Cisco QoS: Design and Best Practices for Enterprise Networks

Cisco QoS: Design and Best Practices
for Enterprise Networks
Presenters:
Ken Briley
Technical Lead,
Cisco Systems, Inc.

Patrick Hubbard
Head Geek, SolarWinds Worldwide, LLC

© 2013 SOLARWINDS WORLDWIDE, LLC. ALL RIGHTS RESERVED.

A Few Notes about Today’s Session
» Today’s content will cover QoS design tips for Network Admins
 We will discuss QoS design and best practices
 And CBQoS reporting with SolarWinds NTA

» Ask questions!!!
 We have a Q&A session
 Don’t wait until the end – Use the chat box and we will do our best to cover
them all
 No attendee left behind – We will email you the answers

» Today’s Session is being recorded
 solarwinds.com
 slideshare.com
 You will get the links by email soon

Today’s Presenters
Ken Briley
Technical Lead,
Cisco Systems, Inc.
Patrick Hubbard
Head Geek,
SolarWinds
Worldwide, LLC

Today’s Session Agenda
• SolarWinds® Overview
• Ken Briley talks about ‘QoS Design and Best Practices’
• QoS Monitoring
• SolarWinds NetFlow Traffic Analyzer and QoS Reports

• Q&A

SolarWinds Overview
Provides enterprise-class network, systems, virtualization, and storage resource
management software that is powerful, easy-to-use, and affordable

 Rapidly Growing & Highly Profitable IT Management Company
» Founded in 1999 to deliver IT management software that works for you – and that delivers on our
mission of "unexpected simplicity."
» We sell to businesses of all sizes from SMB to Large Enterprise

» Over 100,000 customers in 170 countries
» More than 450 of the Fortune 500 are customers
» More than one million registered end-users have downloaded our free tools
4

QoS Design
Ken Briley

CCIE#9754

12-10-2013
© 2013 Cisco and/or its affiliates. All rights reserved.

Cisco Public

QoS Design
Agenda

• End-to-End QoS Design Strategy Review
• Campus QoS Design Considerations & Recommendations

• WAN QoS Design Considerations & Recommendations
• Summary and References


Cisco Public

QoS Design Strategy Review
Trends In Internet Usage

• By 2015…
 Global IP traffic will increase 8-fold
 The number of IP devices will be more than twice the global population
 Wireless traffic will exceed wired
 Non-PC traffic (smartphones, tablets etc.) will account for 15% of all traffic
 90% of consumer internet traffic will be video

http://www.cisco.com/en/US/solutions/collateral/ns341/ns525/ns537/ns705/ns827/white_paper_c11481360_ns827_Networking_Solutions_White_Paper.html

Cisco Public

QoS Design Strategy
Trends in Voice, Video and Data Media Applications
Data

Convergence

Media Explosion

• IP Video Conf

Video

• IP Telephony

Voice

Connectivity

Data
Apps

• App Sharing
• Web/Internet
• Messaging
• Email

Leveraging
Investment

Data
Apps

• IP Telephony
• HD Audio
• Softphone
• Other VoIP

• App Sharing
• Web/Internet
• Messaging
• Email

Co-Existence


WebEx

Web
Email
Messaging

Voice

• IP Video Conf
• Surveillance
• Video Telephony
• HD Video Conf
• VoD Streaming

TelePresence

Video

• Internet Streaming
• Internet VoIP
• YouTube
• MySpace
• Other

Ad-Hoc App

Unmanaged

Collaborative Media

Experience
Assurance

Cisco Public

RFC 4594-Based Strategic QoS Recommendations
Application

Per-Hop

Admission

Queuing &

Application

Class

Behavior

Control

Dropping

Examples

VoIP Telephony

EF

Required

Priority Queue (PQ)

Cisco IP Phones (G.711, G.729)

Broadcast Video

CS5

Required

(Optional) PQ

Cisco IP Video Surveillance / Cisco Enterprise TV

Realtime Interactive

CS4

Required

(Optional) PQ

Cisco TelePresence

Multimedia Conferencing

AF4

Required

BW Queue + DSCP WRED

Cisco Unified Personal Communicator, WebEx

Multimedia Streaming

AF3

Recommended


Cisco Digital Media System (VoDs)

Network Control

CS6

BW Queue

EIGRP, OSPF, BGP, HSRP, IKE

Call-Signaling

CS3

BW Queue

SCCP, SIP, H.323

Ops / Admin / Mgmt (OAM)

CS2

BW Queue

SNMP, SSH, Syslog

Transactional Data

AF2


ERP Apps, CRM Apps, Database Apps

Bulk Data

AF1


E-mail, FTP, Backup Apps, Content Distribution

Best Effort

DF

Default Queue + RED

Default Class

Scavenger

CS1

Min BW Queue (Deferential)

YouTube, iTunes, BitTorent, Xbox Live


Cisco Public

EE820906—Figure 9-6: Expanded QoS Model Based on RFC 2597-Clarification & RFC 5865
Application Class

PHB Marking

Admission Control

PHB Queuing & Dropping

Application Examples

VoIP Telephony

EF

Required

Priority Queue (PQ)

Cisco IP Phones

VoIP - Admitted

DSCP 44

Required

Priority Queue (PQ)

Admitted Voice

Broadcast Video

CS5

Required

(Optional) PQ

Cisco IPVS / Enterprise TV

BV-Admitted

DSCP 41

Required

(Optional) PQ

Admitted Broadcast Video


CS4

Required

(Optional) PQ

Cisco TelePresence

RI-Admitted

DSCP 33

Required

(Optional) PQ

Admitted TelePresence

AF41

TANDBERG EX / MXP

DSCP 35
MM-Conferencing

Admitted MM-Conferencing
Required


AF42
AF43

Cisco WebEx

AF3
MM-Streaming

Jabber / TANDBERG Movi

Cisco Cast

AF32

Recommended


AF33

Cisco Show-and-Share
Cisco Digital Signs

Network Control

CS6

BW Queue

EIGRP, OSPF, BGP, IKE

Call-Signaling

CS3

BW Queue

SCCP, SIP, H.323

OAM

CS2

BW Queue

SNMP, SSH, Syslog

AF21
Transactional Data

Order Processing Apps

AF22


CRM / ERP Apps

AF23
AF11
Bulk Data

Messaging Apps
Email

AF12


AF13

FTP
Backups

Best Effort

DF

Default Queue + RED

Default Class

Scavenger

CS1

Min BW Queue

YouTube, iTunes, BitTorent


Cisco Public

Business Requirements Will Evolve and Expand over Time
5-Class Model

8-Class Model
Voice

12-Class Model
EF

Voice

Voice

Signaling

Transactional Data

Network Control

Broadcast Video

CS5

AF4

EF

CS3

CS4

Multimedia Conferencing AF4

Interactive Video

Control

EF


AF3

CS3

Signaling

CS3
CS6

CS6

Network Control
Network Management
Transactional Data

AF2

Transactional Data AF2

CS2

AF2

Bulk Data

AF1

Bulk Data

AF1

Best Effort

DF

Best Effort

DF

Best Effort

DF

Scavenger

CS1

Scavenger

CS1

Scavenger

CS1

Time

Cisco Public

QoS Design Strategy At-A-Glance

http://www.cisco.com/en/US/docs/solutions/Enterprise/Video/qosmrn.pdf

Cisco Public

Campus QoS Design Considerations &
Recommendations


Cisco Public

Campus QoS Design—Simplified
Agenda




Cisco Public

Campus QoS Design Considerations
The Case for Campus QoS

• The primary role of QoS in campus networks is not to control latency or
jitter (as it is in the WAN/VPN), but to manage packet loss.
• In GE/10GE campus networks, it takes only a few milliseconds of
congestion to cause instantaneous buffer overruns resulting in packet
drops.
• Applications—particularly HD video applications—are extremely sensitive
to packet drops, to the point where even 1 packet dropped in 10,000 is
discernable by the end-user.


Cisco Public

Implications of Video Compression on Packet Loss Tolerance
1920 lines of Vertical Resolution (Widescreen Aspect Ratio is 16:9)

1080 x 1920 lines =

1080 lines of Horizontal
Resolution

2,073,600 pixels per frame
x 3 colors per pixel

x 1 Byte (8 bits) per color
x 30 frames per second
= 1,492,992,000 bps
or 1.5 Gbps Uncompressed

Cisco H.264-based HD Codecs transmit 3-5 Mbps per 1080p image
which represents over 99.67% compression (300:1)
Therefore packet loss is proportionally magnified in overall video quality
Users can notice a single packet lost in 10,000—Making HD Video
One Hundred Times More Sensitive to Packet Loss than VoIP!

Cisco Public

Campus QoS Design Overview
VoIP vs. HD Video—At the Packet Level
Voice Packets
1400

1400

1000

Video Packets

1000

Video
Frame

Bytes
600

Audio
Samples

600

200

200

20 msec

Time

33 msec
Cisco Public

Video
Frame

Video
Frame

How Long Can Queue-Buffers Accommodate Line-Rate Bursts?
Gbps Linecard Example (WS-X6148A-GE-TX)
140

Gbps Line Rate

Gbps Line Rate: 1 Gbps = 125 MB/s
or 125 KB/ms

100

80

Total Per-Port Buffer: 5.4 MB

60

40

Total Per-Queue Buffer*: 1.35 MB

20

0
10
30
50
70
90
110
130
150
170
190
210
230
250
270
290
310
330
350
370
390
410
430
450
470
490
510
530
550
570
590
610
630
650
670
690
710
730
750
770
790
810
830
850
870
890
910
930
950
970
990

Bytes Per ms

120

Total Per-Queue Buffering Capacity: 10.8 ms

ms

*Assuming (4) equal-sized queues

Cisco Public

How Long Can Queue-Buffers Accommodate Line-Rate Bursts?
10 Gbps Linecard Example (WS=X6716-10GE)
1400

10 Gbps Line Rate

Gbps Line Rate: 10 Gbps = 1.25 GB/s
or 1.25 MB/ms

1000

800

Total Per-Port Buffer: 90 MB

600

400

Total Per-Queue Buffer*: 11.25 MB

200

0
10
30
50
70
90
110
130
150
170
190
210
230
250
270
290
310
330
350
370
390
410
430
450
470
490
510
530
550
570
590
610
630
650
670
690
710
730
750
770
790
810
830
850
870
890
910
930
950
970
990

Bytes Per ms

1200

Total Per-Queue Buffering Capacity: 9.0 ms

ms

*Assuming (8) equal-sized queues

Cisco Public

Strategic QoS Design Principles

• Always perform QoS in hardware rather than software when a choice
exists
• Classify and mark applications as close to their sources as technically and
administratively feasible
• Police unwanted traffic flows as close to their sources as possible
• Enable queuing policies at every node where the potential for congestion
exists


Cisco Public

Campus QoS Tools and Options

• Global Default QoS Setting
• Trust States and Conditional Trust
• Per-Port QoS, Per-VLAN QoS, Per-Port/Per-VLAN QoS

• Ingress QoS Models
• Egress QoS Models
• EtherChannel QoS
• QoS Roles in a Campus


Cisco Public

Trust States and Operations
CoS = 5
DSCP = 46

CoS = 5
DSCP = 46

Untrusted
no [mls] qos trust

Trust CoS
[mls] qos trust
cos

CoS = 0

Internal
DSCP = 0

DSCP = 0

CoS-to-DSCP Mapping Table
CoS 0  0
CoS 4  32
CoS 1  8
CoS 5  40
CoS 2  16
CoS 6  48
CoS 3  24
CoS 7  56
mls qos map cos-dscp 0 8 16 24 32 40 48 56
CoS = 5

Internal
DSCP = 40

CoS = 5
DSCP = 46

Trust DSCP
[mls] qos trust dscp

DSCP = 40

CoS = 5

Internal
DSCP = 46


DSCP = 46

Cisco Public

Conditional Trust Operation
Cisco TelePresence Example
Trust Boundary
Successful “Condition” Met (i.e. CDP negotiation successful)
Trust is Dynamically Extended to Cisco 7975G IP Phone

2

1

Cisco 7975G: Voice  CoS 5 & DSCP EF
Call-Signaling  CoS 3 & DSCP CS3

3
TelePresence Primary Codec: Voice + Video  CoS 4 & DSCP CS4
Call-Signaling  CoS 3 & DSCP CS3

4
CoS-to-DSCP Map:
CoS 5  DSCP EF (46)
CoS 4  DSCP CS4 (32)
CoS 3  DSCP CS3 (24)


Cisco Public

Trust Boundary

Trust Boundaries

Access-Edge Switches

Conditionally Trusted Endpoints
Example: IP Phone + PC
mls qos trust device cisco-phone

Unsecure Endpoint
no mls qos trust


Trust Boundary

Secure Endpoint
Example: Software-protected PC
With centrally-administered QoS markings
mls qos trust dscp

Cisco Public

Per-Port QoS vs. Per-VLAN QoS
Per-Port QoS

Per-VLAN QoS
Policy map is applied to the logical
VLAN interface

VLAN Interfaces
VLAN 10
VLAN 20

VLAN Interfaces
VLAN 10
VLAN 20

Physical Ports

Physical Ports
Policy map is applied to the physical
switch port


Cisco Public

Per-Port/Per-VLAN QoS
VLAN Interfaces
DVLAN 10
VVLAN 110

DVLAN policy map is applied
to the Data VLAN (only)
on a given trunked switch port

Trunked Physical Ports
VVLAN policy map is applied
to the Voice VLAN (only)
on a given trunked switch port


Cisco Public

Campus QoS Design Recommendations Ingress QoS Models
No Trust (Untrusted)
Trust CoS
Trust DSCP

Marking Policies
VoIP Classifier
Signaling Classifier

Multimedia Conferencing Classifier

Signaling Classifier
Transactional Data Classifier
Bulk Data Classifier
Scavenger Classifier
Best Effort (Class-Default)

(Optional) Policing Policies
Mark EF

VVLAN

Signaling Policer (<32 kbps)

Mark AF41
Mark CS3
Mark AF21
Mark AF11
Mark CS1
Mark DF

DVLAN

Yes
No

MM-Conf Policer (<5 Mbps)

Mark CS3

VoIP Policer (<128 kbps)

Yes
No

Yes
No

Signaling Policer (<32 kbps)

Yes
No

Trans-Data Policer (<10 Mbps)

Yes
No

Bulk Data Policer (<10 Mbps)

Yes
No

Scavenger Policer (<10 Mbps)

Yes
No

Best Effort Policer (<10 Mbps)

Yes
No


Cisco Public

Drop
Drop

Drop
Drop
Remark to CS1
Remark to CS1
Drop
Remark to CS1

Ingress Queuing Policies
(if required and supported)

Trust Device / Conditional Trust

Campus QoS Design Recommendations
Queuing and Dropping Recommendations
• Catalyst Queuing is done in hardware and varies by platform/linecard and is
expressed as: 1PxQyT
Example: 1P3Q8T means:

1 PQ
3 non-priority queues, each with

Best Effort
≥ 25%

8 drop-thresholds per queue

• Minimum queuing capabilities is 1P3QyT

Scavenger/Bulk
≤ 5%

• Realtime (PQ) should be less than 33% of link

Guaranteed BW

• Best-Effort Queue should be guaranteed at 25% of link

• Scavenger/Bulk queue should be minimally provisioned
• Enable congestion-avoidance on non-priority queues (WRED, WTD, DBL)


Realtime
≤ 33%

Cisco Public

QoS Design—Simplified
Agenda


• Cisco Catalyst 2960/3560/3750 QoS Design
• Cisco Catalyst 4500 QoS Design
• Cisco Catalyst 6500 QoS Design

• Appendix: AutoQoS


Cisco Public

Branch Router Port Roles

Queuing/Dropping/Shaping/
Link-Efficiency Policies for
Branch-to-Campus Traffic

Classification and Marking (+ NBAR2)
Policies for Branch-to-Campus Traffic
Branch Router

Branch
Switch

WAN/VPN

WAN Edge

LAN Edge

Optional: DSCP-to-CoS Mapping Policies
for Campus-to-Branch Traffic (to Support
Legacy Branch Switches that Read Only CoS)


Cisco Public

30

WAN/VPN Router and Switch Interface QoS Roles
WAN/VPN Services Block
WAN
Aggregation
Routers

Private WAN
MPLS VPN

Metro Ethernet
IPSec VPN

Switch Port to Switch Port or Router Interface:

WAN/VPN Edge Router Interface:

• Trust-DSCP

• No Trust (IOS default)

• 1P3QyT or 1P7QyT Queuing

• LLQ/CBWFQ policies
• Additional VPN-specific QoS policies (as required)

Router Interface to Switch Port :
• No Trust (IOS Default)
• (Optional) LLQ/CBWFQ policies (only if potential for
congestion exists in WAN-to-LAN direction)

Cisco Public

Cisco MPLS VPN Design
Campus VPN
Block
E
E

Branch 1

F

F

E

MPLS VPN
F

F

E
Branch 2

CE Routers

PE Routers

CE Routers

Enterprise Subscriber (Unmanaged CE Routers)

E
≤ 33%
of BW

Outbound Policies:

Inbound Policies:

HQoS Shaper (if required)
+ LLQ for VoIP (EF), BV (CS5), RTI (CS4)
+ Remark (if necessary)
+ CBWFQ for All Other Traffic Classes
+ Remark (if necessary)

Service Provider:
Outbound Policies:

F

(Trust DSCP)
+ Restore Markings (if necessary)

+ Restore Markings (if necessary)

Inbound Policies:

+ LLQ for Real-Time Classes
+ CBWFQ for All Other Traffic Classes

(Trust DSCP)
Police on a per-Class Basis


Cisco Public

Cisco WAN QoS Design
QoS Design Steps—Cisco ISRG2/ASR1k

1. Verify SP Policy (MPLS transport only)
2. Configure Egress Queuing


Cisco Public

Four-Class SP Model Enterprise Mapping Example
Application

DSCP

Network Control

CS6

VoIP Telephony

EF

Broadcast Video

CS5  CS2

EF
CS5


AF4  AF2

CS6


CS4  CS5


AF3  AF2

AF3

Call Signaling

CS3

Transactional Data

AF2  AF3

AF2

OAM

CS2

CS2

Bulk Data

AF1

Scavenger

CS1

Best Effort

DF

4-Class SP Model

CS3

DF
Cisco Public

SP-Real-Time
(RTP/UDP)
30%
SP-Critical 1
(TCP)
20%
SP-Critical 2
(UDP)
20%
SP-Best Effort
30%

Four-Class SP-Model Bandwidth Allocation Example*
Voice 10%

Best Effort 25%

SP-Best
Effort 30%

20%

SP-Realtime
30%

TelePresence Class Supports:
2x CTS-3000 call at 1080p-Best over a
155 Mbps OC3 link

Scavenger 1%
Bulk Data 4%

SP- Critical 2 SP- Critical 1
20%
20%

OAM 5%
Multimedia Streaming 5%

Network Control 5%
Call-Signaling 5%

Multimedia Conferencing 5%
Transactional Data 10%
Broadcast Video 5%
*Traffic Allocations based on a 155 Mbps / OC3 Line Rate

Cisco Public

Cisco TelePresence MPLS VPN Design
Six-Class SP-Model Enterprise Mapping Example
Application

DSCP

6-Class SP Model

Network Control

CS6

VoIP Telephony

EF

Broadcast Video

CS5  CS2


AF4  AF2


CS4


AF3  AF2

Call Signaling

CS3

CS6
AF3
CS3

Transactional Data

AF2  AF3

AF2

Network Management

CS2

Bulk Data

AF1

Scavenger

CS1

CS2
AF1
CS1

SP-Realtime
(RTP/UDP)
10%
SP-Critical 1
(Realtime Int)
20%
SP-Critical 2
(TCP)
20%
SP-Critical 3
(UDP)
20%

Best Effort

DF

EF
CS5
CS6
CS4

DF
Cisco Public

SP-Scavenger
5%
SP-Best Effort
25%

Six-Class SP-Model Bandwidth Allocation Example*
Voice 10%

Best Effort 25%
SP- Realtime
10%

20%

SP-Best
Effort 30%
SP- Critical 1
20%

Scavenger 1%
Bulk Data 4%

SP- Critical 3 SP- Critical 2
20%
20%

OAM 5%

TelePresence Class Supports:

2x CTS-3000 call at 1080p-Best over a
155 Mbps OC3 link

Network Control 5%
Call-Signaling 5%

Multimedia Streaming 5%

Multimedia Conferencing 5%
Broadcast Video 5%

Transactional Data 10%

*Traffic Allocations based on a 155 Mbps / OC3 Line Rate

Cisco Public

Cisco Sub-Line-Rate Access Design
Sub-Line-Rate Access Policy Overview
Metro
Ethernet
Network

HQoS Capable Switch
or Router

Sub-Line Rate
Ethernet
Access Circuit

Network-Facing
Provider Edges
(N-PE)

Trust DSCP
+ Queuing (CoS 4 & 5  PQ)

≤ 33% of
Shaped
Rate

Trust DSCP
+ Hierarchical QoS (HQoS) Shaping to Sub-Line Access Rate
+ PQ for CoS 5 (VoIP + Broadcast Video) within Shaped Rate
+ PQ for CoS 4 (Realtime Interactive) within Shaped Rate
+ Non-PQ for All Other Traffic Classes

Cisco Public

Cisco WAN QoS Designs At-A-Glance

http://www.cisco.com/en/US/technologies/tk543/tk759/technologies_white_paper0900aecd80295aa8.pdf
Cisco Public
http://www.cisco.com/en/US/docs/solutions/Enterprise/Video/qoswanaggasraag.html


Cisco Public

Thank you.


Cisco Public

QoS Monitoring


QoS Monitoring
» Ideal QoS monitoring should provide statistics on pre and post policy traffic and
traffic drops
» QoS policy validation : Does the right application/conversation have the right
network priority?
» Advanced monitoring tools can query the ‘CISCO-CLASS-BASED-QOS-MIB’ to collect
statistics for QoS policies
» NetFlow data carries information on QoS priority per conversation


SolarWinds NetFlow Traffic Analyzer


NetFlow Traffic Analyzer
Traffic

UDP NetFlow packets
reports on network
traffic including DSCP
QoS

SNMP poll collects
CBQoS data from
the CBQoS MIB

SolarWinds NTA

NTA Web GUI

NetFlow Traffic Analyzer
NetFlow Traffic Analyzer Features
» SolarWinds NTA : Add-On to SolarWinds Network Performance Monitor
» Leverages on flow technologies such as Cisco NetFlow, sFlow®, IPFIX, J-Flow to report on the
WHO, WHAT, WHEN and WHERE of network traffic
» Uses SNMP to report on the performance of your CBQoS policies

New Release: The Enhanced NTA 4.0
» NTA 4.0 comes with enhanced storage and reporting
» Store all collected flow data with 1 minute granularity forever!
» 5x more flow processing power and better load times during report generation

QoS Reporting with NTA
» Details about CBQoS policies applied on an interface including nested policies and
direction (inbound traffic vs. outbound traffic)
» Information on the amount of traffic before and after the effect of each QoS policy
» Pre and post policy statistics available for each class as well as for nested policies
» Drop traffic details – Amount of traffic dropped on an interface per QoS policy
including for each QoS class

» Helps validate the performance of your QoS policies

» NTA supports NetFlow v5 and Flexible NetFlow
» NetFlow data includes ToS information for
each IP conversation
» ToS (DSCP) field reporting in NTA can help
identify mismarked IP traffic
» NTA can report on protocol, applications, end
points and IP conversations under each ToS


Resources
Download a free fully functional 30-day trial at
solarwinds.com/nta

Video
Network Performance Monitor Overview
Intro to CBQoS Monitoring
All QoS features:
http://www.solarwinds.com/solutions/network-qos-report.aspx
Join our community of 150,000+ IT pros at www.thwack.com

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Cisco QoS: Design and Best Practices for Enterprise Networks

Cisco QoS: Design and Best Practices for Enterprise Networks

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