As per the 7925 Deployment Guide, these are the guidelines for Unified Wireless deployment for voice.
• Ensure CCKM is Enabled if utilizing 802.1x authentication
• Set Quality of Service (QoS) to Platinum
• Set the WMM Policy to Required
• Ensure Session Timeout is enabled and configured correctly
• Ensure Aironet IE is Enabled
• Set DTPC Support to Enabled
• Disable P2P (Peer to Peer) Blocking Action / Public Secure Packet Forwarding (PSPF)
• Ensure Client Exclusion is configured correctly
• Disable DHCP Address Assignment Required
• Set MFP Client Protection to Optional or Disabled
• Set the DTIM Period to 2
• Set Client Load Balancing to Disabled
• Set Client Band Select to Disabled
• Set IGMP Snooping to Enabled
• Enable Symmetric Mobile Tunneling Mode if Layer 3 mobility is utilized
• Enable Short Preamble if using 2.4 GHz
• Enable ClientLink if utilizing Cisco 802.11n capable access points
• Configure the Data Rates as necessary
• Enable CCX Location Measurement
• Configure Auto RF as necessary
• Set Admission Control Mandatory to Enabled for Voice
• Set Load Based CAC to Enabled for Voice
• Enable Traffic Stream Metrics for Voice
• Set Admission Control Mandatory to Disabled for Video
• Set EDCA Profile to Voice Optimized or Voice and Video Optimized
• Set Enable Low Latency MAC to Disabled
• Ensure that Power Constraint is Disabled
• Enable Channel Announcement and Channel Quiet Mode
• Enable CleanAir if utilizing Cisco access points with CleanAir technology
• Configure Multicast Direct Feature as necessary
• Set the 802.1p tag to 6 for the Platinum QoS profile
Related Posts
1.7925G – Power Management
2.7 Guidelines for Better VoWLAN
3.WLC Config for VoWLAN
4.
mrn-cciew 
“Ensure Session Timeout is enabled and configured correctly” – why so? I thought it would be better to increase or disable it…
I found an answer in your following post)
Great 🙂
For others benefit here is the extract
“Configure Enable Session Timeout as necessary per your requirements. It is recommended to either disable the session timeout or extend the timeout (e.g. 24 hours / 86400 seconds) to avoid possible interruptions during audio or video calls. If disabled it will avoid any potential interruptions altogether, but enabling session timeout can help to re-validate client credentials periodically to ensure that the client is using valid credentials.”
HTH
Rasika