Wireless QoS Training
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Transcript of Wireless QoS Training
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2006 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 1
Cisco UnifiedWireless Network
WLAN QoS
Syed Ali (sali)Network Consulting Engineer
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WLAN QoS
Overall Concept
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CUWN WLAN QoS Goals
Primary Goal
Judicious usage of RF bandwidth. RF bandwidth andresponsiveness is finite and needs to be applied wisely to
serve business needs.
Secondary Goal
Manage LWAPP/CAPWAP tunnel traffic consistently with end-to-end QoS model in balance with wired QoS policies.
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QoS on the WLAN
Shared access to bandwidth
Packets marked with 802.1p and/or DSCP
QoS is currently available to downstream traffic from the AP, but
few devices (WMM) can provide upstream QoS toward the AP Can provide only limited admission control
Unlike wired networks with dedicated bandwidth, WLAN networksmust consider traffic direction when they implement QoS. Traffic isconsidered either upstream or downstream from the point of view
of the AP
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CUWN WLAN QoS translation points
UPSTREAM
Radio upstream QoS:Traffic leaving the WLAN clients and traveling tothe AP. WMM provides upstream QoS for WLANclients supporting WMM (UP marking). Clientupstream QoS depends on client implementation.
Network upstreamTraffic leaving the AP, traveling to the WLC.Tunnel encapsulation. AP classifies traffic from theAP to the upstream network according to the trafficclassification rules of the AP.
WLC tunnel decapsulation andtransmission to wired network
DOWNSTREAM
Wired Network to WLC
Radio downstream QoS:Traffic leaving the AP and traveling to the
WLAN clients. AP tunnel de-capsulation andtransmission/scheduling to WLAN client (WMMclient UP marking).
Network downstream:Traffic leaving the WLC traveling to the AP.Tunnel encapsulation. QoS can be applied atthis point to prioritize and rate-limit traffic to AP.
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Wi-Fi Multimedia(WMM)
WLAN Quality of Service
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802.11 MAC Modes
Coordination functions control access to the wirelessmedium. Two types of services provided are:
Contention based service - provided by DCF
(Distributed Coordination Function)Basis of CSMA/CA, uses random backoff, RTS/CTS
Contention free service - provided by PCF (PointCoordination Function)
Used only in infrastructure networks
Point coordinators residing in access points used
Allows stations to transmit frames after a shorter interval togain priority over contention based services
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Distributed Coordination Function (DCF)
DCF used in 802.11 networks to manage access to the RF medium
Data frames in 802.11 are sent using DCF (two main components):
Interframe spaces (SIFS, PIFS, and DIFS)
Random backoff (contention window)
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DCF CSMA/CA Algorithm
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DCF, CWmin, CWmax
DCF uses a contention window (CW) binary exponential backoff tocontrol the size of the random backoff defined by the parameters:
aCWmin
aCWmax
Retries (TTL)
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Why QOS or 802.11e?
Basic DCF is not QoS friendly
Need to contend for every MSDU
Contention treats all traffic similar.
That is a voice frame contends with the data frame using thesame parameters
No concept of priority to important traffic even insidethe STA.
Once the sequence number is allotted, that MSDU must betransmitted before attempting the next MSDU
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Wi-Fi Multimedia
Wi-Fi Multimedia (WMM) is a Wi-Fi Alliance certification of supportfor a set of features in IEEE 802.11e
802.11e introduces additional MAC modes, e.g. the EnhancedDistributed Channel Access (EDCA)
WMM is the implementation of the EDCA component of 802.11e.
Different interframe spacing and CWmin and CwMax values areapplied per traffic classification
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EDCF: CWmin and CWmax
CWmin and CWmax a manipulated to give different QoS
DIFS Contention Window
Slot time
Busy Medium Backoff Window
Defer Access Decrement backoff as long as the
medium is idle
Next Frame(t)
0
CWmin[6]
Voice random backoff range
Video random backoff range
Best effort random backoff range
CWmin[7]
CWmin[0]
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EDCF: CWmin and CWmax
CWmin and CWmax a manipulated to give different QoS
This is a statistical process
Station X
Voice 1
Best Effort 1
Voice 2
Best Effort 2
Frame
Defer
Defer
Defer
DIFS DIFS
Frame
DIFS
Backoff time
Backoff time remaining
Defer
Defer
Defer
Frame
Frame
Defer
Defer
Voice 3 Defer Defer Defer
DIFS
Frame
Defer Defer
Defer
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WMM Client, eg. VoWLAN Client
VoIP client marks traffic with DSCP Value (EF)
OS Maps DSCP to CoS (6)
WLAN Client Maps CoS to WMM AC (VO)
WMM AC VO gives traffic highest priority
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WMM Framing
WMM uses 802.1D priority classification
This is commonly referred to as 802.1p marking
Frame
ControlDur A 1 A 2 A 3
Seq
ControlA 4
QoS
ControlBody FCS
0ack
policyEOSP 0 UP
15-7 6-5 4 3 2-0
802.1D Priority
End of Service Period
0001
Acknowledge
Do not Acknowledge
2 2 6 6 6 2 0 or 6 0 or 2 n 4
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WMM Access Categories
Queuing performed on a WMM client or AP
WMM Access Categories are 4 internal queues for the WLAN Radio
Called, bronze, silver, gold, and platinum on the controller
These form a distributed queue for the entire RF channel
Note: These are queues for Unicast frames only, IP Multicast typicallyscheduled in Best Effort queue
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WLC QoS Profiles
WLC QoS Profiles match WMM Access Categories
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WMM Classification
Uses 802.1p Classification
Priority 802.1 Priority
(User Priority)
802.1p Designation Access
Category
WMM
Designation
Highest 1 BK, Background AC_BK Background
2 -Spare
Lowest 0 BE, Best Effort
3 EE, Excellent Effort AC_BE Best-Effort
4 CL, Control Load
5 VI Video < 100ms AC_VI Video
6 VI Voice < 10ms AC_VO Voice
7 NC, Network Control
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IEEE 802.11e WMM Access Categories
Access Category Description 802.1d Tags
WMM Voice Priority
AC_VO
Highest Priority (MultipleCalls, Low Latency and Toll
Voice Quality)7, 6
WMM Video Priority
AC_VIVideo 5, 4
WMM Best EffortPriority
AC_BE
Legacy Devices orApplications That Lack QoS
Capabilities0, 3
WMM BackgroundPriority
AC_BK
Low Priority Traffic (FileTransfers, Printing)
2, 1
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Packet Markings
Implementation
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WMM, DSCP and 802.1p Relationship
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Mapping of QoS Packet Markings
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The Translation Table
Cisco AVVID 802.1p
UP-Based Traffic Type
Cisco AVVID
IP DSCP
Cisco AVVID
802.1p UP
IEEE
802.11e
UP
Notes
Network Control - 7 - Reserved for network
control onlyInter-Network Control 48 6 7 (AC_VO) CAPWAP control
Voice 46 (EF) 5 6 (AC_VO) Controller: PlatinumQoS Profile
Video 34 (AF41) 4 5 (AC_VI) Controller: Gold QoSprofile
Voice Control 26 (AF31) 3 4 (AC_VI) -
Best Effort 0 (BE) 0 3 (AC_BE)
0 (AC_BE)
Controller: Silver QoS
Profile
Background (Cisco AVVID
Gold)
18 (AF21) 2 2 (AC_BK) -
Background (Cisco AVVID
Silver)
10 (AF11) 1 1 (AC_BK) Controller: Bronze QoSprofile.
The AP and WLC maintain a DSCP to CoS translation table
Both IEEE CoS and Cisco QoS Baseline CoS
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QoS Baseline IEEE 802.1 UP-Based
Traffic TypeWireless
Controller .1P
Setting
(802.11e)
LWAPP DSCP AVVID IEEE802.1p UP
Network control - 7
Inter-network control (LWAPP control,
IEEE 802.11 management)
7 48 (CS6) 6
Voice (Platinum) 6 46 (EF) 5
Video (Gold) 5 34 (AF41) 4
4 26 (AF31)
Voice Control (Silver) 3 18 (AF21) 3
2 10 (AF11) 2
Background (Bronze) 1 2 2
0 0 2
QoS Translation Table: Upstream
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QoS Translation Table: Downstream
QoS Baseline IEEE 802.1 UP-
Based Traffic Type
Max
LWAPP
DSCP
AVVID IEEE
802.1p UP
Wireless
Controller .1P
Setting
(802.11e)
Network control - 7
Inter-network control (LWAPPcontrol, IEEE 802.11
management)
56 (CS7) 6 7
Voice (Platinum) 48 (CS6) 5 6
Video (Gold) 46 (EF) 4 5
32 (CS4) 4
Voice Control (Silver) 24 (CS3) 3 3
16 (CS2) 2 2
Background (Bronze) 8 (CS1) 2 1
0 2 0
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Some Basic Concepts
Each WLAN has a default priority (0-7) that has a bearing on the 802.1p,802.11e/WMM and DSCP markings on the packets
Default priority is assigned by choosing a WLAN to be Platinum, Gold, Silveror Bronze
A Ceiling function will make sure that the 802.11e priority or the equivalentDSCP of a packet on a WLAN is less than or equal to the default priority of aWLAN
A Policing function will make sure that 802.11e UP of a packet isdowngraded to zero if the client does not use TSPEC if Admission Control isMandatory.
6 translation MAPs are used to derive markings as applicable all MAPs areAVVID complaint:
DSCP_to_11e_map (on AP outgoing traffic)11e_to_DSCP_map (on AP incoming traffic)
11e_to_AC_map (on AP outgoing traffic, WMM Compliant)
DSCP_to_1p_map (on controller for incoming traffic)
.1p_to_AVVID_UP and vice-versa (on AP, used only in REAP LocalSwitching/Standalone)
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802.1p DSCP | PayloadDSCP | Payload802.11e
LWAPP Encapsulated
DSCP | Payload802.11eDSCP
802.1p DSCP | PayloadDSCP | Payload802.11e
LWAPP Encapsulated
DSCP | Payload802.11eDSCP802.1p
LWAPP Tunnel
21
34
WLAN QoS mapping
Upper value of mapped DSCP constrained automatically based on WLAN QoS Profile
Upper value of mapped 802.1p value constrained by Wired QoS Protocol setting
Upper value of mapped 802.1p value constrained by Wired QoS Protocol settingDSCP directly mapped from arriving packet DSCP
Upper value of mapped 802.11e UP constrained automatically by WLAN QoS profile
1
2
3
4
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Cisco Implementation
WMM Specification based on IEEE 802.1p UP
Cisco Model based on DSCP and AVVID
In the Cisco deployment model, traffic destined to APs connected to accessports lack a .1p tag
Utilize the Layer 3 DSCP information in order to provide QoS in the absence
of Layer 2 QoS information Layer 3 DSCP is used by APs to ensure packets receive correct over the
air prioritization from the AP to the wireless client.
To maintain the QoS classification across the LWAPP tunnel, the QoSsettings of the encapsulated data packet must be appropriately mappedto the Layer 2 (802.1p) and Layer 3 (IP DSCP) fields of the outer tunnelpacket.
802.1p UP
Outer
IP DSCP
Outer
LWAPP
encapsulatedIncoming
802.1p UP
IP DSCP
Inner.
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AP Controller Traffic On the AP
AP will not send tagged packets as this causes a problem withCisco switches. Hence AP will not copy 802.11e UP incoming to802.1p UP (outer)
On the ControllerGenerate the.1p for the wired side, using the incoming DSCP(outer)
The outer .1p value from AP does not exist, because the APwill be sending NULL VLAN ID frames
IP DSCP
Outer
LWAPP
encapsulated Incoming
802.11e UP
IP DSCP
Inner.
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Reference Diagram
Best Effort Data
Non-WMMClient
WMM
Client
A
BC
E
FUntagged Interface
.1q Tagged Interface
WMM Traffic
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Packet Formats
Link A Untagged Ethernet framesin and out of the controller
Link B tagged 802.1q frames inand out of the controller
Link C
Packets from AP to Controllerare untagged Layer 3 LWAPPpackets
Packets from Controller to APare 802.1q tagged Layer 3LWAPP packets
DataD
S
C
P
DataD
S
C
P
1p
LWAPP DataD
S
C
P
Dot
11
D
S
C
P
1pLWAPP Data
D
S
C
P
Dot
11
D
S
C
P
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Link F Non-WMM Client
AC = VO
AC = VI
AC = BE
AC = BK
DataD
S
C
P
Dot
11
Packets from AP to Client
A UP to AC look up placesthem in the righttransmission queue
Over the air the packetgoes in regular 802.11 Dataformat
Packets from Client to AP
Over the air the packetcomes in as a regular802.11 Data packet
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Link E WMM Client
Packets from AP to Client
A UP to AC look up placesthem in the right transmissionqueue
Over the air the packet goes inQoS Data format with WMM UP
Packets from Client to AP
Over the air the packet comesin as a regular 802.11 QoSData packet
AC = VO
AC = VI
AC = BE
AC = BK
WMM
QoS DataD
S
C
P
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Packet from Link A/B to Link F:Non-WMM Client
a. Put LWAPP Encap
b. Copy inner DSCP to outer DSCP
c. Use DSCP_to_1p_Map to create a .1q
Header
Put on Link C
a. Decap LWAPP header
b. 11e priority = Default
priority of WLAN on which
this non- WMM Client is
associated
c. Use 11e UP to insert the
packet into the right queue
using WMM 11e_to_AC
mappings.
Put 802.11
Data packets
on Link F
Controller
Access Point
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Packet from Link A/B to Link E:WMM Client
a. Put LWAPP Encap
b. Copy inner DSCP to outer DSCP
c. Use DSCP_to_1p_Map to create a .1q
header
Put on Link C
a. Decap LWAPP header
b. Derive 11e UP using
DSCP_to_11e_Map.
c. Apply Ceiling: Check
against WLAN default
priority, modify 11e UP if
higher than def priority
d. Apply Access Policing: If
ACM bit is turned on Apply
policing to derive new 11e
UP. UP = 0 if tspec not used.
UP remains the same if
tspec is used for the STA.
e. Use 11e UP to insert the
packet into the right queue using WMM 11e to AC
mappings.
Put 802.11 QoS
Data packets on
Link E
Controller
Access Point
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Controller to AP Traffic
LWAPP Tunnels SiSiSiSiSiSi
WLAN Controller
AP
Ethernet Switch
LWAPP Encapsulated
DSCP PayloadDSCP
802.1p DSCP Payload802.1p
11
UP (802.1p / 802.11e) IP DSCP
Copy the 802.1p value from the incoming packet.
Police the value to ensure it does not exceed the
maximum value allowed for the WLAN QoS policy
assigned to that client.
Copy the DSCP value from the
incoming packet.
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AP to Non-WMM Client Traffic
LWAPP Tunnels SiSiSiSiSiSi
WLAN Controller
AP
Ethernet Switch
LWAPP Encapsulated
802.11e DSCP Payload DSCP PayloadDSCP
802.1p DSCP Payload802.1p
22
Regular client: place packet in thedefault 802.11 Tx queue for theWLAN QoS policy assigned to thatclient
N/A (original DSCP value is preserved)
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AP to WMM Client Traffic
LWAPP Tunnels SiSiSiSiSiSi
WLAN Controller
AP
Ethernet Switch
LWAPP Encapsulated
802.11e DSCP Payload DSCP PayloadDSCP
802.1p DSCP Payload802.1p
22
WMM Client: Map the DSCP valueof the incoming LWAPP packet tothe 802.11e UP value
Place in the 802.11 Tx queueappropriate for that UP value.
N/A (original DSCP value is preserved)
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Packet from Link F to Link B:Non-WMM Client
a. 11e UP = default priority of WLAN
b. Lookup 11e_to_DSCP_Map on 11e priority
to determine outer DSCP of LWAPP header
c. Apply LWAPP header
Decap LWAPP header
Use DSCP_to_1p_Map to determine
.1p priority using outer DSCP
Prepare dot1q packet with .1p priority
Access Point
Controller
Xmit on
Link A
Xmit on Link B
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Packet from Link E to Link B:WMM Client
a. 11e UP = UP of QoS Data Packet on air
b. Apply Policing: modify UP to 0 if ACM is
Enabled and there are no tspecs for the STA
c. Apply Ceiling: modify UP to make sure that it
is less than or equal to the default WLAN
priority
d Lookup 11e_to_DSCP_Map for 11e UP
to determine outer DSCP of LWAPP header
e. Apply LWAPP header
Decap LWAPP header
Use DSCP_to_1p_Map to determine
.1p priority using outer DSCP
Prepare dot1q packet with .1p priority
Access Point
Controller
Xmit on
Link A
Xmit on Link B
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AP to Controller: Non-WMM Client Traffic
LWAPP Encapsulated
LWAPP TunnelsSiSiSiSiSiSi
WLAN Controller
AP
Ethernet Switch
802.11e DSCP Payload DSCP PayloadDSCP
33
Regular Client: use the 802.11e
UP value for the QoS policyassigned to that client; map thevalue to the DSCP value.
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AP to Controller: WMM Client Traffic
LWAPP Encapsulated
LWAPP TunnelsSiSiSiSiSiSi
WLAN Controller
AP
Ethernet Switch
802.11e DSCP Payload DSCP PayloadDSCP
33
WMM Client: Police the 802.11eUP value to ensure it does not
exceed the maximum valueallowed for the QoS policyassigned to that client; map thevalue to the DSCP value.
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Controller to Ethernet Switch Traffic
LWAPP Encapsulated
LWAPP TunnelsSiSiSiSiSiSi
WLAN Controller
AP
Ethernet Switch
802.11e DSCP Payload DSCP PayloadDSCP 802.1p DSCP Payload
44
Map the DSCP value of the original packet
to the 802.1p UP value. N/A (original DSCP value is preserved)
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Knobs
WMM allowed/required: If WMM is allowed, both WMM andnon-WMM clients can associate. If WMM is required onlyWMM clients can associate
ACM enabled: ACM should be enabled only if CAC is to beused. If ACM is enabled policing kicks-in for WMM clients
Protocol Type: None or 802.1p. If 802.1p is selected thepackets on wired tagged interfaces (such as link B) will have.1p markings
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Pivotal Points
Is 802.11 RF Transmission to/from WMM client ?- WMM client = pragmatically trust DSCP (downstream) or802.11e (upstream)
- non-WMM client = no trust, force WLAN QoS level
Is TSPEC CAC configured (aka WLC WIRELESS ->802.11a or 802.11b/g -> Voice CAC or Video CAC ?
- if enabled, WMM client required and one that signals TSPECtraffic access (ADDTS) otherwise related Access Category issent as Best Effort transmission
What is the WLAN defined QoS setting and the QoSProfile 802.1p setting ?
- these setting set the ceiling limit for various QoS translationpoints
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Pivotal Points
WLC/AP translation points tend to demote, not promote,the QoS marking
- WLAN QoS setting and QoS Profile 802.1p setting workcollective to set ceiling for QoS classification translations.
Avoid remarking the DSCP on encapsulated tunnel ifpossible.
- if must be done somewhere, then AP and WLC will still cap thetraffic based on WLAN QoS setting and also the QoS Profile802.1p setting.
- wired network remarking DSCP down will effect resultingdownstream 802.11e eDCF WMM transmission queue, althoughremarking up beyond the WLAN QoS setting and QoS Profile802.1p setting does not. Upstream remarking does not changeanything except wired network handling
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Pivotal Points
HREAP locally switched (aka, AP tagged frames todirect switchport) pragmatically the same, although trustmodel is effective 802.1p CoS marking.
- WMM client (upstream) = 802.11e WMM is translated to 802.1ptagging
- WMM client (downstream) = 802.1p tagging is translated to802.11e AC
- non-WMM client (downstream & upstream) = should betranslated to/from WLAN QoS setting
- Note, WLAN QoS Setting and QoS Profile 802.1p setting still
applies as ceiling limit for translations- Note, user vlan for HREAP local switching needs to be802.1Q/p tagged (aka not native vlan of AP) if QoS operation isdesired.
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Pivotal Points WLC should start with trust CoS & management & ap-manager
should be 802.1Q/p tagging- since WLC does not do DSCP rewrite (eg non tunnel user frames), thenstarting with mls qos trust cos facing WLC to enforce CUWN basedceiling/trust model.
- management & ap-manager interfaces should have non-0 VLANtag number.
AP tunnel frames are native/non-tagged, thus LAP-s should trustDSCP
- AP to WLC frames are native/non-tagged, thus mls qos trust dscp
- exception to this is HREAP local switching, then since enforcement ofCUWN trust model is desired use mls qos trust cos. Expectation is that
WLC is either across WAN with explicit service policy forAPs nativeframe CUWN CAPWAP/LWAPP mgmt & central-switching tunnelframes.
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WLAN QoS
WLC Configuration
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WLAN QoS Profiles
Four ProfilesPlatinum (Voice)
Gold (Video)
Silver (Best Effort)
Bronze (Background)
WLAN QoS Profiles apply forWMM and non-WMM clients
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QoS Profiles
An 802.1p tag can be applied to wired side to allow proper precedence to be applied
to traffic across the entire network infrastructure
If it is none, then there is no dot1p marking applied to frames leaving the WLC
If it is 802.1p, the 802.1p Tag value is the maximum value that the DSCP 802.1p
translation table will apply
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QoS Profile - Platinum
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TSPEC Call Admission Control (CAC)
ACM =TSPEC Admission Control Unless your client supports TSPEC
Do not enable Call Admission Control
Otherwise the AP will transmit yourclient traffic for this AC (eg AC_VO or
AC_VI) at best effort
Load-based AC = RF Channel capacityconsidered
Defaults Max RF Bandwidthrecommended setting is 40 to 60 %
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EDCA Parameters
Different EDCA Parameters are available to optimize the WLANQoS.
These are global (per-band)
Low Latency MAC adjusts retries and queue depths to moreappropriate values for voice
EDCA P t
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WMM:Configured Local Access Class ParametersBack : cw-min 4 cw-max 10 fixed-slot 7 admission-control Off txop 0
Best : cw-min 4 cw-max 10 fixed-slot 3 admission-control Off txop 0Video : cw-min 3 cw-max 4 fixed-slot 2 admission-control Off txop 0Voice : cw-min 2 cw-max 3 fixed-slot 2 admission-control Off txop 0
Spectralink Voice priority:Configured Local Access Class ParametersBack : cw-min 4 cw-max 10 fixed-slot 7 admission-control Off txop 0Best : cw-min 4 cw-max 10 fixed-slot 3 admission-control Off txop 0Video : cw-min 3 cw-max 4 fixed-slot 2 admission-control Off txop 0Voice : cw-min 2 cw-max 3 fixed-slot 2 admission-control Off txop 0
Voice Optimized:
Configured Local Access Class ParametersBack : cw-min 8 cw-max 10 fixed-slot 12 admission-control Off txop 0Best : cw-min 6 cw-max 10 fixed-slot 5 admission-control Off txop 0Video : cw-min 3 cw-max 5 fixed-slot 5 admission-control Off txop 0Voice : cw-min 2 cw-max 4 fixed-slot 2 admission-control Off txop 0SIP stats sip_udp_rx_pkt 0, sip_tcp_rx_pkt 0,
Voice and Video Optimized:Configured Local Access Class ParametersBack : cw-min 8 cw-max 10 fixed-slot 12 admission-control Off txop 0Best : cw-min 6 cw-max 10 fixed-slot 12 admission-control Off txop 0Video : cw-min 3 cw-max 5 fixed-slot 5 admission-control Off txop 0
Voice : cw-min 2 cw-max 4 fixed-slot 2 admission-control Off txop 0SIP stats sip_udp_rx_pkt 0, sip_tcp_rx_pkt 0,
show controllers dot11Radio {0|1}
EDCA Parameters
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Configurations
Voice Deployment
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Cisco Recommendations
Trust DSCP
VoIP traffic is best suited for EF (DSCP 46)
Call-Signaling originally marked AF31, Cisco
recommends migration to CS3
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Controller Adjustments
Disableaggressiveload-balancing
Controllersmust havesamemobility infofor seamless
roaming
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Voice Interface
Enable VLANtagging on thevoice interfaceand other non-
managementinterfaces
Ensure DHCPserver is
configured foreach interface
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SSID Configuration
RecommendedWPA security withTKIP plus CCKMfor authenticatedkey management
Ensure WMM isEnabled
QoS profile is setto Platinum
DHCP Address
Assignment asNOT required
Configure theRADIUS serverswhen using 802.1x
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Platinum QoS Profile
Set the 802.1ptag for thePlatinum QoSprofile to 6
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802.11a Global Parameters
Set the DTIMperiod to 2,where thephone wouldwake up every200ms with a100ms beaconperiod to checkfor incoming
packets Ensure DTPC
is enabled
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802.11b/g Global Parameters
If 802.11b clientsexist in thenetwork, then itis recommendedto enable 11mbps as the
basic rate(mandatory), set18 54 mbps asoptional(supported) and
disable the otherlower data rates
Ensure DTPC isenabled
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802.1x Timeout
If using EAP-FAST or the 802.1x authentication is traversing overa WAN, the 802.1x timeout may need to be increased on thecontroller (default = 2 seconds) in order for the client to obtain thePAC via automatic provisioning
The default timeout on the Cisco ACS server is 20 seconds, whichis the recommended value
To change the 802.1x timeout on the Airespace controller, telnet orSSH to the controller and enter the following command
(Cisco Controller) >config advanced eap request-timeout 20
(Cisco Controller) >show advanced eap
EAP-Identity-Request Timeout (seconds)........... 1
EAP-Identity-Request Max Retries...................... 20
EAP Key-Index for Dynamic WEP....................... 0
EAP-Request Timeout (seconds)........................ 20
EAP-Request Max Retries................................... 2
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ARP Caching
ARP caching can be enabled by the following command
(Cisco Controller) >config network arpunicast enable
(Cisco Controller) >show network
RF-Network Name.......................................... SJC21-VoWLAN
Web Mode....................................................... Disable
Secure Web Mode.......................................... Enable
Secure Shell (ssh).......................................... Enable
Telnet............................................................... Enable
Ethernet Multicast Mode................ ................ Disable Mode: Ucast
User Idle Timeout........................................... 300 secondsARP Idle Timeout........................................... 300 seconds
ARP Unicast Mode......................................... Enabled
Cisco AP Default Master................................ Disable
Mgmt Via Wireless Interface.......................... Enable
Mgmt Via Dynamic Interface........................... Disable
Bridge AP Zero Config.................................... Enable
Bridge Shared Secret...................................... cisco
Allow Old Bridging Aps To Authenticate...... Disable
Over The Air Provisioning of AP's................. Enable
Mobile Peer to Peer Blocking......................... Disable
Apple Talk ........................................................ Disable
AP Fallback ..................................................... Enable
Web Auth Redirect Ports ................................ 80
Fast SSID Change ........................................... Disabled
802.3 Bridging ................................................. Disable
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WMM Clients
WLAN QoS
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Client Capabilities
What to look for in a client review?
WMM Specifications
CCX(v4) Certification
Support for U-APSD, DTPC, TSPEC, CACTransmit Power/Receive Sensitivity
Antenna Gain
802.11 Security Options
E-911 call capability and location support
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CCX Benefits
Feature Benefit
CCKM Support for EAP-TypesLocally Cached Credentials
Means Faster Roams
Unscheduled Automatic Power
Save Delivery (U-APSD)
More Channel Capacity and
Better Battery Life
TSPEC-Based Call
Admission Control (CAC)
Managed Call Capacity for Roaming
and Emergency Calls
Voice MetricsBetter and More Informed
Troubleshooting
Neighbor List Reduced Client Channel Scanning
Load Balancing Calls Balanced Between APs
Dynamic Transmit PowerControl (DTPC)
Clients Learn a Powerto Transmit At
Assisted Roaming Faster Layer 2 Roams
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CCX Information on Controller
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WMM Based U-APSD
Allows synchronization ofsend/receive in oneoperation
AP has perclient buffer
Client initiatestransmission
Improved battery life
Potential to increase the
number of calls each APis capableof handling
U-APSD
NON U-APSD
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DTPC
Set the same transmit power on the AP and on thephones
The Unified Controller advertises its transmit power for
the clients to learn Prevents one-way audio
RF traffic is only being heard in one direction
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TSPEC Based CAC
Defined tothe AP:
Whatpercentage oftraffic will be
reserved fordata and voice?
Benefit: EnsuresThat the NumberOf Active Voice
Calls Do NotExceed TheConfiguredLimits
X
http://www1.us.dell.com/content/products/category.aspx/inspn?c=us&cs=04&l=en&s=bsdhttp://www1.us.dell.com/content/products/category.aspx/inspn?c=us&cs=04&l=en&s=bsdhttp://www1.us.dell.com/content/products/category.aspx/inspn?c=us&cs=04&l=en&s=bsdhttp://www1.us.dell.com/content/products/category.aspx/inspn?c=us&cs=04&l=en&s=bsd -
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CAC on the Controller
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Wired QoS
Wired Network QoS
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The Wired QoS Protocol
If it is none, then there is nodot1p marking applied to framesleaving the WLC
If it is 802.1p, the 802.1p Tag
value is the maximum value thatthe DSCP 802.1p translationtable will apply
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Wired Network QoS Recommendations
DSCP 48 (CS6) for LWAPP control (AVVID CoS 6)
DSCP 46 (EF) for VoIP Traffic (AVVID CoS 5)
DSCP 26 (AF31) for Call-Signaling (AVVID CoS 3)
Priority Queue 46 (EF), 48 (CS6) and 26 (AF31) traffic
Trust 48/46/26 and CoS=6/5/3 as applicable
Hand off 48/46/26 to the router to be handled by the
router's QoS policy.
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Access Switch Configuration
Enable QoS globally
mls qos
Trust DSCP on the Switch Port
interface FastEthernet0/1description Access Port to Cisco LWAPP AP-01
switchport access vlan 133
switchport mode access
duplex fullmls qos trust dscp
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Distribution Switch Configuration
Enable QoS globally and include cos-dscp Mapping
mls qos map cos-dscp 0 8 16 26 32 46 48 56
mls qos
Interface Configuration
interface GigabitEthernet1/0/1description Trunk Port to Cisco WLC
switchport trunk encapsulation dot1q
switchport trunk allowed vlan x,y,z (only allow the vlans that need totalk to the controller)
switchport mode trunkmls qos trust cos
channel-group 30 mode on
no shutdown
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