The Channel scanning algorithm introduced into the 1.3.4 firmware as part of the interband roaming feature can have an adverse effect on voice performance in certain environments. The scanning algorithm was targeted at open plan environments were coverage cells were large, and the phones would remain in the coverage cell for 5 to 10 seconds or more. This algorithm has worked well in the environments for which it was targeted. But in those environments where cell coverage is small, such as corridors with turns, fire doors and non line of sight, the algorithm has proved not to be optimal in every usage case.
The scanning algorithm does not scan the channels aggressively enough in these environments, which can lead to the phones appearing to remain connected to an Ap that is no longer the best candidate as the candidates change rapidly. The AP to which the phone is connected is normally displayed in red in the neighboorlist of the phones.
Cisco is preparing a new scanning algorithm to mitigate this behavior and provide more aggressive scanning, which should reduce the incidence of voice drops. The new scanning algorithm should not be considered as an alternative to a voice deployment best practices, the guidelines for which are detailed in the 7921 and 7925 deployment guides.
The new code can only be obtained via a TAC case after verifying that the Wireless infrastructure is inline with the voice deployment guidelines and that there is necessary RF coverage.
UPDATE January 2013: New algorithm is integrated as of 1.4.2 code. It is recommended to run latest 1.4.3 code.
For you refference here are the 7921 and 7925 deployment guides.
Hello,there was another posting which explained the 802.11ac Current Rate Field in detail.Unfortunately this doesn't aply on 11n rates.I can see something like m7b2, m6-2, m5t2 on aironet 2700i ap.I think the first digit is the mcs index and the last show...
i have a query on Local Automatic Channel assignment And Leader automatic channel assignment, there is channel update interval 24hours and 600 seconds respectively. what is difference between two and how it will impact our environment. Note: wl...
HelloI have controller moblity express 1815i 1) If i want to increase Bandwith for AP1815i Cisco , how I can do that? 2) does it make sense if i change pool address ip from VLAN 30 with 10.2.30.0/24 to VLAN1 with 192.168.0.0/24 ,&nbs...
When I read about Mesh APs, the Cisco book said the AP shoud be configured as mesh mode... Now I'm reading about special-porpuse on LAPs, one of them is bridge mode, and its description says you can create a mesh network with it So what could be the ...