Piotr Wojciechowski

Cisco has recently released many some new versions of firmware for WLC (latest with major number 5.x) and its supporting software WCS (also 5.x). Good that they are patching and implementing new features in their software but fast developing process causes some incompatibility problems. Here are two of them you have to keep in mind.
First of all current WLC firmware version 5.0.148.0 does not support old lightweight access points - 1000 family. This is big disadvantage because many networks are still using them as they were quite cheap and they are EoS not for a long time. There is no info from Cisco if future releases of new software will still support old devices.
Second are incompatibilities between WLC firmware supported by each version of WCS. In example latest release of WCS (5.0.56.2) does not support WLC firmware 4.2.99.0 and 4.2.112.0, which are two latests from 4.2 mainline. This all causes that engineer have to be really careful deciding which version of firmware and software load on devices.