Specifications

Chapter 4 Wireless LAN Option
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4.3 Wireless Pseudo VLAN
With more deployments of IEEE 802.11b Wireless LAN in the public premises such as
the airport, university campus and fair ground, there has been a rising concern over the
privacy level that the 11Mbps wireless LAN can offer. Can you imagine yourself
surfing the Internet in the commercial hotspots and someone is peeking at your files?
WEP (Wire Equivalent Privacy) provides only privacy against unauthorized access to
the wireless network but assuming those who have already gained access to the network
to be “trusted”. While privacy remains an issue for most public Wireless LAN
implementations, the release of Wireless Pseudo VLAN, combines with WEP, brings
another level of privacy among users or groups of user.
The Wireless Pseudo VLAN defines a single Wireless LAN into multiple Virtual LANs.
Communication is only possible between wireless nodes of the same VLAN. The
Wireless Pseudo VLAN may be defined to contain a single user for each VLAN, or a
group of users per VLAN, referred as Per Node and Per Group respectively.
4.3.1 Per Node Wireless Pseudo VLAN
Per Node Pseudo VLAN, if implemented, segregates every wireless node in
its own Pseudo VLAN. Wireless clients may access to the Internet. However,
communications among wireless nodes are blocked. This type of Pseudo
VLAN is most suitable in public premises such as the airport. Users who surf
the Internet via the wireless network in the airport can be certain that their
files are not open for other users to view. WEP (Wire Equivalent Privacy) may
be defined in conjunction with Per Node Pseudo VLAN, providing security
against unauthorized access to the wireless network. Refer to Figure 4.3a.
Figure 4.3a Per Node Pseudo VLAN segregates every wireless clients in their own
VLAN