VoWLAN

[notes]
VoWLAN

Recommendation to place all antennas 1 to 2 wavelengths from highly reflective surfaces.
2.4Ghz = 4.92 inches (12.5 cm)

• 5GHz = 2.36 inches (6 cm)

The human head and body attenuates 5db of RF signal
If the antenna is in the body of the phone, the loss ~ 4db – 9db

Handsets do not have diversity antennas due to the length of the 2.4ghz wavelength distance (4.92in)

802.11A handsets do have a diversity antenna solution

DFS, 802.11h

When radar is detected:

• stop packet transmission within 200ms
• stop control transmission within 10 seconds
• avoid transmitting on the channel for 30 minutes
• scan a new channel for 60 seconds before transmitting

Cisco recommends that for voice apps, the cell edge be determined by using the actual phone at the desired data rate.

Voice packets sent between the AP and the phone are generally unicast RTP G711 packets with a typical size of 236 bytes.

Cisco recommends all APs have a maximum transmission power of 13dBm.

A call between two phones associated to the same AP counts as two active voice streams.

Guest anchor WLC – can support EoIP tunnels from 40 WLCs and supports 2500 simultaneous users and has forwarding capacity of 2gbps.

Multicast is not supported over guest tunnels.

One additional port number can be monitored for redirection: network web-auth-port