cisco 7925 wifi phones calls disconnecting

[yamahagrizz]

Our Healthcare organization has Meraki MR32 for access points. Does anyone have Cisco 7925G wifi phones running on MR32? users keep stating the calls our dropping.

[MilesMeraki]

Have you attempted to troubleshoot this issue in great detail? If it's only the one user that's complaining I'd assume it's a user specific issue. 

Access the Dashboard and check the Signal strength of the wireless phone, it could very well be in an area within the room which has a "weak" signal strength. (The phones wireless so you'll probably have to walk around with the phone to replicate the users movement when having issues.)

It could be the case that the phone's roaming between AP's which is causing the problem. If this is the case attempt to turn on 802.11r. 

If you're still having issues i'd recommend calling Meraki support while replicating the issue above.

[yamahagrizz]

When you ask the user/users they just say it's garbage and they don't tell you any specifics, that is what makes troubleshooting so challenging. I did enable 802.11r on two different networks that I have to see if that helps the issue. We also have ascom i62 phones in our environment that don't support 802.11r. Wireless is a different beast that is for sure.

[Kujoh]

I enabled 802.11r on our network and it really made a difference. We still see some dead spots as you walk around using a Cisco 7921 but the zones of static are much abbreviated and it does not disconnect the call. Thanks for the information!

[yamahagrizz]

I enabled 802.11r on all our networks as well. Do you have to enable anything else for this to work? in other words do you have to do anything on the phones or do they automatically do 802.11r roaming once it's enabled?

[Sameh_Sackla]

Have you checked this article about compatibility with Cisco 7925 VoIP phones? https://documentation.meraki.com/MR/Other_Topics/Compatibility_with_Cisco_7925G_VoIP_Phone Thanks

[LeoG]

In addition to the guide provided by Sameh_Sackla, I would not recommend by any means using 802.11r with this Cisco Phone.

It comes from a time where 802.11r did not exist, and while it can still theoretically connect to a network where 802.11r is enabled (from what I can see in the Cisco forums) it is strongly recommended not to turn it on.

Have you done an active Site Survey? It is very important to see these parameters are on comply with VoIP requirements (plus any additional ones you see on the deployment guide, but these are the main ones):

- Co-Channel Interference (no more than three APs heard at the same time, with a difference of at least 20-25 dBm SNR on the non-overlapping part)

- Signal received (between -67 and -65 dBm over all the cell)

- SNR (more than 20 dBm if possible).

- Jitter(the closest to 0 the better). This can have a high impact on your calls.

Additionally, on the LAN side, everything should be able to handle QoS marking and prioritize the traffic accordingly to this tagging.

Here are some documentation you would like to see about how to deploy a wireless network and how to tune it:

https://documentation.meraki.com/MR/WiFi_Basics_and_Best_Practices/Channel_Planning_Best_Practices

https://documentation.meraki.com/MR/WiFi_Basics_and_Best_Practices/Wireless_fundamentals%3A_Signal-t...

And we also have a general guide to deploy voice over Wireless, you may find it very useful:

https://documentation.meraki.com/MR/Deployment_Guides/Wireless_Voice_Deployment_Guide_(CVD)

And two very specific - the first one is part of the deployment guide, the second one a Cisco guide for deploying this phone with Cisco Meraki wireless infraestructure.

https://documentation.meraki.com/MR/Deployment_Guides/Wireless_Voice_Deployment_Guide_(CVD)#Cisco_79...

https://www.cisco.com/c/dam/en/us/td/docs/voice_ip_comm/cuipph/7925g/7_0/english/deployment/guide/79...

Hope this helps 

[Kujoh]

I have the same issue with a Cisco 7921. I have to stop any movement and answer the call, hoping that it won't cut out. For the most part that works. Continuing to move from the coverage of one AP to another will cause dead air, for sure.