1. AP Architecture Changes Mike Moreton, STMicroelectronics
doc.: IEEE /xxxx
February 2004
July 2004
AP Architecture Changes Mike Moreton, STMicroelectronics
26th May, 2004
Mike Moreton, STMicroelectronics
Fred Stivers, Texas Instruments

2. Traditional AP Architecture
doc.: IEEE /xxxx
February 2004
July 2004
Traditional AP Architecture
Does not follow the 802.1D bridging architecture
Has the concept of a DS
Forwards frames within a BSS
Forwards frames between BSSes
The latter function can be implemented as an 802.1D bridged network
But this isn’t mandatory
While the MLME/MA architectural split does not constrain an implementation, it’s up to the implementer to check the security of any other architecture.
Mike Moreton, STMicroelectronics
Fred Stivers, Texas Instruments

3. TGi Modifications July 2004 Mike Moreton, STMicroelectronics
doc.: IEEE /xxxx
February 2004
July 2004
TGi Modifications
It’s different!
Mike Moreton, STMicroelectronics
Fred Stivers, Texas Instruments

4. July 2004
Why is it different?
TGi decided to adopt 802.1X port based authentication
802.1X assumes the architecture
Had to modify the architecture so that 802.1X would work
Mike Moreton, STMicroelectronics

5. July 2004
How is it different?
Every AP is assumed to have an 802.1D bridging function
This is responsible for the port based authentication
Avoids duplicating a lot of text from 802.1X in i
The intra-BSS relay function doesn’t exist
Otherwise it would be possible to bypass the port based authentication
All frames have to be passed to the 802.1D bridging function.
Mike Moreton, STMicroelectronics

6. The 802.1 View of 802.11 Each STA that associates creates a new port
July 2004
The View of
Each STA that associates creates a new port
Encryption localises frames to their correct ports
IEEE MAC Relay Entity
Port for STA 1
Controlled Port
Port for STA 2
Controlled Port
Port for STA 3
Controlled Port
Port for STA 4
Controlled Port
Port for STA 5
Controlled Port
Mike Moreton, STMicroelectronics

7. doc.: IEEE /xxxx
February 2004
July 2004
Multicast/Broadcast
Strictly we should copy each broadcast frame to every port.
As it is, i is a strange mixture of star and shared topologies
star for unicast
shared for broadcast
One possible model is to have an additional (always present) virtual port for broadcast only
Or just fudge it – pretend a copy of each frame is sent to each port, but that the MAC somehow re-unifies them into one.
Bullet 1: This would be good from a security perspective, but obviously wasteful of the medium
Bullet 3: Remember – this is only an architecture. Requires new concepts in the architecture.
Mike Moreton, STMicroelectronics
Fred Stivers, Texas Instruments