Submission doc.: IEEE 11-13/0221r2 Mar 2013 BroadcomSlide 1 802.11 QoS Queue Architecture and...
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Transcript of Submission doc.: IEEE 11-13/0221r2 Mar 2013 BroadcomSlide 1 802.11 QoS Queue Architecture and...
Submission
doc.: IEEE 11-13/0221r2Mar 2013
BroadcomSlide 1
802.11 QoS Queue Architecture and Possible 802.1bz Bridge Model “for P2P
Model”
Date: 2013-03-18
Name Affiliations Address Phone email Philippe Klein Broadcom Golan Building
Airport City, Israel +972 54 3134500 [email protected]
David Goodall Broadcom 24 Campbell Street Haymarket, Sydney, NSW, 2000
+61-2-8030-7452 [email protected]
Authors:
Submission
doc.: IEEE 11-13/0221r2
Broadcom
Abstract
This presentation describes
- the structure of the QoS Queuing in the 802.11 AP and non-AP STA devices,
- a possible architecture model for 802.1bz bridge.
- technical issues
Slide 2
Mar 2013
Submission
doc.: IEEE 11-13/0221r2
Broadcom
802.11 - QoS Specifications
EDCA (Enhanced Distributed Channel Access)- High-priority traffic has a higher chance of being sent than low-
priority traffic- Contention window (CW) and arbitration inter-frame space
(AIFS) determines the probability to gain the access to the medium
- CW and AIFS values are a function of the priority level.
- Transmit Opportunity (TXOP) is the bounded time interval during which the transmitter can send as many frames as possible
Wi-Fi Alliance’s WMM (Wi-Fi Multimedia) is a subset of 802.11 (EDCA, TxOP)
Slide 3
Mar 2013
Submission
doc.: IEEE 11-13/0221r2
Broadcom
802.11 Access Categories
EDCA/WMM Medium Access does not guarantee QoS QoS can be improved by Admission Control that limits admission
and bandwidth utilization per Access Category
Slide 4
Mar 2013
Submission
doc.: IEEE 11-13/0221r2
Broadcom
Access Categories (AC)
EDCA levels of priority are called access categories (ACs). ACs map directly from 802.1D-2004 user priority levels:
Slide 5
Mar 2013
802.1D-2004 802.11 (UP)Wi-Fi WMM
802.11aa-2012w/ Alternate-EDCA activated
PriorityPriority
LevelDesignation AC Designation
WMMPriority
AC Designation
lowest 1 BK AC_BK BackgroundBackground BK Background
2 - AC_BK Background
0 BE AC_BE Best EffortBest Effort BE Best Effort
3 EE AC_BE Best Effort
4 CL AC_VI VideoVideo
A_VI Video (Alternative)
5 VI AC_VI Video VI Video (Primary)
6 VO AC_VO VoiceVoice
VO Voice (Primary)
highest 7 NC AC_VO Voice A_VO Voice (Alternative)
Submission
doc.: IEEE 11-13/0221r2
Broadcom
802.11 QoS Queue Architecture
Slide 6
Mar 2013
Classification to Access Categories and Transmit queues
VO VI BE BK
VO BackoffVO AIFS, VO CW
VO TxOP
VI BackoffVI AIFS, VI CW
VI TxOP
BE BackoffBE AIFS, BE CW
BE TxOP
BK BackoffBK AIFS, BK CW
BK TxOP
Channel Access functions
(EDCA functionswith internal
collision resolution)
TransmitQueues
Submission
doc.: IEEE 11-13/0221r2
Broadcom
802.11aa QoS Queues
Slide 7
Mar 2013
Classification to Access Categories and Transmit queues
VO
VO VI BE BKChannel Access
functions
TransmitQueues
A_VO VI A_VI BE BK
802.11aa introduces 2 additional queues for “alternate voice” and “alternate video”.
Submission
doc.: IEEE 11-13/0221r2
Broadcom
Current Bridge & AP Queue Architecture
Slide 8
Mar 2013
BSSID A
“Access Point”
MAC 1Port
MAC 2Port
MAC 3Port
VO VI BKBE
PortalPort
AP
BSSID B
MAC 4Port
MAC 5Port
MAC 6Port
VO VI BKBE
802.11 Portal
MAC Port
MAC Port
MAC Port
MAC Port
802.1 Bridge
MAC 7Port
Non-AP STA
MAC 8Port
MAC 9Port
MAC 10Port
MAC 11Port
MAC 12Port
Wired link
Wired link
Wired link
Wireless links
802.11 DS (Distribution System)
Non-AP STA
Non-AP STA
Non-AP STA
Non-AP STA
Non-AP STA
MAC Relay AP MAC Relay
MAC port instantiation per
wireless link
Submission
doc.: IEEE 11-13/0221r2
Broadcom
BSS Bridging “Common” Queue Architecture
Slide 9
Mar 2013
MAC 1Port
MAC 2Port
MAC 3Port
MAC 4Port
MAC 5Port
MAC 6Port
MAC Port
MAC Port
MAC Port802.1
Bridge
MAC 7Port
Non-AP STA
“Access Point”
MAC Port
MAC Port
802.1 Bridge
Wireless link
Wired link
Wired link
Wired link
Wired link
Wired link
Bridge’s Queues
Bridge’s Queues
Note: For the clarity of the figure, optional Tx intermediate buffers within the wireless MAC, handling the deferred access to the medium and the Tx retransmission on failure to receive an ACK are not represented.
Submission
doc.: IEEE 11-13/0221r2
Broadcom
802.11 – 802.1Q Default Priority Levels ACs default priority level mapping differ from 802.1Q-2012 default priority level
mapping
These mappings are informative only and could be freely modified
Slide 10
Mar 2013
802.1D 802.11 WMM 802.11aa 802.1Q-2012
PriorityPriority
LevelDesig.
Access Category
WMMPriority
AccessCategory
Priority Level
Traffic type
6 traffic types
4 traffic types
with SR Class A & B
with SR Class B only
lowest 1 BK AC_BKBackground BK
1 BK BKBE
BE
BE
2 - AC_BK 0 BE BE
0 BE AC_BEBest Effort BE
2 EECA CA
CA
3 EE AC_BE 3 CA
4 CL AC_VIVideo
A_VI 4 VIVO VO
SR-B NC
5 VI AC_VI VI 5 VO NC
6 VO AC_VOVoice
VO 6 IC ICNC
SR-A SR-B
highest 7 NC AC_VO A_VO 7 NC NC NC NC
Submission
doc.: IEEE 11-13/0221r2
Broadcom
802.11 Portal
Slide 11
Mar 2013
802.11-2012, Section 4.3.6: “Logical point at which MSDUs from an integrated non-IEEE
802.11 LAN enter the IEEE 802.11 DS.” 802.1Q-2012, Section 6.7.2: “A Bridge to an IEEE 802.11 LAN shall connect to an IEEE 802.11
Portal, which in turn connects to an IEEE 802.11 Distribution System. For the purposes of bridging, the service interface presented at the Portal is identical to the service interface presented at the IEEE 802.11 MAC SAP.
802.11 Portal
802.1 Bridge
802.11 Distribution System
ISS_SAP (M_UNITDATA)
DS_SAP (DS_UNITDATA)
Submission
doc.: IEEE 11-13/0221r2
Broadcom
802.3 – 802.11 MAC Relay
Slide 12
Mar 2013
802.11 to 802.11 MAC relay
802.11 to 802.3 MAC relay
802.3 to 802.3 MAC relay
802.3 to 802.11 MAC relay
802.11 MSDURx Queue
802.11 Tx Queue Selection
802.11 MSDUTx Queue
802.1x CtrlPort Filtering
802.11 MSDURx Queue
802.11 802.3MSDU Translation(“M_MA Portal”)
802.3 Tx Queue Selection
802.1x CtrlPort Filtering
802.3 MSDUTx Queue
802.3 MSDURx Queue
802.3 Tx Queue Selection
802.3 MSDUTx Queue
802.3 MSDURx Queue
802.11 Tx Queue Selection
802.11 MSDUTx Queue
Forwarding [Priority Handling]
802.3 802.11MSDU Translation(“M_MA Portal”)
Forwarding [Priority Handling]
Forwarding [Priority Handling]
Forwarding [Priority Handling]
Submission
doc.: IEEE 11-13/0221r2
Broadcom
802.1bz Bridge Data Plane Model
Slide 13
Mar 2013
802.03 MAC Port
802.11 MAC Port
_ISS_
802.1x Ctrl Port Filtering
_IS_ MAC Relay
Entity
_ISS_
Sec Y
_IS_
M_MA Portal
LLCLLC LLCLLC_IS_ _IS_
IS = Insecure ServiceSS = Secure Service
Submission
doc.: IEEE 11-13/0221r2
Broadcom
802.1bz Bridge Forwarding Process
Mar 2013
Slide 14
Active topology enforcement (8.6.1)
Ingress (8.6.2)
Frame filtering (8.6.3)
Egress (8.6.4)
Flow metering (8.6.5)
Queuing frames (8.6.6)
Transmission selection (8.6.8)
Reception Port
Transmission Port
Queue management (8.6.7) Queue management (8.6.7)
TransmissionPort State
Reception PortState
Filtering Database
• MAC DA• MAC SA• VID• Priority
802.1Q clauses to be modified
• MA / M Portal : - 802 11 - 802.3 MSDU translation • Multicast Handling - “Multicast Reflection” prevention
• 802.1x Ctrl Port Filtering
• 802.11 AC Queue selection
• No 802.11 PCF or flow control
• No shaping on EDCA medium access
• Common format “translation “
Submission
doc.: IEEE 11-13/0221r2
Broadcom
A (non exclusive) list of issues to address
• Common filtering of 802.11 and 802.3 MSDUs:• is a conversion to a “common format” within the bridge the right solution ?
• Double ingress/egress conversion for every MSDU (including MSDUs forwarded between the same medium) could be taxing on performances…
• Duality P2P and Distributed bridge model :• a BSS can not be modeled as P2P only….(see following slide)
• 802.11 link metrics / variation thresholds compatible with 802.1 wired link bridging protocols.
• standardize the metrics computation; characterize the wireless link
• AP / Non-AP STA “bridge port” command protocol• reliability and synchronization between ports
• MACSec / 802.1x / security interworking• key management, (end-to-end similar) crypto level
Slide 15
Mar 2013
Submission
doc.: IEEE 11-13/0221r2
Broadcom
A BSS can not be modeled as P2P only….
• Each Wireless link is a point to point link between the ports of 2 “independent“ hybrid (wired/wireless) bridges...
Slide 16
Mar 2013
Hybrid Bridge B
wl Port 1
Wr Port 2 Wr Port 3
Hybrid Bridge C
Wr Port 2 Wr Port 3
Hybrid Bridge A
wl Port 1
Wr Port 2 Wr Port 3
wl Port 2
wl Port 1
Wireless BSS
wl Port 2 wl Port 2
DLS
Submission
doc.: IEEE 11-13/0221r2
Broadcom
A BSS can not be modeled as P2P only….
• Each Wireless link is a point to point link between the ports of 2 “independent“ hybrid (wired/wireless) bridges...
• However, the wireless ports are controlled by the AP (association , encryption setup, bit rate selection, bandwidth management, metrics,…)
Slide 17
Mar 2013
Hybrid Bridge B
wl Port 1
Wr Port 2 Wr Port 3
Hybrid Bridge C
Wr Port 2 Wr Port 3
Hybrid Bridge A
wl Port 1
Wr Port 2 Wr Port 3
wl Port 2
wl Port 1
Wireless BSS
AP
Ctrl
wl Port 2 wl Port 2
DLS
Submission
doc.: IEEE 11-13/0221r2
Broadcom
A BSS can not be modeled as P2P only….
• Each Wireless link is a point to point link between the ports of 2 “independent“ hybrid (wired/wireless) bridges...
• However, the wireless ports are controlled by the AP (association , encryption setup, bit rate selection, bandwidth management, metrics,…)
• Need for a new Mgnt Protocol between the hybrid bridges and the BSS AP
Slide 18
Mar 2013
Hybrid Bridge B
wl Port 1
Wr Port 2 Wr Port 3
Hybrid Bridge C
Wr Port 2 Wr Port 3
Hybrid Bridge A
wl Port 1
Wr Port 2 Wr Port 3
wl Port 2
wl Port 1
Wireless BSS
AP
Ctrl
wl Port 2 wl Port 2
DLS
Submission
doc.: IEEE 11-13/0221r2
Broadcom
Revisiting the BSS Distributed Bridge Model option
• IEEE 802.1BR specifies a Extended Bridge beyond its physical enclosure using 802 LAN technologies.• In the BSS case, the AP will be the Controlling Bridge and the
non-AP STA will be Bridge Port Extenders
• The 802.1BR Port Extender Control and Status Protocol (PE CSP) provides a basic acknowledgement and retransmit mechanism
Slide 19
Mar 2013
Submission
doc.: IEEE 11-13/0221r2
Broadcom
References
[1] IEEE 802.11-2012
http://standards.ieee.org/getieee802/download/802.11-2012.pdf
[2] IEEE 802.1D-2004
http://standards.ieee.org/getieee802/download/802.1D-2004.pdf
[3] IEEE 802.11aa-2012
http://standards.ieee.org/getieee802/download/802.11aa-2012.pdf
[4] Wi-Fi WMM Specification v1.2
www.wi-fi.org/knowledge-center/published-specifications
[5] IEEE P802.1BR/D3.3
www.ieee802.org/1/files/private/br-drafts/d3/802-1BR-d3-3cb.pdf
Slide 20
Mar 2013