is policed

27. Tiziana Ferrari Differentiated Services Test: Report27 IBM: EF policing (cont) EF with TCP traffic, target rate = 163 Kbps

28. Tiziana Ferrari Differentiated Services Test: Report28 QoS measurement Resource allocation monitoring –for resource allocation and network dimensioning performance measurement –passive –active (invasive traffic) –for service validation –to understand the effect on end-to-end performance of buffering in one router or in a chain

29. Tiziana Ferrari Differentiated Services Test: Report29 Performance measurement parameters of interest: –one-way delay, requirements: clock synchronisation >GPS based synchronisation SmartBits (Netcom Systems) >NTP (Network Time Protocol) NTP client / server hierarchy –one-way delay variation –packet loss –throughput –RTT

30. Tiziana Ferrari Differentiated Services Test: Report30 Services: examples Virtual leased line: –point to point –one to many capacity allocation on congested links (e.g. US links) better-than-best-effort (qualitative definition) delay bound and delay variation sensitive traffic classes rate limiting of invasive traffic...

31. Tiziana Ferrari Differentiated Services Test: Report31 More information at Test programme: –http://www.cnaf.infn.it/~ferrari/tfng/diffserv.html more info and test results: –http://www.cnaf.infn.it/~ferrari/tfng/ds-test.html