7600 QoS - Sbeldona

8/14/2019 7600 QoS - Sbeldona

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1Cisco Confidential© 2004 Cisco Systems, Inc. All rights reserved.

Cisco 7600QoS Architecture

Srinath Beldona

[email protected]

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QoS Architecture

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QoS Architecture

Distributed QoS

Classic

Linecard

CEF256

Linecard

dCEF256

Linecard

dCEF720

Linecard

MSFC3

PFC3

16 Gbps Shared BusForwarding

Tables

Fabric

Arbitration

Net MGMT

NMP

Crossbar

Supervisor

1616

8 8 8

20 20

CEF720

Linecard

16

20 20

Where QoS Lives

Animated

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QoS Architecture

Application

•

Cisco 7600 distributes QoS features across the Supervisor Engine and the line cards

PFC3, Catalyst, FlexWAN, OSM

• Each line card family is designed to provide the QoS featuresapplicable to its role, e.g., WAN cards have deeper buffersand more features than LAN cards, while the simpler LANcards are less expensive

• Knowing the ingress and egress line cards will tell you what QoS features are available to you.

• Or vice versa, determine the QoS features you need, thenselect the appropriate line cards.

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QoS Architecture

Distribution of Features

• PFC3 on Sup720

Centralized forwarding for Catalyst, OSM, and FlexWAN line cards

Centralized policing and marking for Catalyst and OSM line cardsNo packet buffer or queuing capabilities

• Catalyst ports

Distributed packet buffering, queuing, scheduling

Hardware-based queues

Strict priority, WRR, DWWR, WRED

• OSM WAN ports

Distributed packet buffering, queuing, scheduling

Software-definable queues

CBWFQ, LLQ, Shaping, WRED

• FlexWAN ports

Fully distributed QoS; no dependencies on PFC3-based QoS

Policing, marking

Packet buffering, queuing, scheduling

Software-definable queues

WFQ, CBWFQ, LLQ, Shaping, WRED, etc.

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QoS Architecture

QoS Model

Frame

Frame

1 2 3

Ingress

QoS

Ingress

QoS

Ingress

QoS

Catalyst LAN Port

OSM WAN Port

FlexWAN Port

Supervisor 720

Egress

QoS

Egress

QoS

Egress

QoS

Catalyst LAN Port

OSM WAN Port

FlexWAN Port

P F C 3

I n gr e s s

Q o S

P F C 3

E gr e s s Q o S

P F C 3

F or w ar d i n g

Frame

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QoS Architecture

Example: QoS Model

Frame

Frame

1 2 3

Ingress

QoS

Ingress

QoS

Ingress

QoS

Catalyst LAN Port

OSM WAN Port

FlexWAN Port

Supervisor 720

Egress

QoS

Egress

QoS

Egress

QoS

Catalyst LAN Port

OSM WAN Port

FlexWAN Port

P F C 3

I n gr e s s

Q o S

P F C 3

E gr e s s Q o S

P F C 3

F or w ar d i n g

Frame

Animated

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QoS Architecture

Example: QoS Model

Frame

Frame

3 2 1

Egress

QoS

Egress

QoS

Egress

QoS

Catalyst LAN Port

OSM WAN Port

FlexWAN Port

Supervisor 720

Ingress

QoS

Ingress

QoS

Ingress

QoS

Catalyst LAN Port

OSM WAN Port

FlexWAN Port

P F C 3

E gr e s s Q o S

P F C 3

I n gr e s s

Q o S

P F C 3

F or w ar d i n g

Frame

Animated

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QoS Architecture

Example: QoS Model

Frame

Frame

1 2 3

Ingress

QoS

Ingress

QoS

Ingress

QoS

Catalyst LAN Port

OSM WAN Port

FlexWAN Port

Supervisor 720

Egress

QoS

Egress

QoS

Egress

QoS

Catalyst LAN Port

OSM WAN Port

FlexWAN Port

P F C 3

I n gr e s s

Q o S

P F C 3

E gr e s s Q o S

P F C 3

F or w ar d i n g

Frame

Animated

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QoS Architecture

Example: QoS Model

Frame

Frame

3 2 1

Egress

QoS

Egress

QoS

Egress

QoS

Catalyst LAN Port

OSM WAN Port

FlexWAN Port

Supervisor 720

Ingress

QoS

Ingress

QoS

Ingress

QoS

Catalyst LAN Port

OSM WAN Port

FlexWAN Port

P F C 3

E gr e s s Q o S

P F C 3

I n gr e s s

Q o S

P F C 3

F or w ar d i n g

Frame

Animated

Frame

Frame

Frame

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QoS Architecture

When Ingress is Catalyst, OSM

Queue

Queue

Ingress Port

Classify

Distributed

Packet Buffering

Queuing & Scheduling

Catalyst Line Cards

Optical Service Modules

Queue

Queue

Egress Port

Classify

Distributed

Packet Buffering


Catalyst Line Cards


FlexWAN

Police;

Mark

PFC3

Classify

Centralized

Policing & Marking

Forwarding

Sup720

Animated

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QoS Architecture

When Ingress is FlexWAN

Queue

Queue

Ingress Port

Classify

FlexWAN

Distributed

Policing & Marking

Packet Buffering Queuing & Scheduling

PFC3

Sup720

Centralized

Forwarding

Queue

Queue

Egress Port

Classify

Distributed

Packet Buffering


Catalyst Line Cards


FlexWAN

Animated

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QoS Architecture

Scaleable QoS

• PFC3 QoS

Centralized marking and policing

ASIC implementation

Up to 30 Mpps forwarding rate

No throughput/latency degradation when applying QoS

• Catalyst Line Card QoS

Distributed port QoS

ASIC implementationLine rate performance

No throughput/latency degradation when applying QoS

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QoS Architecture

Scalable QoS, continued

• Enhanced OSM QoS

Distributed port QoS

PXF implementation

Up to OC-48 forwarding rate• Enhanced FlexWAN QoS

Distributed IOS – policing, marking, port QoS

Dual processor implementation (versus one onVIP)

Up to 300K pps forwarding rate per Port Adapter

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QoS Command Sets

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QoS Command Sets

MQC vs. MLS QoS

• Modular QoS CLI (MQC)

Standard CLI across all main Cisco IOS-based platforms

PFC3-based policing & marking

OSM-based QoS

FlexWAN-based QoS

• Multilayer Switching (MLS) CLI

Hardware-specific command syntax

PFC3-based trust, markdown, maps, more

Catalyst card-based QoS

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QoS Command Sets

MQC vs. MLS CLI

x

x

Policing, Marking

Modular QoS CLI

FlexWAN-based QoS

OSM-based QoS

xCatalyst Card-based QoS

Trust, Markdown, Maps,etc.

PFC3

MLS CLI

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QoS Command Sets

Modular QoS CLI

class-map

Router(config)# class-map <match-all | match-any> class-map-name

Router(config-cmap)# match <access-group | ip precedence | ip dscp |

mpls exp |...>

policy-map

Router(config)# policy-map policy-map-name

Router(config-pmap)# class class-name

Router(config-pmap-c)# <bandwidth | police | shape | random-detect |

set | queue-limit |...>

service-policy

Router(config)# interface interface-name

Router(config-if)# service-policy <input | output> policy-map-name

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QoS Command Sets

MLS QoS CLI

mls qos

! Several different global & interface commands

Router(config)# mls qos ...

Router(config-if)# mls qos ...

Router(config-subif)# mls qos ...

rcv-queue

Router(config-if)# rcv-queue <cos-map | queue-limit | random-detect |threshold> ...

wrr-queue

Router(config-if)# wrr-queue <bandwidth | cos-map | queue-limit |random-detect | threshold> ...

priority-queue

Router(config-if)# priority-queue cos-map ...

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Class of Service

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Class of Service

Ethernet Tag

0 1 2 3

0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

48-bit Destination MAC Address

48-bit Source MAC Address

16-bit Ethertype (0x8100) 12-bit VLAN ID

3-bit

Prio

C

F

I

802.1p User Priority

3 bits wide; values 0–7

16-bit Length/Type Data (variable)

Data (variable) Pad (variable)

32-bit FCS

802.1q

Tag

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Class of Service

MPLS Label

TTLSEXP20-bit Label

0 1 2 3

0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

MPLS EXP


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Class of Service

IP Header

0 1 2 3

0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

4-bit

Version

Type of Service byte

IPP or DSCP

16-bit Indentification3-bit

Flags13-bit Fragment Offset

8-bit TTL 16-bit Header Checksum

32-bit Source IP Address

32-bit Destination IP Address

4-bit

Hdr Len

8-bit TOS 16-bit Total Length

8-bit Protocol

Options (if any)

Data

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Class of Service

IP TOS Byte

8 9 10 11 12 13 14 15

3-bit Precedence 4-bit Type of Service 0

6-bit Differentiated Services Control Point 2-bit Unused

Type of Service format

Differentiated Services format

8 9 10 11 12 13 14 15

IP Precedence


DSCP


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Class of Service

Putting It All Together

IP

Payload

MPLS

Label

Ethernet

Header

IP

Header

Ethernet

FCS

3 bit IPP

6 bit DSCP

802.1q

3 bits

EXP

3 bits

56

48

40

3224

16

8

0

DSCP

7

6

5

43

2

1

0

EXP

7

6

5

43

2

1

0

IP Prec

0xE07

0xC06

0xA05

0x8040x603

0x402

0x201

0x000

ToS802.1p

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Backup

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QoS Architecture

Port Types

• FlexWAN port

Port Adapter port

•

OSM portPXF-enabled OSM WAN port

• Catalyst port

Catalyst line card port

Non-PXF-enabled OSM LAN port

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OSM Architecture

OSM Ports: WAN vs. LANPOS, CHOC, DPT

or ATM OSMPOS, CHOC, DPT

or ATM OSM

GE WAN OSM

OSM WAN Ports

–PXF-enabled

– POS, CHOC, DPT, ATM, GE WAN

OSM LAN Ports

–Not PXF-enabled

– Same as Catalyst LAN ports

– GE LAN ports on POS, CHOC, DPT,ATM, Enhanced GE WAN OSMs

Enhanced GE WAN OSMEnhanced GE WAN OSM

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Class of Service

AF and EF Code Points

0xB8

0x98

0x90

0x88

0x78

0x70

0x68

0x580x50

0x48

0x38

0x30

0x28

0x00

DS Byte

34100010AF41

36100100AF42

38100110AF43

46101110EF

30011110AF33

28011100AF32

26011010AF31

22010110AF2320010100AF22

18010010AF21

14001110AF13

12001100AF12

10001010AF11

0000000Default

DecimalBinaryService Level

Documents

7600 QoS - Sbeldona