DiffServ DiffServ QoS DiffServ DiffServ host host host host Internet

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1 InternetWeek2000 Diffserv Diffserv QoS IP IP DS ISP

2 DiffServ DiffServ QoS DiffServ DiffServ host host host host Internet

3 IP: TCP: QoS 90 QoS IP IP IP

4 QoS QoS packet scheduler input driver internet forwarding output driver

5 QoS (admission control) (classifier) (shaping)(policing) (packet scheduler) (signaling)

6 ( ) ( ) IP src_addr, dst_addr, src_port, dst_port, proto Diffserv TOS

7 Priority Queueing WFQ (Weighted Fair Queueing) CBQ (Class-Based Queueing) Drop-Tail/Drop-Head/Drop-Random RED (Random Early Detection) Priority Queueing priority queues packet classifier priority scheduler

8 WFQ (Weighted Fair Queueing) per-flow queues packet classifier packet scheduler WFQ: service assigned rate packet(i) length backlogged packet length backlog start time vt(i-1) virtual time vt(i) time

9 Link 100% agency X 70% agency Y 30% ftp 40% telnet 30% ftp 20% telnet 10% class 0 class 1 class 3 class 4 pri: 2 pri: 3 pri: 2 pri: 3 CBQ (Class-Based Queueing) (set overlimit) packet default class estimator classifier class 1 packet scheduler (weighted-round robin) class 2

10 RED (Random Early Detection) TCP ECN (Explicit Congestion Notification) RED Penalty-box RED 1.0 Packet Drop Probability mark prob 0 0 min thresh max thresh Average Queue Size

11 ARPA o u

12 Queueing Delay 0 0 Load 1.0 Parekh

13 Parekh s Model WFQ sender WFQ WFQ WFQ receiver token backet Parekh + + D i b i g i (h - 1) l i g i i h m=1 l max r m D i b i g i h i l i r m delay bound for flow i token bucket size for flow i weighted rate for flow i hop count for flow i max packet length for flow i bandwidth at hop m

14 QoS ISDN ATM (Broadband ISDN) IntServ DiffServ ATM VC CBR, UBR, VBR,...

15 ATM ATM ATM TE( ) QoS

16 IntServ/RSVP QoS 89 IETF 94 IntServ IntServ QoS RSVP (ReSerVation Protocol) IntServ IntServ IntServ Guaranteed QoS control QoS Controlled-Load LAN App WAN TCP

17 [ r, b, p, m, M ] r: rate Token Buffer b: bucket size Data Packet Data Buffer p: peak rate m: min policed unit M: max packet size RSVP IntServ

18 RSVP DiffServ ISP IntServ/RSVP ISP TOS

19 DiffServ QoS (CoS: Class of Service) TOS QoS (CoS: Class of Service) QoS: QoS: QoS QoS

20 QoS QoS QoS QoS QoS DiffServ QoS

21 TOS IPv4 4-bit version 4bit header length 8-bit time to live (TTL) 8-bit type of service (TOS) 16-bit identification 8-bit protocol 3-bit flags 16-bit total length (in bytes) 13-bit fragment offset 16-bit header checksum 32-bit source IP address 32-bit source IP address options (if any) data TOS (1) IP precedence (3bits) 0-7 TOS (4bits) precedence low delay throughput reliability min cost

22 TOS (2) precedence: telnet: Diffserv TOS ISP SLA (Service Level Agreement) SLS (Service Level Specification) ISP

23 Diffserv IETF 1997/08 Munich IETF Int-serv WG Diff-serv BOF Premium Service Model Drop precedence Model Cisco s CoS 1998/03 IETF Diff-serv WG ISP Premium Service Model EF PHB V. Jacobson (LBL) 10 ATM CBR

24 Drop precedence Model AF PHB D. Clark (MIT) RIO (RED with IN and OUT) RED RIO RIO (RED with In and Out) IN/OUT IN OUT RED OUT 1.0 Packet Drop Probability mark prob OUT IN 0 0 OUTmin OUTmax INmin Average Queue Size INmax

25 Cisco s CoS Class Selector PHB F. Baker (Cisco) Cisco IP Precedence WRED (Weighted RED): 7 RIO IETF DiffServ DS (RFC1394 ) IPv4 TOS IPv6 Traffic Class PHB SLA (Serviece Level Agreement)

26 DiffServ (1) static DiffServ (2) forwarding behavior BA DiffServ

27 DSCP (behavior aggregate) DSCP PHB ISP A ISP B C SLA E B B SLA C SLA E B C: customer E: edge node B: border node DS DS DS DSCP DS DSCP DS PHB

28 DS DS DSCP PHB DSCP DS

29 DS TOS 6 DSCP (DiffServ Code Point) DS 64 DS DSCP DiffServe CodePoint TOSDS 2 ECN IPv6 Traffic Class precedence low delay throughput reliability min cost DS Field (differentiated services field) (currently unused)

30 PHB (Per-Hop Behavior) DSCP PHB DSCP PHB 64 DSCP PHB Default PHB DSCP in packet PHB 1 PHB 2 64 entry lookup table

31 Diffserv PHB ingress interface traffic conditioner egress interface PHB shaper classifier meter dropper marker forwarding classifier queues dropper marker scheduler (marker, dropper) marker to Queue A input traffic classifier meter discard dropper marker to Queue B meter marker example traffic conditioner

32 BA(Behavior Aggregate) DS MF(Multi-Field) DS token-bucket r, b in-profile: out-of-profile:

33 color-aware/color-blind profile: r:rate, b:depth output: in-profile or out-of-profile packet input < (r, b) in-profile out-of-profile tokenbucket meter

34 2-rate 3-color meter/marker peak profile: r:rate, b:depth committed profile: R:rate, B:depth output: green, yellow or red < (R, B) green packet input < (r, b) yellow red peak rate tokenbucket committed rate tokenbucket 2-rate 3-color meter/marker DS DSCP

35 PHB (Per-Hop Behavior) PHB PHB AF Drop precedecnce PHB AF Class PHB

36 PHB Default PHB Class Selector PHB EF PHB AF PHB xxxxx0: Standard PHBs xxxx11: Experimental/Local Use xxxx01: Experimental/Local Use* : Default PHB xxx000: Class Selector PHBs cccdd0: Assured Forwarding PHBs ( ) ccc: class {1,2,3,4} dd: drop prec {1,2,3} : Expedited Forwarding PHB

37 Default PHB DSCP = Class Selector PHB IP Precedence Precedence WFQ, WRR, CBQ

38 EF (Expedited Forwarding) PHB PHB Conditioning PQ WFQ, WRR, CBQ AF (Assured Forwarding) PHB Precedence TCP UDP Precedence

39 PDB (Per-Domain Behavior) DS PHB PDB DS PDB Virtual Wire PDB EF PHB PDB Virtual Wire PDB core router edge router leaf site virtual wire diffserv network

40 EF AF EF (1) connection: from <src> to <dst> profile: <r>:rate, :tokenbucket depth in-profile: delay: less than <msec> packet loss: less than <%> out-of-profile: discard classifier: <src><dst> to customer s TC TC (traffic conditioner): tokenbucket meter: <r>, in-profile: mark <EF DSCP> out-of-profile: drop

41 EF (2) Provisioning DS EF <src> to <dst> EF AF (1) connection: from <src> committed profile: <R>:rate, :tokenbucket depth peak profile: <r>:rate, :tokenbucket depth in-committed-profile: packet loss less than <%> in-peak-profile: packet loss less than <%> out-of-profile: best effort classifier: <src> to customer s TC TC (traffic conditioner): trtcm: <R>,,<r>, green: mark <AF11 DSCP> yellow: mark <AF12 DSCP> red: mark <AF13 DSCP>

42 AF (2) Provisioning DS AF1 green PEP PDP (COPS, PIB) PDP: Policy Decision Point PEP: Policy Enforcement Point PEP PEP PEP PDP COPS protocol PEP

43 COPS (Common Open Policy Service) RSVP / Request/Decision (COPS-PR) TCP ( ) PIB (Policy Information Base) RSVP PIB, diffserv PIB Integrity object or IPSec COPS-PR COPS-PR (COPS Usage for Policy Provisioning) PEP COPS Configuration Request (PEP to PDP) / Decision (PDP to PEP) Policy PDP PDP unsolicited decision (install/update/delete) PEP unsolicited request

44 DiffServ DS Bandwidth Broker RSVP over DiffServ DiffServ over MPLS DS PHB

45 Bandwidth Broker DS PDP PEP PEP PDP PEP PDP PEP COPS protocol PEP PDP: Policy Decision Point PEP: Policy Enforcement Point DiffServ

46 Provisioning RSVP over DiffServ DiffServ RSVP RSVP RSVP Edge RSVP Edge EF path

47 ISP DiffServ DiffServ < > IETF: IETF diffserv WG: IETF issll WG: IETF rap WG: ALTQ: < > Internet Performance Survival Guide. G. Huston. Wiley. ISBN Differentiated Services for the Internet. K. Kilkki. ISBN Quality of Service. P. Ferguson and G. Huston. Wiley, ISBN An Engineering Approach to Computer Networking. S. Keshav. Addison-Wesley, ISBN High-speed Networks: TCP/IP and ATM Design Principles. W. Stallings. Prentice Hall, ISBN Gigabit Networking. C. Partridge. Addison-Wesley, ISBN

IP: TCP: QoS 90 QoS IP IP IP

InternetWeek99 QoS DiffServ kjc@csl.sony.co.jp DiffServ DiffServ DiffServ DiffServ IP: TCP: QoS 90 QoS IP IP IP QoS QoS (admission control) (classifier) (shaping)(policing) (packet scheduler) (signaling)