competitive
description and
Address 4 field (4 addresses) usually is in reference to WDS (wireless distribution system.) WDS allows modes such as bridging and repeating and is handled at the AP/Bridge/Repeater level and the card adapter doesnt know or care about the 4 addresses. The WAP54G supports WDS but it may or may not work or talk to smartbridges using WDS.
From SmartBridges website: smartBridges devices use Address-4 field, which is an optional field as specified by IEEE 802.11b standard. If any IEEE 802.11b compliant wireless access points supporting this field, then it can be used with Client-Bridge mode.
In this case, I would recommend you to use the airBridge series which is a standard Ethernet client device and will work with any access point supporting the 802.11b standard instead of using the airPointPRO series as client devices (CB mode). This will prevent you from having any incompatibility issues with normal 802.11b Access points.
End Smartbridge
The AirPointPro uses WDS for bridging, the AirBridge is a normal ethernet bridge and will talk to any AP. I think what
they are trying to say is that you may need an AirPoint (in place of your WAP54G) to use wireless ...note this sentance:
This will prevent you from having any incompatibility issues with normal 802.11b Access points.