Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)1 Diffserv testing in the wide area TF-TANT task force Tiziana Ferrari Italian National Institute for Nuclear Physics

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)2 European research network model according to diffserv (marking) DS domain Non DS capable domain MPLS NRN TEN-155 Marking policing scheduling shaping NRN diffserv domain  National Research Network (NRN) diffserv region  NRNs  diffserv core domain

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)3 Diffserv test network (Nov `99) EPFL CSELT Uni. Bologna GRNET (GR) Uni Utrecht (NL) Uni Twente (NL) EPFL (CH) SWITCH (CH) RedIRIS (SP) DANTE (Frankfurt PoP) Uni Stuttgart (DE) CSELT (IT) INFN/GARR (IT) Uni Bologna (IT) CERN (CH) Cabletron Ethernet sw Cisco C7200, C7500 IBM 2212, IBM 2216 Linux SmartBits 200 (Netcom)

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)4 Work accomplished (June 99-Oct 99) network configuration, baseline performance testing -1- marking -2- policing: functionality, token bucket tuning -3- scheduling: –CB-WFQ –SCFQ (Self Clocked Fair Queuing) -4- QoS measurement (ongoing): –goal: validation of EF PHB –parameters: one-way delay and one-way delay variation –LAN and WAN -5- definition, implementation and validation of test services: –point to point virtual leased line VLL –one-to-many virtual leased lines mVLL

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)5 Policing -1- two-parameter token bucket: – burst size tuning according to different policing rates -2- multi-parameter token bucket: –normal and exceed burst (TCP) -3- policing and scheduling: –token bucket size and premium queue size

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)6 Policing, two-parameter TB: optimum burst size for different traffic rates Small TCP burst tolerance: it can completely starve a TCP stream optimum token bucket size: function of the policing rate IBM 2212

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)7 Policing, multi-parameter TB: normal and exceed burst size tuning CISCO C7200 (Target rate: 1.25 Mbps) rule: exceed burst = 2 * normal independently of the platform normal burst = 0.5 sec * R

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)8 Scheduling and policing: two-parameter TB and premium buffer size Recommendation: token bucket size < premium buffer size (for low packet loss probability)

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)9 Scheduling: WFQ CB-WFQ (cisco) and SCFQ (IBM) traffic isolation between EF BA, AF BA and best-effort traffic: –combinations of TCP and UDP traffic –different aggregation degrees (variable number of TCP streams) class selectors, EF and AF bandwidth allocation: –no starvation –dynamic allocation among lightly loaded and overloaded classes

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)10 Scheduling: CB-WFQ and traffic isolation - WAN - Inconsistent results, for some sites TCP throughput < 1.25 Mbps (target rate) different ATM burst tolerances tuning of configuration at layer 2 needed shaping overall TCP performance improves with larger aggregation degrees traffic isolation on WAN connections can be an issue

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)11 Scheduling: Self Clocked Fair Queuing - LAN - IBM 2212 Policy = (traffic profile, validity period, diffserv action) Diffserv action = (type of marking, queue type, bandwidth) optimum traffic isolation (UDP) Premium: Kbps guaranteed (8% PPP link bw) Assured: Kbps (40% PPP bw)

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)12 Services Virtual leased line: –replacement of ATM permanent connections, support to managed bandwidth service –QoS support in/to NRN which are not ATM based >point to point VLL >one to manymVLL capacity allocation on congested links (e.g. US links) better-than-best-effort (qualitative definition)

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)13 Services: mVLL

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)14 Services: mVLL implementation

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)15 QoS measurement: 1-way delay and instantaneous delay variation (LAN) SmartBits txrx Goal : VLL service implementation and validation Metric: Type-P-One-way-Delay (RFC 2679), type-P-one-way-ipdv Variables: WFQ/SCFQ EF queue depth packet size EF queue “weight” traffic volume

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)16 One-way delay: average vs packet size 64 by 128 by 256 by 512 by 1024 by 1518 by 1280 by 1248 RFC

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)17 Latency in time

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)18 ipdv (*without* best-effort)

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)19 ipdv (*with* best-effort)

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)20 Future work Weighted Random Early Discard (WRED) interoperability testing (possible addition of new platforms) study of aggregation effects study of TCP related issues: ACK colouring, TCP and UDP aggregations with AF service implementation and validation diffserv and MPLS diffserv and intserv policy management and bandwidth brokerage

Tiziana Ferrari Diffserv testing in the wide area (TF-TANT task force)21 To know more Interim report: Diffserv test programme and interim test results: QoS measurement test programme: Activities of the TF-TANT task force: