802.11ac is backward compatible with 802.11n and 11a, and operates in a mixed mode supporting 802.11a/n/ac clients in the 5GHz band. So your 802.11ac APs can transmit to 802.11ac clients on 80MHz channels, 802.11n clients on 20/40MHz channels, and 802.11a clients on 20MHz channels. However, falling back to 20/40MHz channels will impact performance for 802.11ac clients, so it is important to assign channels in your environment to balance performance among your specific client base.
802.11ac, when it arrives, has a few new effects on existing 802.11a/11n deployments even if the deployment is not upgraded to 802.11ac immediately: (1) the wider channel bandwidths of neighboring APs require updates to radio resource measurement, or RRM (and in particular the dynamic channel assignment algorithm), and (2) 802.11a/11n wireless intrusion protection systems (WIPS) can continue to decode most managements frames such as beacon and probe request/response frames (that are invariably sent in 802.11a format) but do not have visibility in data sent in the new 802.11ac packet format.
802.11ac is backward compatible with 802.11 a/b/g/n.
One of the biggest issue with implementing 802.11ac is the amount of non-overlapping channels. Since 802.11ac works only with 802.11a radio, the number of non-overlapping channels drop to four. If you have a dense deployment of AP this will be a significant challenge.
Be aware that some wireless clients advertise themselves as "802.11ac ready" but these clients will NEVER be able to push at 802.11ac. A good example is Samsung's Galaxy. How do you expect this model to push 802.11ac speed with only one radio?
Transferring Crash file from standby: Login to the Active WLC in HA.
From CLI: (Cisco Controller) >transfer upload datatype crash (Cisco
Controller) >transfer upload filename (Cisco
Controller) >transfer upload mode tftp (Cisco Controller) >transfer
This is the start of a display filter cross reference between Wireshark
and OmniPeek. The 1st installment is a table of advanced filters. More
filters will be added as time allows. It is a living doc, so check back
for changes every so often Please feel f...