ilta hand 8 qos/cosilta.personifycloud.com/webfiles/productfiles/703320/hand8.pdf · unused by ip...

Copyright © 2003, Cisco Systems, Inc. All rights reserved. Printed in USA.Presentation_ID.scr

ILTA HAND 8ILTA HAND 8

© 2011 Cisco Systems, Inc. All rights reserved.ILTA 2011

ILTA HAND 8QoS/CoS

ILTA HAND 8QoS/CoS

© 2011, Cisco Systems, Inc. www.cisco.com

Agenda

•Remember this is a 101 class.•What is it?•Do you need QoS?

•Explain QoS•Lab


•Real World Examples•Q&A

What is it?

•Quality of service is the ability to provide different priority to different applications, users, or data flows.

Classifying VoIP Signaling and Media with DSCP for QoShtt // i / /US/d /i /12 2t/12 2t2/f t / id /ft d


http://www.cisco.com/en/US/docs/ios/12_2t/12_2t2/feature/guide/ft_dscp.html

Quality of Service (QoS)http://www.cisco.com/en/US/products/ps6558/products_ios_technology_home.html


Why Enable QoS?ISN’T QOS AN OPTIONAL LUXURY TECHNOLOGY?

Quality ofSecurity

Necessity Luxury


Quality ofService

High Availability

QoS:• Enables IP Telephony

and Video

• Drives productivity by enhancing service levels to

Why Enable QoS?HA, Security, and QoS Are Interdependent Technologies

Quality ofService

Security


service-levels to mission-critical applications

• Cuts costs by bandwidth optimization

• Helps maintain network availability in the event of DoS/worm attacks

High Availability

Challenges of Packet Voice

DelayDelayDelayDelay

Sources of quality problems in Voice and Video over Data:


LossLoss DelayDelayDelayDelayDelayDelay

VariationVariation(Jitter)(Jitter)

DelayDelayVariationVariation

(Jitter)(Jitter)


Enterprise QoS

–Remote site has a 1350 Kbps CIR FR link –Bursty applications contending for bandwidth reduce

collective throughput. Customer needs better throughput–What can we do to improve things?


130 Kbps

1300 Kbps

C i s c o Q o S A r c h i t e c t u r a l F r a m e w o r k

Business Objectives

QoS forConvergence

QoS forSecurity

QoS forTiered Services

Vide

o

Voic

e

Dat

a


Architecture Standards

DiffServStandards

IntServStandards

HybridStandards


QoS DetailedQoS Detailed

© 2011, Cisco Systems, Inc. www.cisco.com


QoS Terms

•CoS - Class of Service, Layer 2 (802.1p)•ToS - Type of Service, Layer 3 (IP Precedence)•DSCP - Differentiated Services Code Point (DiffServ)•PHB - Per-Hop Behavior (packet scheduling, queuing, policing, or shaping behavior)

•EF - Expedited Forwarding


•AF - Assured Forwarding•CS - Class Selector•BE - Best Effort•Scavenger – Class with lowest configurable queuing service •CAC - Call Admission Control

77 66 55 44 33 22 11 00

Enabling QoS in the Campus Layer 3 Classification: IP Precedence, DSCP

IDID OffsetOffset TTLTTL ProtoProto FCSFCS IP SAIP SA IP DAIP DA DataDataLenLenVersionVersionLengthLength

ToSToSByteByte

DiffServ Code Point (DSCP)DiffServ Code Point (DSCP) Flow CtrlFlow Ctrl

IPv4 Packet

IP PrecedenceIP Precedence UnusedUnused Standard IPv4

DiffServ Extensions


• IPv4: Three most significant bits of ToS byte are called IP precedence—other bits unused by IP Precedence

• DiffServ: Six most significant bits of ToS byte are called DiffServ Code Point (DSCP)—Remaining two bits used for flow control

• DSCP is backward-compatible with IP precedence• DSCP values correspond to Per Hop Behavior (PHB) designations• RFC 2474 provides more information on DSCP

IP Precedence

•Number Name

• 0 routine

• 1 priority

IP Precedence marks packets into six classes (two reserved):

Handset

6500

Server

GSR


• 2 immediate

• 3 flash

• 4 flash-override

• 5 critical

• 6 internet – reserved

• 7 network – reserved

IP Precedence is used to determine the weight for QoS policy, for example for WFQ, WRED

3945

PBX

Server

2951

6500

3945

GSR


Enabling QoS in the Campus

48-55

56-63

Reserved

Reserved

-

-

6

7

6

7

CoSCoS IP Prec.IP Prec. PHBPHB DSCPDSCPL2L2 L3 ClassificationL3 Classification

ApplicationApplication

Classification Summary


10,12,14

18,20,22

26

34

46

0 Best Effort Data

Medium Priority Data

High Priority Data

Call Signaling

Video Conferencing*

Voice Bearer

AF1y

AF2y

AF31

AF41

EF

BE

1

2

3

4

5

0

1

2

3

4

5

0

CS3 24

IETF recommendationsIETF recommendations* Including audio * Including audio and videoand video

DiffServ Behaviors

•Expedited Forwarding (EF) PHB, low loss, low latency and jitter, assured bandwidth, end-end service– DSCP = 101110

•Assured Forwarding (AF) PHB, four classes– DSCP = 001dd0, 010dd0, 011dd0, or 100dd0, where dd is the drop preference


within the class

•Default PHB, best-effort behavior (ideally some minimum resources allocated)– DSCP = 000000

•Backwards compatible with precedence

How Is QoS Optimally Deployed?

1. Strategically define the business objectives to be achieved via QoS

2 A l th i l l i t f th


2. Analyze the service-level requirements of the various traffic classes to be provisioned for

3. Design and test the QoS policies prior to production-network rollout

4. Roll-out the tested QoS designs to the production-network in phases, during scheduled downtime


Data QoS Requirements Provisioning for Data

• Different applications have different traffic characteristics

• Different versions of the same application can have different traffic characteristics

• Classify data into four/five

Data


C y /data classes model:

–Mission-critical apps–Transactional/interactive apps–Bulk data apps–Best effort apps–Optional: Scavenger apps

• Smooth/bursty• Benign/greedy• Drop insensitive• Delay

insensitive• TCP retransmits

D a t a Q o S R e q u i r e m e n t s Provisioning for Data (Cont.)

• Use four/five main traffic classes:–Mission-critical apps—business-critical client-server applications–Transactional/interactive apps—foreground apps: client-server apps or interactive applications–Bulk data apps—background apps: FTP, e-mail, backups, content distribution


content distribution–Best effort apps—(default class)–Optional: Scavenger apps—peer-to-peer apps, gaming traffic

• Additional optional data classes include internetwork-control (routing) and network-management

• Most apps fall under best-effort, make sure that adequate bandwidth is provisioned for this default class

How Many Classes of Service Do I Need?

Example Strategy for Expanding the Number of Classes of Service over Time4/5 Class Model

Call Signaling

Realtime

8 Class Model

Video

Call Signaling

Voice

QoS Baseline Model

Call SignalingStreaming VideoInteractive-Video

Voice


Scavenger

Critical DataCritical Data

Best Effort

Bulk Data

Network Control

Scavenger

Network Management

Transactional Data

Best Effort

IP Routing

Mission-Critical Data

Scavenger

Bulk Data

Time

Best Effort


Classification and Marking DesignQoS Baseline Marking Recommendations

ApplicationL3 Classification

DSCPPHBIPP CoS

Video Conferencing 34AF414 4

Voice 46EF5 5

L2

Routing 48CS66 6


Transactional Data 18AF212 2

Call Signaling 24CS3*3 3

Streaming Video 32CS44 4

Network Management 16CS22 2

Bulk Data 10AF111 1

Scavenger 8CS11 1

Best Effort 000 0

Mission-Critical Data 26AF31*3 3

Campus Queuing DesignRealtime, Best Effort, and Scavenger Queuing Rules

Real-Time ≤ 33%

Best Effort≥ 25%


Critical Data

Scavenger/Bulk ≤ 5%

802.1Q/pHeader

PRIPRI VLAN IDVLAN IDCFICFI

Enabling QoS in the Campus Layer 2 Classification: 802.1p, CoS

TAGTAG4 bytes4 bytes

Three Bits Used for CoS(802.1p User Priority)

DataData FCSFCSPTPTSASADADASFDSFDPream.Pream. TypeType

Ethernet Frame

CoSCoS ApplicationApplication


• 802.1p user priority field also called Class of Service (CoS)

• Different types of traffic are assigned different CoS values

• CoS 6 and 7 are reserved for network use

1

2

3

4

5

6

7

0 Best Effort Data

Medium Priority Data

High Priority Data

Call Signaling

Video Conferencing*

Voice Bearer

Reserved

Reserved

CoSCoS ApplicationApplication

* Including Audio and Video


Enabling QoS in the Campus Scheduling in IP Phones

VoiceCoS = 5Voice

CoS = 5CoS = 5CoS = 5

IP Phone Enclosure

Phone


• Voice media traffic is marked with CoS 5/ DSCP EF (high priority)

• Data traffic from the PC is re-marked with CoS 0 (low priority) by the IP phone switch; this occurs if PC tags frames as 802.1p/Q;

Priority QPriority Q

Data Qs

DataCoS = 0

PCAccessSwitch CoS = 5

Call Admission Control (CAC)

• Why CAC?• Boat capacity = five persons• When the sixth person climbs

aboard everybody gets wet!


Branch Size Max Calls Actual BW

Small 3 240 KbpsMedium 8 640 KbpsLarge 16 1,280 Kbps

N k S i /N k S i /


Network Services/Media MonitoringNetwork Services/Media Monitoring

© 2000, Cisco Systems, Inc. www.cisco.com econ_0386_09_001.ppt


Quality of Experience Lack of Visibility


• High expenditures with troubleshooting

• Don’t know where the problem is most of the time

• Cannot replicate problems

• Inability to assess impact of video, voice and data applications on the network

• High-bandwidth upgrade costs

• Inability to verify service level agreements

• Provides a means to measure, validate, perform fault-isolation and assess the network’s ability to deliver high quality voice, video and data.

• Medianet Media Monitoring is a family of Cisco


Medianet Media Monitoring is a family of Cisco IOS features that enhances visibility in the Medianet Network:

Performance Monitor

Mediatrace

IP Service-Level Agreement (IP SLA) Video Operation (VO)

• Analyzes traffic to measure performance statistics like loss, delay, jitter, and others.


• Statistics can be accessed by NetFlow or MIB.

• Relevant for video, voice and data traffic.

• Alarms created based on exceeded thresholds.

Performance MonitorPerformance Monitor


• Discovers an IP flow’s path in the network.

• Dynamically enables monitoring.


• Collects information on a hop-by-hop basis.

• Collect Performance Monitor stats.

• Locates degradation along the flow path.

MediatraceMediatrace

• Assesses readiness of the network.

• Stresses the network path with realistic application-specific media streams.


• Enables testing the network to ensure configurations are correct for rich-media.

• Helps guide admin to verify problems were corrected.

IP SLA Video OperationIP SLA Video Operation

Using Performance Monitor, Mediatrace and IPSLA VO TogetherUsing Performance Monitor, Mediatrace and IPSLA VO Together

PROBLEM DETECTED.PROBLEM DETECTED.VERIFYING NETWORK VERIFYING NETWORK CORRECT PATHCORRECT PATHRUNNING RUNNING IPSLA VOIPSLA VO


“My last video session had quality problems!”“An issue was seen by Performance Monitor at the time. Fault was identified and fixed by our engineers.”

RESOLVED.RESOLVED.

“I’ve got another video meeting today. Can you make sure it will work well?”“Let me verify the network state using IPSLA VO.”

STATUS: STATUS: GOODGOOD

“Yes. It looks good. I also checked via Mediatrace that the correct path is being taken.”

CORRECT PATHCORRECT PATHCONFIRMEDCONFIRMED

“If you like, I can run IPSLA VO and Mediatrace periodically until your meeting starts…”

RUNNING RUNNING IPSLA VOIPSLA VOAND AND MEDIATRACEMEDIATRACE


• Media Monitoring provides a means to measure, validate, perform fault-isolation and assess the network’s ability to deliver high quality voice, video and data.

• 3 features: Performance Monitor, Mediatrace, and IP Service-Level Agreement (IP SLA) Video Operation (VO).

Summary


• Reduces operating costs by:

• Accelerating troubleshooting times

• Enabling users to make informed decisions with respect to the network based on actual performance data

• Enabling validation of network with realistic video traffic profiles

LabLab


LabLab

www.cisco.com

PacketTracer

–Open “Cisco Packet Tracer” on your desktop.–Go to “File” then “Open”–Find file “ILTA QoS 101.pkt”



Chicago Switch0

–Click on switch0 and highlight the "CLI" tab.–Hit "Enter"–Switch0>–Switch0>enable


Switch0 enable–Switch0#–Switch0#configure terminal–Enter configuration commands, one per line. End with

CNTL/Z.–Switch0(config)#–Switch0(config)#mls qos (enables quality of service

(QoS) functionality globally)

Chicago Switch0 cont.

– Switch0(config)#interface FastEthernet0/1– Switch0(config-if)#mls qos trust dscp (trust DSCP values coming into this interface)

– Switch0(config-if)#interface FastEthernet0/3– Switch0(config-if)#mls qos trust dscp– Switch0(config-if)#exit– Switch0(config)#exit

S it h0#


– Switch0#– Switch0#copy running-config startup-config (saves the configuration)– Destination filename [startup-config]? (Hit “enter“)– Building configuration...– [OK]– Switch0#– Switch0#show running-config

Chicago Switch1

–Click on switch1 and highlight the "CLI" tab.–Hit "Enter"–Switch1>–Switch1>enable


Switch1 enable–Switch1#–Switch1#configure terminal–Enter configuration commands, one per line. End with

CNTL/Z.–Switch1(config)#–Switch1(config)#mls qos


Chicago Switch1 cont. (1)

– Switch1(config)#interface FastEthernet0/1– Switch1(config-if)#mls qos trust dscp

– Switch1(config-if)interface FastEthernet0/2– Switch1(config-if)mls qos trust dscp

– Switch1(config-if)interface FastEthernet0/3S i h1( fi if) l d


– Switch1(config-if)mls qos trust dscp

– Switch1(config-if)interface FastEthernet0/4– Switch1(config-if)mls qos trust device cisco-phone (trust only a cisco phone plugged

into this port)– Switch1(config-if)#exit– Switch1(config)#exit

Chicago Switch1 cont. (2)

–Switch1#–Switch1#copy running-config startup-config–Destination filename [startup-config]? (Hit

“enter“)


–Building configuration...– [OK]–Switch1#–Switch1#show running-config

Chicago Router0

– Click on Router0 and highlight the "CLI" tab.– Hit "Enter"– Chicago>– Chicago>enable– Chicago#– Chicago#configure terminal– Enter configuration commands, one per line. End with CNTL/Z.

Chi ( fi )#


– Chicago(config)#– Chicago(config)#class-map match-all VoIP (note match-all)– Chicago(config-cmap)#match ip dscp ef (expedited forwarding)– Chicago(config-cmap)#match protocol http– Chicago(config-cmap)#exit– Chicago(config-cmap)#class-map match-any VoIP-Control– Chicago(config-cmap)#match ip dscp af31 (assured forwarding)


Chicago Router0 cont. (1)

–Chicago(config-cmap)#policy-map QoS-WAN–Chicago(config-pmap)#class VoIP–Chicago(config-pmap-c)#priority 600–Chicago(config-pmap-c)#class VoIP-Control

Chi ( fi )# b d id h 8


–Chicago(config-pmap-c)# bandwidth 8–Chicago(config-pmap-c)#class class-default–Chicago(config-pmap-c)# fair-queue–Chicago(config-pmap-c)# set ip dscp default (any

packet not matching above, set DSCP to zero)–Chicago(config-pmap-c)#exit–Chicago(config-pmap)#exit–Chicago(config)#


–Apply service policy to the WAN interface.–Chicago(config)#interface Serial0/0/0–Chicago(config-if)#service-policy output QoS-Wan–% policy map QoS-Wan not configured


% policy map QoS Wan not configured


–Service policy is case sensitive–Chicago(config-if)#service-policy output QoS-WAN– I/f Serial0/0/0 class VoIP requested bandwidth 600

(kbps), available only 375 (kbps)




–Change policy to use less bandwidth–Chicago(config-cmap)#policy-map QoS-WAN–Chicago(config-pmap)#class VoIP–Chicago(config-pmap-c)#priority 320


Chicago(config pmap c)#priority 320

–Try now to apply service policy to the WAN interface.–Chicago(config)#interface Serial0/0/0–Chicago(config-if)#service-policy output QoS-WAN–Chicago(config-if)#exit–Chicago(config)#exit

Chi #

Run packet simulation– Lower right hand corner click the "Stop Watch" tab next to "Realtime".– You will see "Simulation" replace "Realtime".

– Click on "PC 1" in lower left hand corner.– Select the "Desktop" tab– Click on "Traffic Generator"

S ll d d li k "S d"


– Scroll down and click "Send"– Click "Capture / Forward" button and watch the packet move from network device

to device.– Note the Envelope has a purple box indicating "Expedited forwarding" (EF).– As the packet passes from Chicago to New York the purple box is gone. (QoS

markings were removed.)– Lower right hand corner click on the "Realtime"tab.

Chicago Router0 “show policy-map”

– Click on Router0 and highlight the "CLI" tab.– Chicago#show policy-map interface serial 0/0/0

– Service-policy output: QoS-WAN

– Class-map: VoIP (match-all)– 0 packets, 0 bytes (Note these counters are NOT going up.)– Class-map: class-default (match-any)


p ( y)– 101 packets, 13402 bytes– 5 minute offered rate 320 bps, drop rate 0 bps– Match: any– QoS Set– dscp default– Packets marked xxxxxxx


Correct the QoS

–Click on Router0 and highlight the "CLI" tab.–Chicago#–Chicago#configure terminal–Enter configuration commands, one per line. End with


Enter configuration commands, one per line. End with CNTL/Z.

–Chicago(config)#–Chicago(config)#class-map match-all VoIP–Chicago(config-cmap)#no match protocol http–Chicago(config-cmap)#match protocol icmp

Run packet simulation again

–Click "Capture / Forward" button and watch the packet move from network device to device.

–Note the Envelope has a purple box indicating "Expedited forwarding" (EF).A th k t f Chi t N w Y k th


–As the packet passes from Chicago to New York the purple box remains. (QoS markings are preserved.)

Router0 “show policy-map” again

–Click on Router0 and highlight the "CLI" tab.–Chicago#show policy-map interface serial 0/0/0 – Serial0/0/0– Service-policy output: QoS-WAN


Service policy output: QoS WAN– Class-map: VoIP (match-all)– 156 packets, 44304 bytes (Note these counters

now going up.)

ilta hand 8 qos/cosilta.personifycloud.com/webfiles/productfiles/703320/hand8.pdf · unused by ip...

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