What is the best practice for setting the WLC v7.0 use of WLAN QoS settings to support SIP phones on a VoWLAN?

Static CAC reserves a fixed percentage of bandwidth for voice, ensuring consistent call quality by limiting concurrent calls per radio. SIP call snooping enables the WLC to inspect SIP INVITE and BYE messages so it can accurately track active call state and enforce admission control without requiring TSPEC requests from the phones.

Without SIP call snooping, the WLC cannot monitor SIP signaling to track active calls, making static CAC unable to accurately count and enforce call admission limits.

Load-based CAC measures aggregate channel utilization to make admission decisions but is less deterministic than static CAC for SIP phones that do not send TSPEC requests.

Load-based CAC without SIP call snooping provides no visibility into SIP call state, resulting in inaccurate admission control for SIP-based voice.

TSPEC-based admission is designed for 802.11e/WMM clients that issue explicit TSPEC requests, but SIP phones typically do not send TSPEC, making TSPEC-combined CAC unreliable for SIP VoWLAN.