Microsoft PowerPoint - ASR1000 QoS ILT v4

© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialBasic ASR 1000 QoS 1

Cisco ASR 1000 SeriesQuality of Service

ASR 1000 Instructor Led Training: Train-The-Trainer

MRBU Marketing

March 2008


Objectives

� Understand the ASR 1000 QoS Hardware Implementation

–Gain insight on the classification, scheduling and buffering

–Understand the unique QoS capabilities of the ASR 1000

� Learn about the ASR 1000 QoS Software features and its roadmap


QoS: Introduction


Route Processor (standby)

Interconnect.

Embedded Service Processor

(active)

Interconnect.

Cisco QFP

Embedded Service Processor(standby)

Interconnect.

SPASPA …

Interconnect.

SPASPA …

Interconnect.

SPASPA …

Interconnect.

Midplane

Route Processor

(active)

Interconnect.

SPA-SPI, 11.2Gbps each directHypertransport, 8Gbps each direction

ESI, 11.5Gbps each direction

SIP10 ingress QoS

4 SPAs into 1 interconnect

40Gbps -> 10 Gbps

Interconnect QoS

3 SIP10 into 1 ESP10

30Gbps -> 10 Gbps

ESP10 Egress QoS

Cisco QFP into SPI 30Gbps -> 10 Gbps

Scheduled by ESP10 QPM

SIP10 egress QoS

10 Gbps into SIP10Up to 10Gbps

ASR 1000 Oversubscription

Ingress: 12 SPA:1 ESP10 oversubscription from ingress ports to QFP


ESP10

….....

Interconnect

Cisco QFP

SIP ( Ingress SIP )

Gig0/0/0 Gig0/0/1 Gig0/0/2 Gig0/0/3

Interconnect

This 10Gbps

link is not oversubscribed

SIP10 queues traffic from SPA into ingress buffers and then sends to ESP10

If 10Gig System Bandwidthis close to full OR if Cisco QFP is too busy then SIP10

may still send High Priority Traffic.

If these queues fill then SIP can send Queue Status back to specific SPA port

….....

High Low High Low High Low High Low

Queue status High and Low

Queue status High and Low

Ingress SPA

Ingress SPA Interface

Ingress SIP

If the queues fill then packets will tail drop or generate pause frames for Ethernet

ASR 1000 Ingress Scheduling


• QFP/BQS on active ESP is aware of and can receive queue status from all interfaces on all SPAs.

• QFP uses this status to control how USER/MQC Queues are serviced. QFP will not send more than the interface bandwidth.

• QFP can listen to both high and low priority queue status messages from egress queues on either the CC or SPA.

Either SPAs or SIP are constantly sending egressphysical/virtual port queue statusto both FP’s.

QFP is capable of accepting 10s of Millions of queue status updates / sec

ASR1000 QOS Main Scheduling (QFP/MQC)ESP 1

ESP 0

Queue status is also sent by the SIP to the Stanby FP

Gig0/0/0 Gig0/0/1 Gig0/0/2 Gig0/0/3

HI LO

HI LO

HI LO

HI LO

SIP

Egress SPA

HI LO

HI LO

HI LO

HI LO

Low Priority Traffic get queued

Lo Priority Queue �� FULL/XOFF

Hi Priority Queue �� OK/XON

Hi Priority Traffic gets Fastlane

Gig0/0/0 Congested for example:

Both Hi/Lo Q’s do not exist on Ethernet SPAs but do on other types of SPAs (shown here just for illustrative purposes).


QoS: Ingress SIP Overview


SPAs

ASR 1000 SIP10 Ingress QoS

ESI, 10Gbps)4 SPA’s

…

Ingress Buffers (per port)

Ingress H/L pkt

classifier

Ingress scheduler

…

Egress Buffers (per port)

Egress bfr status

reporting

11.2Gbps each

�Ingress packet priority classification

– Identifies ingress traffic as low- or high-priority traffic (both SIP and ESP will use this priority)

–Classifies based on 802.1P, IPv4 TOS, IPv6 TC, MPLS EXP

–Configurable per port or VLAN

� Ingress scheduler for selecting traffic to ESP10

–Default: Weighted Fair scheduling

–Min rate per port (optionally High priority only) and weight are configurable

–Excess BW sharing among ports

� Ingress buffering when ESP10 oversubscribed

–Accepts packets at line rate since memory is fast enough

– Two queues per port (H/L priority)

– Total ingress buffer pool is 128MB per SIP10

– Almost full buffer can generate ENET PAUSE, only HP by default

Interconnect

ESI, 10Gbps)

ESI

11.5 Gbps

FP1FP0

10Gbps (ESP10)


SIP10/SPA Ingress Classification Details

� Several options for ingress classification

MPLS EXP, IPv4 Prec/DSCP, IPv6 Prec/DSCP or 802.1p

� Priority determination either from SPA or SIP (depends on SPA type)

� Non-MQC CLI available for customization

plim qos input map ip dscp <dscp-value | dscp-range> queue < low-latency | 0>

� Otherwise, default classification is used for control packets


Example – Default Ingress classification

Router#show platform hardware interface te0/0/0 plim qos input map

Interface TenGigabitEthernet0/0/0

Low Latency Queue(High Priority):

IP PREC, 6, 7

IPv6 TC, 46

MPLS EXP, 6, 7

Router#show platform hardware interface Gig2/2/1.1 plim qos input map

Interface GigabitEthernet2/2/1.1

Low Latency Queue(High Priority):

COS, 6, 7

1. Default ingress classification for a physical interface

2. Default ingress classification for 802.1q subinterface


Examples of PLIM Match Commands

1. Map a range of values to an ingress queue

plim qos input map ip dscp af11-ef queue low-latency

2. Map all values to an ingress queue

plim qos input map mpls all queue 0

3. Map a list of values to an ingress queue

plim qos input map ipv6 tc cs4 cs5 queue low-latency

4. Map 802.1p value 5 to High Priority (VLANs only)

plim qos input map cos 5 queue low-latency


SIP10 Ingress Scheduling Details

� There are 2 queues ( high and low priority) per port

� There are two levels of scheduling per port per SIP10

1st level is to satisfy the Mininum BW config for the port

2nd level is for excess weight, i.e., dividing the remaining BW among ports based on configured weight

Optional: Specify that only the high priority gets min. BW guarantee per SIP10 or per port

� Non MQC CLI provided to customer for changing scheduling.

–plim qos input [bandwidth <value_in_Kbps> [ low-latency]] [weight <weight>]


Example – Ingress Scheduler Router#show platform hardware subslot 2/2 plim qos input bandwidth

Interface 2/2/0

BW : 1031040 Kbps, Min BW: 0 Kbps, Applied On Port, Excessive Weight: 1031000 Kbps

Interface 2/2/1


Interface 2/2/2


Interface 2/2/3


Interface 2/2/4


� Default behavior of the Ingress Scheduler for a 5*GigE SPA

No minimum bandwidth is assigned to any of the ports

Each port is assigned an excess weight proportional to interface BW

� Parameters are configurable via interface CLI commands

Min BW: plim qos input bandwidth 100000 low-latency

Weight: plim qos input weight 100

Pause frame generation: plim qos input queue 0 pause enable


ESP10 Interconnect Scheduler

� Ingress interconnect scheduler algorithm

Selects among SIP10 based on their Min BW and Weight

Within each SIP the scheduling is strict priority (High vs. Low)

� Configurable parameters

Minimum Bandwidth: 0 to 11.2 Gbps

Excess Weight: 10 to 40000

Configure Min BW to apply only to High Priority traffic

� Non MQC CLI is provided to change scheduling parameters

� QFP backpressures ingress schedulers to pace packet transfer rate

This is based on current QFP engine usage

There is a separate backpressure for high and low priority


Example – Interconnect Scheduler Router#show platform hardware slot F0 serdes qos

Qos Settings on FP:

slot # Min BW (Kbps) Min BW Mode Slot Weight

RP1 99975 HILO 256

RP0 99975 HILO 256

ESP1 99975 HILO 256

SIP2 49987 HILO 50

SIP1 49987 HILO 50

SIP0 49987 HILO 50

� This shows the default behavior of the Interconnect Scheduler

Each SIP is given a minimum bandwidth of ~50Mbps

This minimum bandwidth applies to both High & Low Priority traffic

Each SIP is given the same weight so excess BW is split equally among SIPs

� Each parameter is configurable via global CLI commands

Min BW: hw-module slot 2 qos input bandwidth 5000000

Mode: hw-module slot 2 qos input bandwidth 5000000 low-latency

Weight: hw-module slot 2 qos input weight 100


Ingress Scheduling – putting it all together

� Example

–2 10GigE core-facing SPAs on separate SIPs requiring a combined ~7Gbps of the available BW towards the ESP10

–1 10 x GigE access-facing SPA requiring a guarantee of 100Mbps per port and each port must get an equal share of remaining bandwidth once the 100Mbps contract is met

–Voice & Video must have priority over other types of traffic

–Voice & Video must get priority over other traffic for the minimum bandwidth guarantees, i.e., assume that we trust the packet marking


Ingress Queue Example:

10+ Gbps

10G

Gig

E

SP

A(H

H)

Cla

ssify

Em

pty

S

lot

Optional Min. BW = 3.6Gbps (HP only)2nd Level WRR

SIP0

10 G

bp

s

10G

Gig

E

SP

A(H

H)

Cla

ssify

Em

pty

S

lot

32MB / SPA

2nd Level WRR

SIP1

10 x 1 GigEE

mp

ty

Slo

t

1G

bp

sC

las

sify

1G

bp

sC

las

sify

1G

bp

sC

las

sify

1G

bp

sC

las

sify

1G

bp

sC

las

sify

1G

bp

sC

las

sify

1G

bp

sC

las

sify

1G

bp

sC

las

sify

1G

bp

sC

las

sify

1G

bp

sC

las

sify

32 MB / 10 x 1Gbps = 2.56 ms / GigE

2nd Level WRR

SIP2

Em

pty

S

lot

Em

pty

S

lot

Em

pty

S

lot

Cisco QuantumFlow Processor (QFP)E

mp

ty

Slo

t

Em

pty

S

lot

32MB / SPA

1st Level Min. BW / SIP

2nd Level WRR / SIP

10 G

bp

s.

10 G

bp

s

Min. BW =.1Gbps / Port (HP only)

ACCESSCORE

ESP10

Min. BW = 1Gbps (HP only)

Excess weight = 1

Min. BW = 3.6Gbps (HP only)

Excess weight = 1

Min. BW = 3.6Gbps (HP only)

Excess weight = 1

Optional Min. BW = 3.6Gbps (HP only)


QoS: ESP/QFP Overview


ESP10 Ingress and Egress QoS

1. Ingress packets are temporarily

stored in small internal pkt buffer

until processed

2. Free QFP Engine is allocated for this

packet and SW begins processing

packet (MAC classification, QOS

classification, ACL’s, forwarding

lookup, police, WRED, etc.) including

modifying packet contents

3. SW accesses tables in resource

DRAM and TCAM to perform lookups

for features enabled for this packet,

update statistics, update state for

stateful features, etc.

4. Once packet processing is complete

and packet has been modified, SW

issues request to enqueue packet to

an output queue

5. The packet contents is copied from

the internal pkt buffer to the deep

output packet buffer where it is

stored until scheduled for output From SIP10

Resource Memory

PPE0PPE0PPE0PPE1

TCAM4

PPE0PPE0PPE0PPE2

PPE0PPE0PPE0PPE5… PPE0PPE0PPE0PPE40

PPE0PPE0PPE0PPE3

Cisco QFP Engine

Packet Buffer

Memory

1

2

3

4

5

ESP10

Interconnect

Dispatcher / Buffer

Buffer, queue, schedule (BQS)

Buffer, queue, schedule (BQS)

Cisco QFP Traffic

Manager


BW scheduler

Interconnect

SPA

11G

ESP10

SPA…

6

ESP10 Ingress and Egress QoS

SIP10

1. Main output packet buffering in QFP

2. QFP HQF scheduler performs packet scheduling decisions

• Levels of hierarchy dynamically created to match MQC configuration

• Selects among class queues of an interface, among virtual interfaces on physical interface, among physical interfaces on a SIP10

• Enforces min, excess and max rates per queue and node

• High priority packets can pass lower priority packets in hierarchy (priority propagation)

3. BW scheduler allocates QFP output BW among SIP10's

• Selects among SIP10's with high priority packets first,

• If no high priority packets, then selects among SIP10's with low priority packets

4. Packet data transferred to SIP10's simultaneously over ESI

5. Shallow buffers on SIP10's and SPA – used to allow simultaneous packet transfer out multiple ports

6. Backpressure from shallow buffers used to control QFP scheduler at corresponding hierarchy node

…

11G

…

3

Egress Buffers

4ESI

Interconnect

Pkt Buffer Memory

QFP10

HQF scheduler

1

2

5

6


Which QoS features are done by PPEs?

� Cisco QFP PPE’s are in charge of all classification including NBAR, policing, WRED and other ingress QoS features (most of these are h/w accelerated)

� NBAR and FPM are easily done since the Cisco QFP can process the whole packet.

� Policing algorithm is a single- or double-rate, three-color policer. The Cisco QFP 10 supports the algorithm defined in RFC 2697 and RFC 2698.

� The bandwidth for policer calculations is similar to one used in 7200, which includes some of L2 overhead.

For Ethernet, we only include 14 byte (src mac, dst mac, type) but not the additional 24 byte ( gap, preamble, crc)


Which QoS features driven by PPEs are available at FCS?

1. Classification

� Precedence, DSCP, MPLS EXP, 802.1p, FR-DE, ACL

� HW-assist: TCAM

2. Marking

� Precedence, DSCP, MPLS EXP, 802.1p, FR-DE, discard-class, qos-group

� HW-assist: none, done in software

3. Policing

� 1 rate 3 color, 1 rate 2 color, percent-based policing

� HW-assist: Policing block in QFP

4. WRED

� Precedence, DSCP, discard-class

� HW-assist: WRED block in QFP


What is HQF?

� The Hierarchical Queuing Framework (HQF) describes an architecture/framework for implementing a hierarchical queuing system

� As such it does not specify the underlying algorithms that should be used

� Platforms may implement the framework with different levels of hierarchy and algorithms, with different resulting capabilities and behaviors

Just because two platforms both support HQF does not mean they support the same underlying functionality!!

� For the ASR1000 the QFP has a hardware queuing implementation that implements hierarchical scheduling

� HQF is also used to refer to the common control plane code in IOS that connects to MQC and provides APIs to the platform code

These APIs define MQC rules that ASR1000 and QFP Traffic managerfollow


What is a Schedule Hierarchy?

Queues

Schedules

Schedule EntriesRoot Schedule

classes

vlans

ports

Carrier card Scheduler’s client


QFP Traffic Manager / BQS highlights:

� 128K queues in ESP10 for network interfaces and internal interfaces (RP, crypto engine, recycled packets)

� 3 parameter scheduling: Max rate, min rate, excess weight

� 2 level of high priority traffic per policy

� Multiple levels for egress hierarchical queuing

� There’s backpressure/queue status at several levels: ESI, SIP10 and some SPAs

� This in addition to the MQC classes, becomes a multilayer hierarchy:

– MQC Levels + SPA + SIP10 + ESI

� Packet buffering equivalent to 100ms

– ESP-5G: 64MB

– ESP-10G: 128MB

– ESP-20G: 256MB


QFP Scheduling Feature Roadmap

RLS0 RLS1 RLS2 RLS3

Multiple Priority Queues ��

Shaping ��

Shape per BB Session X X ��

Bandwidth ��

BRR* ��

BRP* X X ��

Priority Propagation ��

Min BW Propagation X X X X

Conditional Policer X X ��

Fragment CLI/Economy Class Rate

��

3-Level H-QoS X ��

4-Level H-QoS X X X ��


QFP Priority Queuing

� Two Levels of Priority Queues (PQ)

Priority Level 1 traffic served before Priority Level 2 traffic

Priority Level 2 traffic served before non-priority traffic

Priority is “propagated” through the hierarchy

� What does Priority Propagation mean?

Priority level defined at the class layer in the hierarchy propagates to logical and physical layers

� Priority Queuing + Priority Propagation = low latency as long aspriority traffic is not oversubscribed

Explicit Policer can be used to cap priority traffic in a class

Conditonal Policer can be used to cap priority traffic when congestion is detected on the output interface

� Two levels of PQ allows optimized support for Voice and Video


QFP Priority Queuing cont.

� SPA+SIP10+QFP status communication ensures that Priority traffic is protected

QFP is aware of and can receive queue status from all interfaceson all SPAs

QFP uses this status to control how the MQC Queues are serviced

QFP will not send more than the interface bandwidth

QFP can also listen to both high and low priority queue status messages from egress queues on either the SIP10 or SPA


QFP Shaping

� Shaping uses the traditional token bucket algorithm with its burst parameters

� Shaping bandwidth calculation is same as policer, with some L2 overhead


QFP Weighted Queuing

� QFP supports weighted queuing at all levels of a hierarchy

Within a SIP � among physical interfaces

Within a physical interface � among logical interfaces

Within a logical interface � among class queues

� Weights are compared against peer nodes


Weighted Queuing Example -VLAN 89/9/1 MQC Configuration

interface FastEthernet1/1/3.100interface FastEthernet1/1/3.100interface FastEthernet1/1/3.100interface FastEthernet1/1/3.100encapsulation dot1Q 100encapsulation dot1Q 100encapsulation dot1Q 100encapsulation dot1Q 100ip address 103.1.100.1 255.255.255.0ip address 103.1.100.1 255.255.255.0ip address 103.1.100.1 255.255.255.0ip address 103.1.100.1 255.255.255.0serviceserviceserviceservice----policy output vlan100policy output vlan100policy output vlan100policy output vlan100Policy Map vlan100Policy Map vlan100Policy Map vlan100Policy Map vlan100

Class classClass classClass classClass class----defaultdefaultdefaultdefaultbandwidth remaining ratio 89bandwidth remaining ratio 89bandwidth remaining ratio 89bandwidth remaining ratio 89



0

20000

40000

60000

80000

100000

120000

140000

160000

0 3 6 9 12 15 18

vlan

100

vlan

101

vlan

102



PPS


Example – Check default QFP TM buffer/queue limit

Router# sh plat ha cpp act inf bqs qu out de int GigabitEthernet2/0/2

Interface: GigabitEthernet2/0/2, CPP if_h: 9, Num Queues/Schedules: 1

Queue specifics:

Index 0 (Queue ID:0x32, Name: )

Queue Info:

(cache) queue id: 0x00000032, wred: 0x88b01802, qlimit: 0x0002faf2

Statistics:

tail drops (octets): 0 , (packets): 0

total enqs (octets): 0 , (packets): 0

queue_depth (bytes): 0

• Above shows the default queue limit 0x0002faf2 (195314)• This value is actually a multiple of 32 bytes• 195314 * 32 bytes * 8 bits = ~50 Mb … so about 50ms for a GigE link


QFP Hierarchy Overview

� Three level H-QoS on an Ethernet interface

1. Class � Defined via MQC

2. Logical � VLAN sub-interface

3. Physical � Ethernet Interface

� Keep in mind that in QFP there are added levels to represent theegress SIP card and the ESI links … so it is actually 5 levels!

VLAN X

VLAN 1

Class A

Class C

Class B

Port 1

Port 2


QFP Hierarchy Example 1

Sample 2 level (Class + physical) hierarchy QoS configuration

Policy-map PARENTclass class-defaultshape average 200 Mbpsservice-policy output CHILD

Policy-map CHILDclass EF

set cos Xpriority level 1

class AF4set cos Xpriority level 2

class AF1random-detect dscp-basedrandom-detect af11 100 1000random-detect af12 100 700bandwidth remaining ratio 9

class class-defaultbandwidth remaining ratio 1

Interface gigabitethernet 0/1.1001service-policy output PARENT

SIPn

10GE210GE1

EF

AF

4

AF

1

Defa

ult


SIPn

GE1 GEyGE2

…

P1 passes P2

…

“bandwidth remaining ratio ” for AF1 and default performed here

P1 passes P2, P2 passes Data

BW Node

BQ

Squ

eue


shape average <parent policy > enforced here

VLAN1

EF

AF

4

AF

1

Defa

ult

VLAN2

EF

AF

4

AF

1

Defa

ult

VLAN X

EF

AF

4

AF

1

Defa

ult

Sample 3 level (class + VLAN + physical) hierarchy config

Interface Gigabitethernet 1/1/0.1service-policy output PARENT


….



QFP 3-level Hierarchy Unique to ASR

� Requirements were for a subscriber QoS Model

1000 subscribers (VLAN-based) sharing a GigE port – Triple Play scenario

Subscriber data traffic should be capped at interface level

Voice/Video traffic to be CAC’ed at interface level and serviced in priority order

� Existing 3-level hierarchy could not handle it

No way to aggregate only data traffic at interface level – interface shaper would shape ALL traffic

Shaper at VLAN level would shape ALL subscriber traffic (Voice/Video/Data)

� Physical & logical interface policies linked via new “fragment CLI”

Benefit: Data classes can be linked together to provide both VLAN level and aggregate level service

� Priority queues are separated from the Data queus in the hierarchy

Benefit: Priority traffic is not capped by logical interface shaper

� Introduces the concept of an Economy Class Rate

Think of airline model: data traffic stays within its assigned class of service all through the hierarchy

First class traffic (like voice/video) is not affected by this rate


AF

1

…VLAN1

EF

AF

4

VLAN2

EF

AF

4

VLANxE

F

AF

4

Data

SIPn

GE1 GEy…

…

VLAN1

AF

1

VLAN2 VLANx

AF

1

…

BW Node

BQ

Squ

eue


Defa

ult

Defa

ult

Defa

ult

ASR 1000 Exclusive Hierarchy

Priority

4 Level Hierarchy:

1. Class -> MQC defined

2. Logical -> VLAN

3. Aggregate -> Service

4. Physical -> GigE


QFP Hierarchy Example 3 cont.

Policy-map main-interfaceClass data service-fragment BEshape average 400 Mbps

policy-map SUBSCRIBER1class EF

priority level 1class AF4

priority level 2class class-default fragment BE

shape average 100 Mbpsbandwidth remaining ratio 1service-policy AF1plusDefault

Aggregate Economy Class Rate

LIN

KE

D

policy-map SUBSCRIBERNclass EF

priority level 1class AF4

priority level 2class class-default fragment BE

shape average 150 Mbpsbandwidth remaining ratio 2service-policy AF1plusDefault


QFP Packet Buffers

� QFP Packet Buffer DRAM treated as one large buffer pool

No pools based on packet size nor are buffers assigned to interfaces

� Two main building blocks for packet buffer DRAM

“Block”: each queue gets 1KB blocks of memory for enqueued pkts

“Particle”: packets are divided into 16 byte particles and linked together

� Several advantages to such an implementation

Less complex than buffer carving schemes

Fragmentation is minimal & predictable due to small sized blocks & particles

� Thresholds exist to protect internal control traffic and priority traffic

� Queue-limit considerations

Requires careful tuning of queue-limit parameter to avoid scenarios where a small number of queues occupy most of the buffer space


QFP Packet Buffers - Example

Start of

Block #2

Start of

Block #1

P1 P1 P1 P1 P1 P1 P1 P1 P1 P1 P1 P1 P1 P1 P1 P1



P4 P4 P4 P4 P4 U U U U U U U U U U U




P5 P5 P5 P5 P5 P5 P5 P5 P5 P5 P5 P5 U U U U

� Simple example demonstrating block/particle concepts

Two blocks (could be two different queues)

Five enqueued packets total


Example – Egress SIP Queues router#show platform hardware slot 2 plim buffer settings detail

Interface 2/2/0

RX : : Size 2064384 Drop Threshold 2063424 Byte Fill Status ( 0/ 0) Byte

Almost Empty TH0/TH1 1011264 Byte / 1020864 Byte

Almost Full TH0/TH1 2022528 Byte / 2032128 Byte

SkipMe Cache Start / End Addr 0x0000A800 / 0x0000B240

Buffer Start / End Addr 0x01FAA000 / 0x021A1FC0

TX : : Size 48 , Drop Threshold 35136 Byte, Fill Status ( 0/ 0) Byte

Event XON/XOFF 3840 Byte / 7200 Byte

Buffer Start / End Addr 0x00000300 / 0x0000032F

RX : : Size 2064384 Drop Threshold 402624 Byte Fill Status ( 0/ 0) Byte

Almost Empty TH0/TH1 180864 Byte / 190464 Byte

Almost Full TH0/TH1 361728 Byte / 371328 Byte

SkipMe Cache Start / End Addr 0x0000B280 / 0x0000BCC0

Buffer Start / End Addr 0x021A2000 / 0x02399FC0

TX : : Size 48 , Drop Threshold 35136 Byte, Fill Status ( 0/ 0) Byte

Event XON/XOFF 3840 Byte / 7200 Byte

Buffer Start / End Addr 0x00000330 / 0x0000035F

� Egress SIP buffer thresholds are not configurable


QoS: Software Feature Overview


ASR 1000 QoS feature support� ASR 1000 SW QoS features are mainly from 12.2SR,

but it also has NBAR from 12.4T

� This includes the latest 12.2S QoS features

–MQC CLI

–Multiple Priority Queues

–Bandwidth Remaining Ratio

� All of the platform Ingress QoS CLI commands

–“plim qos input map …”

–“hw-module slot X qos input”


RP1

Forwarding Information PathTransit DataLegend

Forwarding Manager

Cisco IOS

Forwarding Manager

Cisco QFP Client/Driver

ESP 10

Cisco QFP

Cisco QFP Datapath

Embedded Service Processor

Forwarding

CPU

Interconnect

Cisco

QFP

Encryption

Engine

Route Processor

Route ProcessorCPU

Software View System View

Interconnect

ASR 1000 QoS feature support


Migrating to ASR 1000 QoS

� Existing QoS configuration

Policy child-output

class EF

priority 5 mbps

class AF

bandwidth 50 mbps

class class-default

bandwidth 45 mbps

Policy parent-output

class class-default

shape average 100 mbps

service-policy child-output

� ASR 1000 alternative

Policy child-output

class EF

priority level 1

police 5 mbps

class AF

bandwidth remaining ratio 50

class class-default

bandwidth remaining ratio 45

Policy parent-output

class class-default

shape average 100 mbps

service-polcy child-output

� In many cases it will be necessary to migrate an existing QoS config to an ASR1000 equivalent which matches desired behavior


Bandwidth Remaining Percentage vs. Ratio

BRR

� Parameter is unitless

� Part of ratio that changes with addition of classes

� Inconvenient when trying to figure out % for each class

� Convenient with a very dynamic class configuration

� Convenient with dynamic configurations with more than 100 vlans/classes

BRP

� Parameter is a percentage

� Total % for all classes/levels can’t be more than 100%

� Convenient when a class must always get same %

� Inconvenient with a very dynamic class configuration

� Convenient with traditional configurations with few and very static vlans/classes


ASR 1000 QoS Scalability

QoS features ASR 1000

Global Policies 1024 (IOS limit)

Global Class-maps 256-1K (ASR 1000 limit)

Class-maps/policy 8 ( ASR 1000 limit)

Queues 128K ESP-10

Policer/shaper accuracy 1%

Policer/shaper granularity

8 Kbps ( IOS limit )


ASR 1000 QoS Summary

� Cisco ASR 1000 Series Routers are designed to perform under highly oversubscribed conditions, with SIP10 ingress classification and scheduling and Cisco QFP flexible scheduler

� As long as high priority traffic does not oversubscribe ESP10 bandwidth, it will reach Cisco QFP for processing and will be transmitted before any other traffic.

� The Cisco ASR 1000 Series Router software architecture is flexible for the rapid implementation of the latest Cisco IOS MQC QoS features.

� The QoS architecture of the Cisco ASR 1000 Series and Cisco QFP satisfies all the voice, video and data requirements in today’s distributed networks and their future generations.

Documents

Microsoft PowerPoint - ASR1000 QoS ILT v4