I asked if the firmware upgrade makes the older 350 Series Wireless Bridge to support 802.1q.
The answer was that it is possible to upgrade both 350 and 340 Series Wireless Bridges to support 802.1q.
Which version of firmware is needed for VLAN support for 340 Series and 350 Series?
The latest version for 340 Series available on the net is v8.80, still on the menue doesn't appear anything after upgrade.
Thank you for your help!