1. Deploying QoS for Enterprise Network Infrastructures Mark Montañez Enterprise Solutions Engineering Design Team: CANI - QoS

2. Session Objectives
To be able to design and implement a converged voice, video, and data network that can guarantee voice quality while enabling video conferencing and mission critical data applications
More information available here:
QoS SRND
IP Tel SRND

3. The Enterprise Network Design Model
The OSI Stack Revisited
Business Layer
Application Layer
Highly Available, QoS-Enabled Infrastructure Layer

4. 3 Steps for Implementing QoS
Classification—Marking the packet with a specific priority denoting a requirement for special service from the network
Scheduling—Assigning packets to one of multiple queues (based on classification) for preferential treatment throughout the network
Provisioning—Accurately calculating the required bandwidth for all applications plus element overhead

5. QoS Is Needed to Minimize Packet Loss, Delay and Delay Variation
Where QoS Is Needed
Central Campus
Remote Branch
WAN
QoS—Campus Access
Graphics not bleeding to edge of slide
QoS—Campus Dist.
QoS—WAN
QoS—Branch
Speed and duplex settings
Classification/trust on IP phone, VC station, content service, and Citrix server
Multiple queues on IP phone and access ports
Layer 3 policing for content distribution
Multiple queues on all ports; priority queuing for VoIP
WRED within data queues for congestion management
Low-latency queuing
Data traffic queue provisioning
Link fragmentation and interleave
Traffic shaping
Admission control
Speed and duplex settings
Classification/trust on IP phone, VC station, Content service and Citrix traffic
Multiple queues on IP phone and access ports

6. Agenda
Quality Concerns with IP Telephony, Multimedia Applications and Mission-Critical Data
General Enterprise QoS Design Considerations
Connecting the End-Points
Designing the Campus
Enabling the WAN
QoS Impact
VoIP and the Telecommuter
Questions and Answers
Summary

7. Example of PCM (64Kbps) IP Telephony Call
Single PCM VoIP Call
Consistent, easily managed packet rate (default 50pps)
A G.711 call is really ~80Kbps over a data network
Packet loss
Current Cisco GW DSP CODEC algorithms can correct for 30 msec of lost voice—1 G.729A voice packet contains 20 msec of voice
One lost FAX over IP packet causes a MODEM retrain; 2 drops cause a call disconnect
Causes of packet loss: Network quality, network congestion and delay variation (jitter buffer under-runs and over-runs)

8. Example of 384 Kbps Video (30 fps) Conferencing Traffic (CIF)
“I” Frame
1024–1518
Bytes
“I” Frame
1024–1518
Bytes
600Kbps
30pps
“P” and “B” Frames
128–256 Bytes
15pps
32Kbps
“I” frame is a full sample of the video
“P” and “B” frames use quantization via motion vectors and prediction algorithms

9. Video Conferencing Traffic Packet Size Breakdown (CIF)
1025–1500 Bytes 37%
65–128 Bytes 1%
129–256 Bytes 34%
513–1024 Bytes 20%
257–512 Bytes 8%

10. Some Applications that Require QoS
Citrix
DLSw+
PeopleSoft
Oracle
ERP— underlying apps
PC replication/ multicast applications
Video distribution
FTP
Batch updates
Backups
Napster
KaZaa
Morpheus
Grokster

11. Provisioning for Data: General Principles
Profile applications to their basic network requirements
Don’t over-engineer provisioning
Use proactive policies before reactive (policing) policies
Seek executive endorsement of relative ranking of application priority prior to rolling out QoS policies for data

12. Agenda
Quality Concerns with IP Telephony, Multimedia Applications and Mission-Critical Data
General Enterprise QoS Design Considerations
Connecting the End-points
Designing the Campus
Enabling the WAN
QoS Impact
VoIP and the Telecommuter
Questions and Answers
Summary

13. Layer 2 and 3 Traffic Classification
Layer Q/p
TAG 4 Bytes
PREAM.
SFD DA SA
Type PT
DATA
FCS
Three Bits Used for CoS
(802.1D User Priority)
PRI
CFI
VLAN ID
Layer 3 IPV4
Version
Length
ToS 1 Byte
Len ID
Offset
TTL
Proto
FCS
IP-SA
IP-DA
Data 7 6 5 4 3 2 1
IP Precedence
Flow Control
for DSCP
DSCP
Standard IPV4: Three MSB Called IP Precedence
(Diffuser May Use Six D.S. Bits Plus Two for Flow Control)

14. Diffuser Code Points (DSCP)
Diff-Serv Behaviors
Per-Hop Behaviors (PHB)
Diffuser Code Points (DSCP)
Expedited Forwarding EF
101110
Assured
Forwarding
Low Drop Prêt
Med Drop Prêt
High Drop Prêt
Class Selector (CS) 4
AF41
AF42
AF43
Class Selector (CS) 3
AF31
AF32
AF33
Class Selector (CS) 2
AF21
AF22
AF23
Class Selector (CS) 1
AF11
AF12
AF13
Best Effort
000000

15. Diffuser Code Points (DSCP)
Diff-Serv Behaviors
Per-Hop Behaviors (PHB)
DSCP
<BE1
<BE2
<BE3 BE
AF11
AF12
AF13
AF21
AF22
AF23
AF31
AF32
AF33
AF41
AF42
AF43 EF
Decimal 2 4 6 10 12 14 18 20 22 26 28 30 34 36 38 46
Binary
000010
000100
000110
000000
001010
001100
001110
010010
010100
010110
011010
011100
011110
100010
100100
100110
101110
IP PREC 1 3 5
000
001
010
011
100
101
Diffuser Code Points (DSCP)
Expedited Forwarding EF
101110
Assured
Forwarding
Low Drop Prêt
Med Drop Prêt
High Drop Prêt
Class Selector (CS) 4
AF41
AF42
AF43
Class Selector (CS) 3
AF31
AF32
AF33
Class Selector (CS) 2
AF21
AF22
AF23
Class Selector (CS) 1
AF11
AF12
AF13
Best Effort
000000

16. Designing the Campus General Guidelines
A robust, modern switching design is a requirement
Designing High-Performance Campus Intranets with Multilayer Switching
Gigabit Campus Design
Gigabit Campus Network Design— Principles and Architecture
Multiple queues are required on all interfaces to prevent TX queue congestions/drops
RTP bearer traffic should always go into the highest priority queue; control should go into separate queue

17. Building the Branch Office
General Guidelines
The WAN branch router must support advanced Cisco QoS tools
Map between layer 2 and layer 3 classification schemes
Use a branch switch with multiple queues
802.1Q trunking between the router and switch for multiple VLAN support (separation of voice/data traffic) is preferred

18. Enabling the WAN General Guidelines Queuing
QoS Enabled
WAN
Queuing
Use CBWFQ for data on all WAN interfaces in a converged network
LLQ for VoIP and video conferencing
Traffic shaping is required for all frame-relay and ATM/FR networks
If running VoIP, use LFI on WAN connections below 768Kbps
Don’t use LFI on any video over IP solutions with VoIP
Use cRTP carefully

19. VoIP Over IPSec VPNs General Guidelines VPN
Crypto is a FIFO queue, so:
Take steps to not over drive the crypto engines capabilities (CAR, skip crypto for voice, new code coming, etc.)
Use pre-classify when more than ToS byte used for classification
If using IP mc MoH, IPSec GRE tunnel is required
cRTP does not work w/IPSec
See ESE SOHO VPN QoS Design Guide (Part of QoS SRND)
See ESE Web Site V3PN Design Guide (available through your SE)

20. Agenda
Quality Concerns with IP Telephony, Multimedia Applications and Mission-Critical Data
General Enterprise QoS Design Considerations
Connecting the End-Points
Designing the Campus
Enabling the WAN
QoS Impact
VoIP and the Telecommuter
Questions and Answers
Summary

21. Classification Tools: Trust Boundaries
Endpoints
Access
Distribution
Core
WAN Agg. 1 2 3
Trust Boundary
A device can be trusted if it correctly classifies packets
For scalability, classification should be done as close to the edge as possible
The outermost trusted devices represent the trust boundary
1 and are optimal, 3 is acceptable (if access switch cannot perform classification) 1 2 3

22. PC CoS Settings Are Not Trusted
IP Phone Switch ASIC
Untrusted: Phone ASIC Will Re-Write CoS 0
COS = 5
COS = 5
COS = 7
COS = 0
set port qos <mod/port> trust-ext _____
Only applies to port trust on the IP phone PC Ethernet port
Un-related to actual cat6k port trust
set port qos <mod/port> trust ____
Applies to the actual switch port trust rules
untrusted (default), trust-cos, trust-ipprec, trust-dscp
Some 6k 10/100 cards require an additional ACL to actually enable port trust

23. Connecting the Video Conferencing Stations
L3 Aware
Watch physical speed/duplex settings/negotiation
Trust classification of known room systems but filter on assigned IP address; VC station is in a conference room where anyone has access to the Ethernet port
Use H.323 proxy to classify traffic from PC-based VC for admission to WAN PQ
All video conferencing traffic should be set to DSCP AF41

24. Integrating DLSw+
L3 Aware
Default is IP Precedence 5 with no configuration; can cause PQ over subscription if not accounted for
trust-ipprec from router generating DLSw+ traffic
Use the dlsw remote-peer priority to use the different DLSw+ ports; change the default DLSw+ IP Prec mapping
dlsw remote-peer 0 tcp priority
dlsw tos map high 2 medium 2 normal 2 low 2
DLSw+ is not DSCP aware so we can only set the IP Precedence; admission to mission critical class needs to take this into account
Place in bandwidth defined class-based weighted fair queue

25. Agenda
Quality Concerns with IP Telephony, Multimedia Applications and Mission-Critical Data
General Enterprise QoS Design Considerations
Connecting the End-Points
Designing the Campus
Enabling the WAN
QoS Impact
VoIP and the Telecommuter
Questions and Answers
Summary

26. Is QoS Needed in the Campus?
“Just throw more bandwidth at it. That will solve the problem!”
Transmit Buffer Management Is Just as Important as Bandwidth Management

27. Transmit Queue Congestion—WAN
Queued
128k Uplink
WAN
Router
100 meg in 128 kb/s out—packets serialize in faster than they can serialize out
Packets queued as they wait to serialize out slower link

28. Transmit Queue Congestion—LAN
1 Gig Link
Queued
100 Meg Link
Distribution Switch
Access Switch
1 gig in 100 meg out—packets serialize in faster than they can serialize out
Packets queued as they wait to serialize out slower link
Many access ports aggregated into single distribution link; instantaneous periods of congestion

29. Transmit Queue Congestion— The Answer
Multiple queues allow us to protect the queue containing important traffic from drops
Drops happen in BE only queue(s)
Queue Mgr
Queue 1
Queue 2
RR/WRR/PQ
Queue Scheduler
Round Robin, Weighted Round Robin or Priority Queuing Used for Scheduling between Queues
Data
Voice

30. Transmit Queue Visibility
Queue Mgr
RR/WRR/PQ
Queue Scheduler
Queue 2
Voice
Data
Queue 1
Cat 6k CatOS - show qos statistics 4/1
Cat 4500 SupIV - show int fa3/2 count all
Cat 3550 – show mls qos int statistics fa3/2

31. Transmit Queue—Visibility 4500 SUPIV
Queue Mgr
RR/WRR/PQ
Queue Scheduler
Queue 2
Voice
Data
Queue 1
4006-SUPIII-Access#sh int g3/2 count all .
Port InPkts OutPkts
Gi3/
Port Tx-Bytes-Queue-1 Tx-Bytes-Queue-2 Tx-Bytes-Queue-3 Tx-Bytes-Queue-4
Gi3/
Port Tx-Drops-Queue-1 Tx-Drops-Queue-2 Tx-Drops-Queue-3 Tx-Drops-Queue-4
Gi3/
Port Rx-No-Pkt-Buff RxPauseFrames TxPauseFrames PauseFramesDrop

32. Access Layer Classification and Scheduling
Required towards Phone and Distribution Layer
Core
QoS Required
Distribution
Access

33. Queuing/Scheduling Capabilities Depend on Hardware:
Campus QoS
Catalyst Switches which Support Multiple Queues
Queuing/Scheduling Capabilities Depend on Hardware:
Access
2900/3500—2Q1T
2950 4Q (priority schedule or WRR)
3550—1P3Q2T or 4Q2T
4000/SUPII—2Q1T
4500/SUPIV—1P3Q2T (priority config)
6500—2Q2T TX (10/100 classic)
1Q4T RX (10/100 classic)
1P2Q2T TX (gig classic)
1P1Q4T RX (gig classic)
Distribution/core
4500/SUPIV—1P3Q2T
6500—2Q2T TX (10/100 classic)
1Q4T RX (10/100 classic)
1P2Q2T TX (gig classic)
1P1Q4T RX (gig classic)
1P3Q1T TX (10/100 fabric)
1P1Q RX (10/100 fabric)
1P2Q1T TX (gig fabric)
1P1Q8T RX (gig fabric)

34. Queuing/Scheduling Capabilities Depend on Hardware:
Campus QoS
Catalyst Switches which Support Multiple Queues
Queuing/Scheduling Capabilities Depend on Hardware:
1P2Q2T
1P2Q2T—One priority queue
1P2Q2T—Two additional queues
1P2Q2T—Two drop thresholds for each queue
2Q2T
2Q2T—Two queues
2Q2T—Two drop thresholds for each queue

35. QoS in Catalyst 3550 4 transmit queues (1P3Q2T or 4Q2T)
Need to configure PQ and insure that CoS 5 traffic serviced via PQ
Configurable PQ for 4th queue
priority-queue out
Configurable CoS to specific queue
wwr-queue 4 5
Configurable queue depth (expert mode)
Configurable queue weight (expert mode)
802.1p, DSCP or ACL-based QoS
Trust DSCP, or CoS (policy maps)
Can set DSCP or CoS by port (marked/rewrite or unmarked)
Mapping from CoS to DSCP/DSCP to CoS
Now shipping with inline power
6500
6500
3550
3550
3550

36. Catalyst 3550 Example Access Layer—Access Port and Uplink
mls qos map cos-dscp
mls qos !
interface GigabitEthernet0/12
description Uplink to Distribution
no ip address
flowcontrol send off
mls qos trust dscp
wrr-queue cos-map 4 5
priority-queue out
interface Fastthernet0/1
description to IP Phone
mls qos trust CoS
switchport voice vlan 111
switchport access vlan 11
switchport priority extend cos 0
6500
6500
Boldface and animation
3550
3550
3550

37. Catalyst 3550 Example Access Layer—Classification 6500 6500
mls qos map cos-dscp
mls qos !
class-map match-all VoIP-Bearer
match access-group name VoIP-Bearer
class-map match-all Mission-Critical
match access-group name Mission-Critical
class-map match-all VoIP-Control
match access-group name VoIP-Control
policy-map VoIP-Policy
class VoIP-Control
set ip dscp 26
class VoIP-Bearer
set ip dscp 46
class Mission-Critical
set ip dscp 18
interface GigabitEthernet0/1
description Classification
no ip address
flowcontrol send off
service-policy in VoIP-Policy
wrr-queue cos-map 4 5
priority-queue out
6500
6500
Boldface and animation
3550
3550
3550

38. QoS in Catalyst 4500—Access (SUPIV)
4 queues (1P3Q2T or 4Q2T)
Need to configure PQ and insure that CoS 5 traffic serviced via PQ
Configurable PQ for 3rd queue
tx-queue 3
Priority high
Configurable queue depth (expert mode)
Configurable queue weight (expert mode)
802.1p, DSCP or ACL-based QoS (policy maps)
Can set DSCP or CoS by port (marked/rewrite or unmarked)
Trust DSCP or CoS
Mapping from CoS to DSCP/DSCP to CoS
4500 shipping with inline power (no PEM)
4000SUPIII

39. Catalyst 4000 (SUPIII) Example
Access Layer—Access Port and Uplink
qos map cos 1 to dscp 10
qos map cos 2 to dscp 18
qos map cos 3 to dscp 26
qos map cos 4 to dscp 34
qos map cos 5 to dscp 46
qos !
interface GigabitEthernet1/1
description Uplink to Distribution
qos trust dscp
no snmp trap link-status
tx-queue 3
priority high
interface FastEthernet4/1
description To IP Phone
qos trust cos
switchport voice vlan 111
switchport vlan 11
switchport priority extend cos 0
Core
Distribution
Access
4000
Cleanup with annimations and build-out

40. Catalyst 4000 (SUPIII) Example
Access Layer—Classification
qos map cos 1 to dscp 10
qos map cos 2 to dscp 18
qos map cos 3 to dscp 26
qos map cos 4 to dscp 34
qos map cos 5 to dscp 46
qos !
class-map match-all VoIP-Bearer
match access-group name VoIP-Bearer
class-map match-all Mission-Critical
match access-group name Mission-Critical
class-map match-all VoIP-Control
match access-group name VoIP-Control
policy-map VoIP-Policy
class Mission-Critical
set ip dscp 18
class VoIP-Control
set ip dscp 26
class VoIP-Bearer
set ip dscp 46
interface GigabitEthernet1/1
qos trust cos
service-policy in VoIP-Policy
tx-queue 3
priority high
Core
Distribution
Access
4000
Cleanup with annimations and build-out

41. QoS in 6500 Switches—Access (PFC)
Redundant SUP’s, transmit and receive queues, priority queues and multiple drop thresholds
802.1p, DSCP or ACL-based QoS (policy maps)
Trust DSCP or CoS
Can set by port DSCP or CoS (marked/rewrite or unmarked)
Mapping from CoS to DSCP/DSCP to CoS
Port can trust DSCP, IP Prec or CoS
Recommended: trust-cos (access to RX PQ)
10/100 cards require an additional step of configuring ACL to trust traffic
Output scheduling consists of:
Assigning traffic to queues based on CoS
Configuring threshold levels
Modifying buffer sizes (expert mode)
Assigning weights for WRR (expert mode)
6500

42. Catalyst 6500 Example Access Layer—Catalyst 6000 Access
cat6k-access> (enable) set qos enable
cat6k-access> (enable) set qos cos-dscp-map
cat6k-access> (enable) set qos ipprec-dscp-map
cat6k-access> (enable) set qos map 1p2q2t tx 2 1 cos 3
cat6k-access> (enable) set qos map 2q2t tx 2 1 cos 3
cat6k-access> (enable) set port qos 5/1-48 trust trust-cos
cat6k-access> (enable) set port qos 5/1-48 cos-ext 0
cat6k-access> (enable) set port qos 5/1-48 vlan-based
cat6k-access> (enable) set qos acl ip ACL_IP-PHONES trust-cos ip any any
cat6k-access> (enable) commit qos acl all
cat6k-access> (enable) set qos acl map ACL_IP-PHONES 110
cat6k-access> (enable) set port qos 1/1-2 trust trust-cos
Access
4000
Need to add citrix and dlsw server

43. Distribution Layer Classification and Scheduling
Required to/from Access Layer
Core
QoS Required
Distribution
Access

44. QoS in Catalyst 4500— Distribution (SUPIV)
4 queues (1P3Q2T or 4Q2T)
Need to configure PQ and insure that CoS 5 traffic serviced via PQ
Configurable PQ for 3th queue
tx-queue 3
Priority high
Configurable queue depth (expert mode)
Configurable queue weight (expert mode)
802.1p, DSCP or ACL-based QoS (policy maps)
Trust DSCP or CoS
Can set by port DSCP or CoS (marked/rewrite or unmarked)
Mapping from CoS to DSCP/DSCP to CoS
Careful w/over-subscribed cards—32g max
4006 w/SUPIII

45. Catalyst 4500 (SUPIV) Example
Distribution Layer—Downlink
Core
qos map cos 1 to dscp 10
qos map cos 2 to dscp 18
qos map cos 3 to dscp 26
qos map cos 4 to dscp 34
qos map cos 5 to dscp 46
qos !
interface GigabitEthernet4/1
qos trust cos
no snmp trap link-status
tx-queue 3
priority high
interface GigabitEthernet4/2
qos trust dscp
Distribution
Access
4000

46. QoS in 6500—Distribution
Redundant sups, transmit and receive queues, priority queues and multiple drop thresholds
CoS, DSCP or ACL-based QoS (policy maps)
Trust DSCP or CoS
Can set by port DSCP or CoS (marked/rewrite or unmarked)
Mapping from CoS to DSCP/DSCP to CoS
Port can trust DSCP, IP Prec or CoS
Recommended: trust-cos (access to RX PQ)
10/100 cards require an additional step of configuring ACL to trust traffic
Output scheduling consists of:
Assigning traffic to queues based on CoS
Configuring threshold levels
Modifying buffer sizes (expert mode)
Assigning weights for WRR (expert mode)
6500

47. Catalyst 6500 Example—Hybrid
Distribution Layer—Catalyst 6000
Hybrid
6500
cat6k-distrib> (enable) set qos enable
cat6k-distrib> (enable) set qos ipprec-dscp-map
cat6k-distrib> (enable) set qos cos-dscp-map
cat6k-distrib> (enable) set qos map 1p2q2t tx queue 2 1 cos 3
cat6k-distrib> (enable) set qos map 2q2t tx queue 2 1 cos 3
cat6k-distrib> (enable) set port qos 1/1-2 trust trust-cos
cat6k-distrib> (enable) set port qos 3/2 trust trust-dscp
cat6k-distrib> (enable) set port qos 9/1 trust trust-dscp
cat6k-distrib> (enable) set port qos 9/1 port-based
cat6k-distrib> (enable) set qos acl ip ACL_TRUST-WAN trust-dscp ip any any
cat6k-distrib> (enable) commit qos acl ACL_TRUST-WAN
cat6k-distrib> (enable) set qos acl map ACL_TRUST-WAN 9/1
Still need more detail for Mission Critical Applications
Rework slide… explination of what we are doing

48. Catalyst 6500 Example—Native
Distribution Layer—Catalyst 6000
mls qos
mls qos map ip-prec-dscp
mls qos map cos-dscp
int range gigabitEthernet 1/1 - 2
wrr-queue cos-map 2 1 3
wrr-queue cos-map 2 2 4
! Trust DSCP from the Layer-3 aware enabled Access Switch
interface GigabitEthernet2/1
description trunk port to PFC enabled cat6k-access
no ip address
mls qos vlan-based
mls qos trust dscp
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
Native-IOS
6500

49. Catalyst 6500 Example—Native (Cont.)
Distribution Layer—Catalyst 6000
! Trust CoS from the Layer 2 only Catalyst 4000 Access Switch
interface GigabitEthernet2/2
description trunk port to layer 2-only cat4k
no ip address
wrr-queue cos-map 2 1 3
wrr-queue cos-map 2 2 4
mls qos vlan-based
mls qos trust cos
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
! Trust CoS from the Layer 2 only 3500 Access Switch
interface GigabitEthernet3/1
description trunk port to layer 2-only 3500
Native-IOS
6500

50. Is QoS Needed in the Campus?
“Buffer management is as important as bandwidth management…”
Just Throw Bandwidth at It…NOT!

51. Auto QoS—What Is It?
One Command per Interface to Enable and Configure QoS; Modify Global and Interface Settings to Make QoS for VoIP Work
WAN
Voice Gateways
Callmanager
Unity
Voice Applications

52. Auto QoS What does it do? Campus WAN
Enforce Trust boundary at the phone
Enforce Trust boundary on access ports and Uplink/Downlink
Setup Priority Queuing where required
Modify Queue Admission criteria where required
Modify CoS to DSCP and IP Prec to DSCP maps where required
WAN
Builds QoS VoIP Modular Quality of Service Policy
Provides LLQ for VoIP Bearer
Provides Bandwidth CBWFQ for VoIP Control
Sets up Traffic Shaping per QoS DG where required
Sets up LFI (FRF.12 or MLP) where required

53. Agenda
Quality Concerns with IP Telephony, Multimedia Applications and Mission-Critical Data
General Enterprise QoS Design Considerations
Connecting the End-Points
Designing the Campus
Enabling the WAN
QoS Impact
VoIP and the Telecommuter
Questions and Answers
Summary

54. QoS in the WAN General Guidelines
The sum of all queues should be <75% of available bandwidth; LLQ should not be more than 33% of link
Use LLQ anytime VoIP over the WAN is involved
Traffic shaping is a requirement for Frame Relay/ATM environments
Use LFI techniques for all links below 768Kbps
Don’t use LFI for any video conferencing over IP applications
TX-ring sizes may require modifications
Properly provision the WAN bandwidth
Mission critical applications (Cytrix, DLSW+, etc.)
Bandwidth hog applications = less than BE traffic
Use cRTP carefully
Less than best effort and mission critical data

55. Low-Latency Queuing Logic Tree
Layer 3 Queuing Subsystem
Layer 2 Queuing Subsystem
Low Latency Queuing
Link Fragmentation and Interleave
Police
PQ Voice PQ
PQ VC TX
Ring
Interleave
VoIP-Cntrl
Packets
Out
Packets In
MC-Data
CBWFQ
Fragment
Default
WFQ
LTBE

56. Low-Latency Queuing Logic Tree
Layer 3 Queuing Subsystem
Layer 2 Queuing Subsystem
Low Latency Queuing
Link Fragmentation and Interleave
Police
PQ Voice
Prior to 12.2 the Priority Queue Was Policing All the Time for Frame Relay on 7200 and below; for ATM and Leased Lines It Was Policing Only during Periods of Congestion;
after 12.2 the PQ ONLY Polices when There Is Congestion on the Link for All Platforms PQ
PQ VC TX
Ring
Interleave
VoIP-Cntrl
Packets
Out
Packets In
MC-Data
CBWFQ
Fragment
Default
WFQ
LTBE

57. LLQ Example—WAN Router
VoIP—Queuing
Leased Lines: 12.2(5.6)
class-map VoIP-Bearer
match ip dscp EF
class-map VoIP-Control
match ip dscp AF31
class-map Video
match ip dscp AF41
class-map mc-data
match ip dscp AF21
match ip precedence 2 !
policy-map QoS-Policy
class VoIP-Bearer
priority percent 17
class Video
priority percent
class VoIP-Control
bandwidth percent 2
class mc-data
bandwidth percent 25
class class-default
random-detect dscp-based
fair-queue
interface Multilink 1
service-policy output QoS-Policy
ATM: 12.2(3)
interface ATM1/0.1 point-to-point
service-policy output QoS-Policy
VoIPovFR: 12.2(3)
map-class frame voipofr
frame cir
frame mincir 1280
frame bc 1280
frame frag 160
service-policy output QoS-Policy
*See Roles and Config Documents Located at ESE Web Site

58. Calculating VoIP Bandwidth Requirements
Voice Payload
in Bytes
Packets per
Second
Bandwidth per
Conversion
CODEC
Sampling Rate
G.711
20 msec
160 50
80 kbps
G.711
30 msec
240 33
74 kbps
G.729A
20 msec 20 50
24 kbps
G.729A
30 msec 30 33
19 kbps
A more accurate method for provisioning is to include the Layer 2 Overhead into the bandwidth calculations:
The bandwidth consumed by VoIP streams is calculated by adding the packet payload and all headers (inbits), then multiplying by the packet rate per second.
This does not take into account the effect of such tools as RTP Header-Compression
A more accurate method for provisioning VoIP is to include the layer 2 overhead, which includes: preambles, headers, flags, CRCs, and ATM cell-padding.
ATM
+ Variable L2 Bytes
(Cell Padding)
801.Q Ethernet
+ 32 L2 Bytes
MLP
+ 13 L2 Bytes
CODEC
Frame-Relay
+ 8 L2 Bytes
G.711 at 50 pps
93 kbps
86 kbps
84 kbps
106 kbps
G.711 at 33 pps
83 kbps
78 kbps
77 kbps
84 kbps
G.729A at 50 pps
37 kbps
30 kbps
28 kbps
43 kbps
G.729A at 33 pps
27 kbps
22 kbps
21 kbps
28 kbps

59. Slow Link Efficiency Tools
Fragmentation and Interleave Not Needed on Links Greater than 768 kbps
Before
Real-Time MTU
Elastic Traffic MTU
214 ms Serialization Delay
for 1500 Byte Frame at 56 kbps
After
Elastic MTU
Elastic MTU
Real-Time MTU
Elastic MTU 64
Bytes
8 ms
4 ms
2 ms
1 ms
640 Used
Serialization Delay Matrix
56 kbps
9 ms
64 kbps
128 kbps
256 kbps
512 kbps
768 kbps
128
256
512
1024
1500
16 ms
1.2 ms
18 ms
32 ms
2.6 ms
36 ms
64 ms
5 ms
72 ms
128 ms
10 ms
144 ms
187 ms
93 ms
46 ms
23 ms
15 ms
214 ms
10ms Delay Frags
Link or
VC Speed
Frag
Size
56 kbps
70 Bytes
64 kbps
80 Bytes
128 kbps
160 Bytes
256 kbps
320 Bytes
512 kbps
640 Bytes
768 kbps
1000 Bytes
1536 kbps
2000 Bytes

60. Default TX-Ring Buffer Recommended TX- Ring Buffer
TX-Ring Sizing
Misc. VoIP QoS Tools
TX-Ring is an un-prioritized FIFO buffer which holds packets just before media transmission
Used to make sure enough packets are queued in order to maximize available BW
Will add to E-2-E delay numbers because serialization delay really equals:
Serialization delay * number of packets in the TX-Ring buffer
Default TX-Ring Buffer
Sizing (Packets) 2
8192—Must Be Changed
for Low Speed Vcs
64 (Per Main T1 Interface )
PPP 6
MLPPP
ATM
Frame Relay
Media
Recommended TX- Ring Buffer
Sizing (Packets) 3
128 kbps
192 kbps
256 kbps
512 kbps
768 kbps
Link Speed/ CIR/PVC

61. WAN QoS—Leased Lines VoIP over Leased-Line Minimum IOS 12.2(5.6)
Circuits
Queuing
Low-Latency Queuing
LFI
MLPPP—Link Speeds =< 768kb
cRTP
Supported—See Roles Doc at ESE Web Site

62. PPP QoS Example interface Multilink1
ip address
no ip mroute-cache
load-interval 30
service-policy output QoS-Policy
ppp multilink
ppp multilink fragment-delay 10
ppp multilink interleave
multilink-group 1 !
interface Serial0
bandwidth 256
no ip address
encapsulation ppp
no fair-queue

63. WAN QoS—Frame Relay VoIP over Frame Relay Minimum IOS 12.2(5.6)
Network
Queuing
Low-Latency Queuing per VC
Traffic Shaping
Frame Relay Traffic Shaping
Shape to CIR - flags and CRC overhead
Bc = CIR/100
Be = 0
MINCIR >= Sum of all configured queues
LFI
FRF.12
Link Speeds < 768kbps
Fragment Size = Max_Allowed_Jitter/(1 Byte/Line Speed in kbps)
cRTP
Supported—See Roles Document at ESE Web Site

64. Buffering which Will Cause Delay and Eventually Dropped Packets
Traffic Shaping—Why?
Misc. VoIP QoS Tools
Result:
Buffering which Will Cause Delay
and Eventually Dropped Packets
128 kbps
256 kbps T1
512 kbps
Remote Sites
Frame Relay, ATM
768 kbps T1
Central Site
Central to remote site speed mismatch
To avoid remote to central site over-subscription
To prohibit bursting above committed rate
What are you guaranteed above your committed rate?

65. Buffering which Will Cause Delay and Eventually Dropped Packets
Traffic Shaping—Why?
Misc. VoIP QoS Tools
Result:
Buffering which Will Cause Delay
and Eventually Dropped Packets
128 kbps
What about Adaptive Shaping? ESE Did Some Testing; Net-Net the Buffers in the Frame Switch Must Be Tuned Extremely Small to Achieve Timely Notification of Frame Network Congestion; EDCS
256 kbps T1
512 kbps
Remote Sites
Frame Relay, ATM
768 kbps T1
Central Site
Central to remote site speed mismatch
To avoid remote to central site over-subscription
To prohibit bursting above committed rate
What are you guaranteed above your committed rate?

66. Frame Relay Traffic Shaping (FRTS) OperationBc
7000 Bits
Interval =
125ms Interval =
CIR
56000 bps
Bits 7k
14k
21k
28k
35k
42k
49k
56k
Important: Flags and CRC Are Not Included in Shaper Calculations
Line Rate T1
4.5ms
0ms
125
250
375
500
625
750
875
1000
Time—1 Second
When 7000bits (Bc) Transmitted Credits Are Exhausted No More Packets Are Sent in that Interval; This Can Happen at the 4.5ms Point of the Interval; This Could Add Milliseconds Delay in between Packets

67. Frame Relay QoS Example
interface Serial1
no ip address
encapsulation frame-relay
load-interval 30
frame-relay traffic-shaping !
interface Serial1.71 point-to-point
bandwidth 256
ip address
frame-relay interface-dlci 71
class VoIP
map-class frame-relay VoIP
frame-relay cir
frame-relay bc 2509
frame-relay be 0
frame-relay mincir
no frame-relay adaptive-shaping
service-policy output QoS-Policy
frame-relay fragment 320

68. Frame Relay QoS Example
interface Serial1
no ip address
encapsulation frame-relay
load-interval 30
frame-relay traffic-shaping !
interface Serial1.71 point-to-point
bandwidth 256
ip address
frame-relay interface-dlci 71
class VoIP
map-class frame-relay VoIP
frame-relay cir
frame-relay bc 2509
frame-relay be 0
frame-relay mincir
no frame-relay adaptive-shaping
service-policy output QoS-Policy
frame-relay fragment 320
Frame Format
Flag 1 Byte
Header 2 Bytes
CRC 2 Bytes
Flag 1 Byte
Data Variable
Allow for Flags and CRC
95% of of CIR
Shape to CIR * Frame_Sz/[Frame_Sz + (Flags+CRC)]
256000*320 / (320+4) =

69. Frame Relay QoS Example
Flag 1 Byte
Header 2 Bytes
Data Variable
CRC 2 Bytes
Frame Format
interface Serial1
no ip address
encapsulation frame-relay
load-interval 30
frame-relay traffic-shaping !
interface Serial1.71 point-to-point
bandwidth 256
ip address
frame-relay interface-dlci 71
class VoIP
map-class frame-relay VoIP
frame-relay cir
frame-relay bc 2509
frame-relay be 0
frame-relay mincir
no frame-relay adaptive-shaping
service-policy output QoS-Policy
frame-relay fragment 320
Traffic Shaping Do the Math…
Link
Speed
CIR by
the Formula
99%
98%
97%
96%
95%
94%
56 kbps
52968
55440
54880
54320
53760
52640
52080
64 kbps
60952
63360
62720
62080
61440
60160
59520
128 kbps
124872
126720
125440
124160
122880
120320
119040
Allow for Flags and CRC
95% of of CIR
Shape to CIR * Frame_Sz/[Frame_Sz + (Flags+CRC)]
256000*320 / (320+4) =
256 kbps
252832
253440
250880
248320
245760
240640
238080
512 kbps
508816
506880
501760
496640
491520
481280
476160
768 kbps
764936
760320
752640
744960
737280
721920
714240
Formula = (Bandwidth X Fragment Size) ÷ (Fragment Size + 4 Bytes)

70. WAN QoS—ATM to Frame Relay
VoIP over Hybrid Networks 12.2(3)
ATM
Network
Frame Relay
Network
FRF.8
Queuing
Low-Latency Queuing per VC
Generic Traffic Shaping
Frame-Relay Traffic Shaping
Central 7200 ATM Configuration
ip cef !
interface ATM2/0
no ip address
no ip mroute-cache
no shutdown
atm pvc ilmi
no atm ilmi-keepalive
interface ATM2/0.37 point-to-point
pvc cisco37 0/37
tx-ring-limit 7
abr
protocol ppp Virtual-Template2
interface Virtual-Template2
bandwidth 254
ip address
service-policy output QoS-Policy
ppp authentication chap
ppp chap hostname HQ_7200
ppp chap password F1C2243
ppp multilink
ppp multilink fragment-delay 10
ppp multilink interleave
Remote 3600 Frame-Relay Configuration
interface Serial6/0
description T1 to Frame Relay switch
encapsulation frame-relay
load-interval 30
no arp frame-relay
frame-relay traffic-shaping
interface Serial6/0.73 point-to-point
description 3640
frame-relay interface-dlci 73 ppp Virtual-Template2
class VoIP-256kbs
ip address
ppp chap hostname R72HQ
Traffic Shaping
Shape to Low VC
Set MLPPP fragment
To fit in ATM Cells
Shape to CIR—Flags and CRC Overhead
Bc = CIR/100
Be = 0
MINCIR >= Sum of All Configured Queues
LFI
MLPPP over ATM and Frame-Relay in 12.2(3)
cRTP
See Roles Doc on ESE Web Site

71. ATM to Frame Relay Interworking QoS Example
Remote Frame-Relay Configuration
interface Serial6/0
description T1 to Frame Relay switch
no ip address
encapsulation frame-relay
load-interval 30
no arp frame-relay
frame-relay traffic-shaping !
interface Serial6/0.73 point-to-point
description 3640
frame-relay interface-dlci 73 ppp Virtual-Template2
class VoIP-256kbs
interface Virtual-Template2
bandwidth 254
ip address
service-policy output QoS-Policy
ppp authentication chap
ppp chap hostname R72HQ
ppp chap password F1C2243
ppp multilink
ppp multilink fragment-delay 10
ppp multilink interleave
Central ATM Configuration
interface ATM2/0
no ip address
no ip mroute-cache
no shutdown
atm pvc ilmi
no atm ilmi-keepalive !
interface ATM2/0.37 point-to-point
pvc cisco37 0/37
tx-ring-limit 3
abr
protocol ppp Virtual-Template2
interface Virtual-Template2
bandwidth 254
ip address
service-policy output QoS-Policy
ppp authentication chap
ppp chap hostname HQ_7200
ppp chap password F1C2243
ppp multilink
ppp multilink fragment-delay 10
ppp multilink interleave

72. WAN QoS—ATM VoIP over ATM Minimum 12.2(3) Queuing
Network
Queuing
Low-Latency Queuing per VC
interface ATM2/0
no ip address
no ip mroute-cache
no shutdown
atm pvc ilmi
no atm ilmi-keepalive !
interface ATM2/0.37 point-to-point
pvc cisco37 0/37
tx-ring-limit 7
abr
protocol ppp Virtual-Template2
interface Virtual-Template2
bandwidth 256
ip address
service-policy output QoS-Policy
ppp authentication chap
ppp chap hostname HQ_7200
ppp chap password F1C2243
ppp multilink
ppp multilink fragment-delay 10
ppp multilink interleave
Traffic Shaping
Generic Traffic Shaping
Shape to MCR/SCR, Based on Service Class
LFI
MLPPP over ATM in 12.2(3)
cRTP
12.2(4)XV2—See Roles Doc ESE Web Site

73. PPPoATM MLPPP ATM Cell Optimization
PVC
Speed
Frag Size (Cells)
PPP Multi-Link Fragment-Delay
Bandwidth
Real Delay
56 kbps 2
12 msec
57 kbps
13.7 msec
64 kbps 2
10 msec
68 kbps
12.0 msec
128 kbps 4
11 msec
132 kbps
12.0 msec
192 kbps 6
11 msec
202 kbps
12.0 msec
256 kbps 7
10 msec
260 kbps
10.5 msec
320 kbps 9
10 msec
337 kbps
10.8 msec
384 kbps 11
10 msec
414 kbps
11.0 msec
448 kbps 12
10 msec
452 kbps
10.3 msec
512 kbps 14
10 msec
529 kbps
10.5 msec
576 kbps 16
10 msec
606 kbps
10.7 msec
640 kbps 17
10 msec
644 kbps
10.2 msec
704 kbps 19
10 msec
721 kbps
10.4 msec
768 kbps 21
10 msec
798 kbps
10.5 msec
Modify delay and bandwidth to arrive at fragment that is multiple of 48 bytes and still gives 10ms of serialization delay

74. ATM QoS Example interface ATM2/0 no ip address no ip mroute-cache
atm pvc ilmi
no atm ilmi-keepalive !
interface ATM2/0.37 point-to-point
pvc cisco37 0/37
tx-ring-limit 3
vbr-nrt
protocol ppp Virtual-Template2
interface Virtual-Template2
bandwidth 132
ip address
service-policy output QoS-Policy
ppp authentication chap
ppp chap hostname HQ_7200
ppp chap password F1C2243
ppp multilink
ppp multilink fragment-delay 11
ppp multilink interleave
Dual VC – get a config example from Scott Vandehouten

75. QoS in the Branch Office
If any VoIP over the WAN is part of the design, advanced QoS tools are a requirement; specifically, LLQ and LFI
Branch router will typically be 1700, 2600, 3600, 3700.
L3 to L2 classification for L2 QoS
All of these support VoIP gateway interfaces: Classify VoIP traffic
Catalyst scheduling capabilities depends on hardware:
Catalyst 2950, 3550, or 3524-XL
Catalyst 4000
Catalyst 6500
NBAR to classify LTBE traffic
Mission critical applications

76. Branch Office Design 802.1Q Trunking Native VLAN=70 Aux VLAN=170
interface FastEthernet1/0
description Catalyst 4000 Branch Office Switch
no ip address
ip route cache policy
no ip mroute-cache
load-interval 30
speed 100
full-duplex !
interface FastEthernet1/0.70
description native subnet data
encapsulation dot1Q 70
ip address
service-policy output output-L3-to-L2
interface FastEthernet1/0.170
description native subnet voice
encapsulation dot1Q 170
ip address
cat4k> (enable) set vlan 70 name data70
cat4k> (enable) set vlan 170 name voice170
cat4k> (enable) set vlan 70 2/1-48
cat4k> (enable) set port host 2/1-48
cat4k> (enable) set port auxiliaryvlan 2/
cat4k> (enable) set port speed 2/1-49 auto
cat4k> (enable) set trunk 2/49 on dot1q

77. Layer 3 to Layer 2 Classification Mapping at the Branch
Requires the mod-cli Commands Available in IOS 12.1(5)T*
class-map L3-to-L2-VoIP-RTP
match ip dscp EF
class-map L3-to-L2-Video-Conf
match ip dscp AF41
class-map L3-to-L2-VoIP-Control
match ip dscp AF31 !
policy-map output-L3-to-L2
class L3-to-L2-VoIP-RTP
set cos 5
class L3-to-L2-Video-Conf
set cos 4
class L3-to-L2-VoIP-Control
set cos 3
interface e0/0
service-policy output output-L3-to-L2
WAN

78. NBAR to Identify Applications
Leased Line, Frame Relay,
ATM Network
Peer to peer applications like Napster, KaZaa, Morpheus, Grokster
Citrix and other applications that are not easy to profile/recognize—dynamic/changing ports
PDLM definitions available at:
Include definition of PDLM

79. NBAR to Classify P2P Apps and Assign Less than Best Effort Treatment
Download the latest PDLMs and copy to flash:
Activate PDLM into RAM: ip nbar pdlm flash:gnutella.pdlm
Use MQC “match protocol” statements to classify the traffic
class-map match-any P2P
match protocol gnutella
match protocol fasttrack (identifies KaZaa, Morphius and Groekster)
match protocol napster (napster.pdlm already embedded into IOS 12.2)
WRED DSCP-based to cause drops from this traffic first
policy-map P2P
class P2P
set dscp 2
Alternative is to place in separate bandwidth based queue with very small bandwidth guarantee
policy-map QoS-Policy
class class-default
fair-queue
random-detect dscp-based
policy-map P2P-CBWFQ-MIN
class P2P
bandwidth percent 1

80. Config Example – NBAR for <BE traffic
ip nbar pdlm flash:gnutella.pdlm
ip nbar pdlm flash:fasttrack.pdlm !
ip cef
class-map match-all peer-2-peer
match protocol napster
match protocol napster non-std
match protocol gnutella
match protocol fasttrack
policy-map peer-2-peer
class peer-2-peer
set ip dscp 2
interface FastEthernet0/0
ip address
speed 100
full-duplex
service-policy input peer-2-peer
class-map match-all <BE
match ip dscp 2 !
policy-map <BE
class <BE
bandwidth percent 2
class class-default
fair-queue
random-detect dscp-based
interface Serial0/0
ip address
service-policy output <BE

81. WAN QoS Summary Classification Scheduling Provisioning
Lot’s of tools—LLQ/CBWFQ, FRF.12, MLPPP, WRED, etc.
More than just VoIP and video
Mission-critical applications = bandwidth classes
Bandwidth hogs = <BE treatment

82. Agenda
Quality Concerns with IP Telephony, Multimedia Applications and Mission-Critical Data
General Enterprise QoS Design Considerations
Connecting the End-Points
Designing the Campus
Enabling the WAN
QoS Impact
VoIP and the Telecommuter
Questions and Answers
Summary

83. The Solution Test Bed— What We Tested
Leased Lines
Frame Relay
ATM to Frame
Internetworking
125 Remote Sites

84. Traffic Profile—QoS without cRTP1%
TN3270 (TOS2) 10%
FTP 15%
DNS 4%
Standard HTTP 10%
Mission-Critical HTTP (TOS2) 10%
RTP 45%
Call Setup (TOS3) 5%

85. Details on the ESE Page Get the details at:
Performance documents (WAN Agg and branch routers)
Roles document
Config quick reference

86. Adding QoS Features—Loss
Impact of QoS on RTP (voice) streams (ToS 5)
Lost data (RTP streams) from campus to branch drops from a range of 0.4—36% to 0% loss (all platforms)
% Loss (Before)
% Loss (After)
Platform
PVC Speed
7500
128 kbps
0.40
0.00
256 kbps
2.20
00.0
768 kbps
13.00
00.0
1536 kbps
17.50
00.0
7200
128 kbps
1.40
00.0
256 kbps
2.30
0.00
768 kbps
34.50
0.00
1536 kbps
36.58
0.00
3660
128 kbps
1.38
0.00
256 kbps
2.26
0.00
768 kbps
11.79
0.00
1536kbps
12.35
0.00

87. Adding QoS Features—Delay
RTP latency from campus to branch also improves
Latency msec (Before)
Latency msec (After)
Platform
PVC Speed
7500
128 kbps
22.60
256 kbps
21.80
768 kbps
621.00
22.80
1536 kbps
462.00
17.50
7200
128 kbps
24.21
256 kbps
23.82
768 kbps
347.25
22.04
1536 kbps
182.54
23.63
3660
128 kbps
24.28
256 kbps
22.44
768 kbps
482.86
22.15
1536kbps
258.74
22.08
Target for Latency Is < 50 msec

88. Adding QoS Features— Delay Variation
Jitter (RTP streams) from campus to branch also shows a noticeable improvement
Jitter msec (Before)
Jitter msec (After)
Platform
PVC Speed
7500
128 kbps
22.40
2.45
256 kbps
19.30
2.70
768 kbps
14.40
3.93
1536 kbps
10.00
3.70
7200
128 kbps
21.90
2.55
256 kbps
19.50
2.67
768 kbps
17.10
3.71
1536 kbps
11.70
3.30
3660
128 kbps
22.29
2.47
256 kbps
19.30
2.79
768 kbps
12.12
3.72
1536kbps
7.51
3.44
Target for Jitter Is < 5 msec

89. CPU Impact of Basic Voice QoS Features on 7500/VIP4-80
LLQ/LFI is part of the reason for the additional CPU load, in that PPS actually goes up, as the smaller (RTP) packets are prioritized:

90. Branch Router QoS Performance Tests
1751—Frame Relay and leased line—12.2(7.5)T
2651—Frame Relay, leased line and ATM—12.2(7.6)
3640—Frame Relay, leased line and ATM—12.2(7.6)
3725—Frame Relay, leased line and ATM (DS3)—12.2(7.6)T1
Pass/fail determined by RTP loss, delay and jitter (drawn from Chariot), and by router proc cpu
Number of Calls
Line Speed
128k 2
256k 4
768k 12
2.048M 28
4.5 M 80

91. 3725 CPU Utilization QoS + cRTP
3725 CPU by WAN Media Type (QoS and cRTP Enabled
x CPU (One Minute Avg.)
Link Speed

92. 3640 CPU Utilization QoS + cRTP
Frame Relay
QoS Impact on CPU 3640
CPU Utilization
PVC Bandwidth

93. Branch Device Summary 1751—Nice low-bandwidth branch router
3640—Problems with higher-bandwidths
3725—CPU to spare for what we tested;
Results on the ESE QoS page: QOS Performance Guide for WAN Branch Platforms

94. Agenda
Quality Concerns with IP Telephony, Multimedia Applications and Mission-Critical Data
General Enterprise QoS Design Considerations
Connecting the End-Points
Designing the Campus
Enabling the WAN
QoS Impact
VoIP and the Telecommuter
Questions and Answers
Summary

95. Crypto VPN Applications
Enterprise Branch VPN
VPN
Telecommuter VPN
VPN
VPN Client

96. VoIP + Crypto: Where Are We?
Some customers are already doing this
V3PN launch underway
Site to site, QoS enabled, and SOHO DG’s from your SE
Project in the works—Queuing mechanism for the crypto engine (LLQ before crypto)
Beginning to work w/ SPs on how to provide this service; CPN certification underway with AVVID friendly SLA’s:

97. Provisioning: VoIP Bandwidth Calculations with IPSec
VoIP Packet
Voice Payload
RTP Header
UDP Header
IPSec and GRE Headers
Link
Header
IP Header
X Bytes
12 Bytes
8 Bytes
20 Bytes
76/80 Bytes
(Variable)
X Bytes
VoIP with IPSec MLPPP over ATM
ATM Cells
53b Cells 48b Payload
IP UDP RTP
and IPSec
CODEC
PPP
G.711 at 50 pps
112 kbps
kbps
kbps
G.729A at 50 pps
54.4 kbps
56.8 kbps
63.6 kbps

98. Traffic Shaping Traffic shaping to uplink speed
DSL
Backbone
3d-Party
DSL Modem
806/1710
To Head End
128k Uplink
10/100m Ethernet
Shaped
Traffic shaping to uplink speed
Avoid uplink congestion
Ensure that QoS honored

99. Classification and Scheduling, LFI, and Traffic Shaping
Single-Box
827
DSL
Backbone
DSL
To Head End
Two-Box
PIX 501
Variation:
VPN 3002 Can Be Used in Place of PIX 501 if Firewall Not Required
Third-Party
Modem
806/1710
3d-Party
DSL Modem
Single-Box
9x5
Cable
Backbone
Cable
Two-Box
To Head End
PIX 501
Variations:
VPN 3002 Can Be Used in Place of PIX 501 if Firewall Not Required
Third-Party
Modem
806/1710
3d-Party
Cable Modem
ISDN,
Wireless
Etc.
Others
To Head End
Others
PIX 501
80x

100. DSL Options Classification and scheduling LLQ/CBWFQ
Single-Box
827
DSL
Backbone
To Head End
Two-Box
PIX 501
Third-Party Modem
3d-Party
DSL Modem
806/1710
Classification and scheduling LLQ/CBWFQ
Link fragmentation and Interleave (MLPPP)
PPPoATM vs PPPoEthernet
PPPoATM fragment size to ATM Cell considerations

101. Config Example—PPPoATM (827)
class-map match-all voice
match ip dscp EF
class-map match-all signaling
match ip dscp AF31 !
policy-map telework
class voice
priority 64
class signaling
bandwidth 8
class class-default
fair-queue
interface ATM0
no ip address
pvc 1/100
vbr-rt
tx-ring-limit 3
encapsulation aal5mux ppp dialer
dialer pool-member 1
interface Dialer0
bandwidth 132
ip address negotiated
ip nat outside
encapsulation ppp
no ip mroute-cache
load-interval 30
dialer pool 1
dialer-group 1
service-policy output telework
no cdp enable
ppp authentication chap callin
ppp chap hostname 827a
ppp chap password 7 104D000A0618
ppp multilink
ppp multilink fragment-delay 11
ppp multilink interleave

102. Agenda
Quality Concerns with IP Telephony, Multimedia Applications and Mission-Critical Data
General Enterprise QoS Design Considerations
Connecting the End-Points
Designing the Campus
Enabling the WAN
QoS Impact
VoIP and the Telecommuter
Questions and Answers
Summary

103. What Questions Do You Have?

104. Summary Classification (trust boundary), scheduling, provisioning
Mission-critical data, voice, video
QoS in the LAN—not just bandwidth—transmit buffer management/congestion avoidance
Lots of tools—LLQ/CBWFQ, PQ, WRR, WRED, LFI—FRF.12, MLPPP, traffic shaping
QoS is an end-to-end proposition; look Quality of Service Policy Manager (QPM) in World of Solutions and keep an eye out for Auto QoS…