Quality of Service in Data Networks

Quality of Service in Data Networks

QoS [email protected] http://tenet.knu.ac.kr/ 2020 2 14 [email protected] 1 QoS SLA QoS QoS QoS DiffServ Bandwidth Broker QoS Internet2 : Qbone TEN-155 : TF-TANT

2020 2 14 You Z. Cho 2 Internet data as the dominant traffic type Internet booming Future applications Dramatic growth in IP traffic Double every 6 months Service integration over IP IP telephony Settop box High speed data 2020 2 14 You Z. Cho

3 Self similarity 2020 2 14 You Z. Cho 4 1998 MCI 44(TCP ACK, TCP control segment, telnet), 552/576(TCP MSS), 1500(Ethernet MTU)byte 60% 40-44byte 75 552byte 40-44byte byte 7% "the nature of the beast: recent traffic measurements from an Internet

backbone" (Inet, '98) 2020 2 14 You Z. Cho 5 (cont.) Byte volume Packet volume flow volume TCP : byte 95%, packet 90%, flow 80% UDP : byte 5%, packet 10%, flow 18% ICMP : 2020 2 14 You Z. Cho 6

(cont.) Byte volume Packet volume flow volume WEB : byte 75%, packet 70%, flow 75% DNS : flow 18% 1% byte 3% packet 3% SMTP : byte 5%, packet 5%, flow 2% FTP : byte 5%, packet 3%, flow 1% NNTP : byte 2%, packet 1% , flow 1% 2020 2 14 You Z. Cho 7 QoS WWW = World Wide Wait : 15 : 280~590ms

: 5~20% / 2020 2 14 You Z. Cho 8 QoS? ITU-T Rec. E.800 The collective effect of service performance which determined the degree of satisfaction of a user of the service QoS : Packet end-to-end delay Delay jitter Packet loss ratio 2020 2 14 You Z. Cho

9 SLA(Service Level Agreement) ? I agree that my offered traffic will stay within this specific profile 2020 2 14 I agree that we will provide specified throughput, delay, jitter, packet loss to your InProfile traffic for this monthly charge You Z. Cho 10 SLAs and SLSs SLA Legal/Financial Other Tech.

2020 2 14 SLS Legal and financial specifications (not interesting here) Service Level Specification (technical) Traffic conditioning specification Other technical specifications (e.g. reliability/availability, service metrics, etc.) TCS You Z. Cho 11 Customer SLA SLA

Domain 1 Customer SLA Domain 2 SLA SLA Customer Customer Domain : Region of shared trust, administration, provisioning 2020 2 14 You Z. Cho 12 ISP SLA

AT&T, MCI WorldCom, Sprint, UUNET ISP IIJ(Internet Initiative Japan) 1999 6 1999 1 ISP 2020 2 14 You Z. Cho 13 ( ) ISP AT&T MCI WorldCo m Sprint

99.9% 10 80ms 1% 100%

85ms 15 100% 99.9% 1 3 (100% )

85ms 10% 100% ( ) 2020 2 14 You Z. Cho 14 QoS QoS QoS QoS QoS

QoS QoS QoS 2020 2 14 You Z. Cho 15 Admission control Classification e.g. MF (Multi field) or BA(Behavior Aggregate) Conditioning metering, marking, shaping, dropping e.g. leaky bucket, token bucket, TSW(time sliding window) Queue management RED, RIO, etc

Queue scheduling Priority queueing, WFQ, WRR, CBQ, etc 2020 2 14 You Z. Cho 16 QoS QoS Integrated Service/RSVP Differentiated Service MPLS QoS Application Layer IntServ/RSVP Transport Layer DiffServ Constraint Based Routing

MPLS Network Layer Link Layer 2020 2 14 You Z. Cho 17 IntServ/RSVP Host Application Process RSVP Process RSVP Process Policy Control

Admission Control Traffic Classifier 2020 2 14 Router Routing Process Policy Control Admission Control Packet Scheduler Traffic Classifier You Z. Cho

Packet Scheduler 18 DiffServ 2020 2 14 You Z. Cho 19 Bandwidth Broker Bandwidth Broker (BB) A type of policy server Repository of policed database, includes authentication Manage the QoS resource based on the SLA Users request bandwidth from BB BB sends authorizations leaf/border routers Resource allocation in ISP Domain Static SLA boundary router can be manually configured

Dynamic SLA signaling process e.g. RSVP, COPS, SIBBS etc. 2020 2 14 You Z. Cho 20 Bandwidth Broker(cont.) Bandwidth Brokers : admissions control manage network resources configure leaf and edge devices Source Destination SLA Domain 2 Domain 1 Core

routers Leaf Router : police, mark 2020 2 14 Core routers Egress Router Ingress Router : shape aggregates classify, police, mark aggregates You Z. Cho 21 BB Conceptual Model Adjacent BB Adjacent BB Major Blocks Inter Domain

Application Server user/host network operator User/App Iface Data Store edge router(s) 2020 2 14 Simple Policy Service Intra Domain PM iface NMS iface

Routing info Intra-domain protocol Inter-domain protocol User interface Network Management Interface Routing interface Policy functions Local resource and configuration data edge router(s) You Z. Cho 22 Examples of End-to-End

Service Delivery Delivery of AS with a Static SLA CN1-BB 2 1 3 Sender LR1 CN1 2020 2 14 7 5 4 ER1 6

8 Core Router BR1 ISP1 You Z. Cho BR2 9 ER2 CN2 Receiver 23 Examples of End-to-End Service Delivery(cont.) Delivery process of Premium Service with a dynamic SLA 2

3 CN1-BB 7 1 8,9 10 LR1 Sender CN1 2020 2 14 4 7 11 6 12 ER1

13 BR1 ISP1-BB CN2-BB 6 14 Core Router ISP1 You Z. Cho 5 15 BR2 16 ER2

CN2 Receiver 24 QoS SLA ? IEPM WG QoS , QoS 2020 2 14 You Z. Cho

25 QoS QoS QoS eg. RSVP Diagnostics , SNMP + QoS MIB => QoS eg. RTFM WG NetTrafMon 2020 2 14 You Z. Cho 26 QoS (cont.) QoS , QoS

QoS QoS 2020 2 14 You Z. Cho 27 QoS : , box : ( : ) ( : SNMP) 2020 2 14 You Z. Cho

28 two way delay, loss 1 : ping, echoping, fping, Nikhefping, gnuplotping : PingER( ping ) one way delay, loss Surveyor, RIPE-NCC project, SMARTbit, etc route traceroute, visualroute, etc throughput

netperf, iperf, BING, etc monitoring tcpdump, snoop, netxray, ewatch, WebTrafMon, etc SNMP based MRTG 2020 2 14 You Z. Cho 29 QoS Internet2 DiffServ Qbone Qbone BB QPS(Qbone Premium Service) TEN-155 TF-TANT

TF-TANT DiffServ QoS Monitoring Policy server 2020 2 14 You Z. Cho 30 TF-TANT 2020 2 14 You Z. Cho 31 TF-TANT : fully specified not yet fully specified Differentiated Services RSVP to ATM SVC

Mapping QoS Monitoring MPLS IP over ATM Flow-based Monitoring Analysis IP Version 6 ATM Signalling 2020 2 14 Multicasting (IP and ATM) Policy Control (IP and ATM) Route Monitoring VPNs WDM SDH Concatenation Issues (STM-1 vs STM4c) You Z. Cho 32 DiffServ & QoS Measurement

Participants CERN, CSELT, DANTE, University of Utrecht, etc Group 1 The support of the Expedited Forwarding (EF) Weighted Fair Queuing (WFQ) & Priority Queuing (PQ) one-way delay, jitter, packet loss percentage & burst size Group2 AF in DiffServ WRED (Weighted Random Early Detection) per-class aggregate throughput 2020 2 14 You Z. Cho 33 Aggregation Experiments Delay Delay for 1 stream from aggregate Yellow baseline (1 EF stream)

Blue 4 EF streams (aggregation only) Red 4 EF streams + 1 BE stream bottleneck 2020 2 14 You Z. Cho Measurement Based Analysis of EF PHB Forwarding, IWQoS2000 34 Aggregation ExperimentsJitter Jitter: Varying EF load and number of flows EF load varies from 200 Kbps 1200 Kbps Can be caused by packet clumping from PQ 2020 2 14

You Z. Cho 35 TF-TANT Work accomplished(2000. 6) Network configuration Baseline performance testing Configuration of GPS capable QoS measurement equipment Definition of QoS measurement test plan Future activities study of TCP related issues: ACK coloring, TCP and UDP aggregations with AF Interoperability testing (other future platforms: NORTEL, TELEBIT, TORRENT, Linux) Diffserv and MPLS Diffserv and IntServ Policy management and BB 2020 2 14 You Z. Cho 36

MPLS MPLS fast re-route MPLS VPNs Plan MPLS-TE, Diff-Serv & MPLS Interoperability between software from several vendors MPLS over a non ATM network Flow based monitoring analysis Mechanisms Cisco NetFlow Cabletrons LFAP IETFs RTFM 2020 2 14 You Z. Cho 37 Qbone 2020 2 14 You Z. Cho 38

Qbone IETF Diff (EF PHB) + QBone Serv (QPS) QBone Premium Service Idea: converge on Jacobsons VLL Premium service Well-defined SLS: Plus important value-adds: Integrated measurement/dissemination infrastructure Experimentation with pre-standards inter-domain bandwidth brokering and signaling 2020 2 14 You Z. Cho 39 QBone MIB based Statistics Active Measurement Intra Domain AM Node

Premium Path Boundary Router PM Node PM Node Passive Measurement 2020 2 14 Intra Domain Premium Path Passive Measurement You Z. Cho 40 QBone (cont.) Collection metrics, EF and BE... Active metrics

One-way delay-variation One-way loss Traceroutes e.g. IPPM Surveyors Passive metrics Load Discards (suggested) Link bandwidths (suggested) EF reservation load e.g. OCxMon, RTFM, MIBs 2020 2 14 You Z. Cho

41 QBone (cont.) Dissemination HTTP, even for raw data real-time + archived measurements Canonical names for: Metrics, Domains Standard URL name space for: MRTG-style plots Raw ASCII data http://// / //..{html | gif | txt} 2020 2 14 You Z. Cho 42 Phased Introduction of BB Functions in QBone

Phase 0 (1999.4) BB prototype Have only a human "bandwidth broker". Phase 1 ( ) BB prototype Statically defined SLSs with bandwidth broker messages exchanged Phase 2 ( ) Later prototypes with possibly "improved" interdomain BB protocol and additional functions Dynamic SLS negotiation, most AAA functions and policy functions 2020 2 14 You Z. Cho 43 BB End systems (or agents) to bandwidth brokers Web interface, RSVP, DIAMETER, COPS Bandwidth brokers to routers CLI, SNMP, COPS, LDAP

Inter-domain Communication SIBBS(Simple Inter-domain Bandwidth Broker Signalling) TCP Simple request-response protocol 2020 2 14 You Z. Cho 44 Qbone BB BB Globus, MCI/WorldCom, Merit, UCLA, etc.. Intra communication Intra domain communication Merit DIAMETER

No authentication, authorization topology OSPF FreeBSD/ATLQ UCLA COPS static configure FreeBSD/ALTQ BCIT(British Columbia Institute of Technology) BBTP(BB Transport Protocol) CA*Net II static SLA No Policy 2020 2 14

You Z. Cho 45 Bandwidth broker SLA , , QoS , SLA SLA Static or dynamic? QoS ? QoS , , SLA BB QoS 2020 2 14

You Z. Cho 46 (cont.) QoS QoS DiffServ-MPLS-IntServ domain Per domain QoS? QoS ? QoS Traffic engineering Constraint-Based Routing routing policy? 2020 2 14 You Z. Cho

47 IntServ & RSVP IntServ ATM IntServ DiffServ DiffServ Fairness Marker, Meter, Packet discarding QoS QoS ATM 2020 2 14 You Z. Cho 48

IP (2000) (2000) Real-Time Application LAN (1999) B-ISDN ETRI(1998) ATM (1997) ATM ABR ETRI(1997) B-ISDN (1997) 2020 2 14 You Z. Cho 49

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