7925G best practice: http:/

Anthony Brandelli · ‎03-23-2015

First off this issue has existed since implementation, and I'm just curious if anyone has ideas on how to make improvements in performance, if at all possible. The problem is that after the phone goes off hook the first second of audio is either garbled and not understandable, or not present. After this initial delay the voice quality is fine, excellent in fact, even during roaming.

We have about 20 Cisco 7925g wireless IP phones deployed with CUCM 10.5.2, running the latest firmware 1.4(6)(3) The APs in use are a Motorola/Zebra AP 6522, this is why I haven't opened a TAC case, a deployment like this I'm sure would be considered "unsupported". The security method in use is WPA PSK, the phones are forced to only use 802.11a, and java has been disabled. Codec in use is either G711 or G722 depending on where the call came from, the issue exists using either. Calls between internal phones use SRTP + TLS, calls from PSTN use RTP.

I've done some research into this and there isn't a whole lot of information out there because most people deploy on Cisco APs, this wasn't an option. If anyone is able to provide insight I'm more than happy to listen. This problem is pretty minor, most users don't even notice, but it would be nice to have this delay eliminated if possible.

Leo Laohoo · ‎03-23-2015

The security method in use is WPA PSK, the phones are forced to only use 802.11a, and java has been disabled.

It is recommended that the wireless settings for the phones be WPA2 AES/PSK with CCKM enabled.

Here's something you can try, what happens if you have OPEN authentication of your voice SSID for the phones? Do the phones roam seamlessly with this settings?

Anthony Brandelli · ‎03-24-2015

Right, but CCKM is only available on Cisco wireless infrastructure which is part of the issue. The roaming is fine, its just the initial delay in audio cut through. I will get an SSID with open auth setup and see if this gets rid of the delay.

George Stefanick · ‎03-24-2015

I was going to say test this on a open ssid and see if you have the issue then start to add on the layers.

"Satisfaction does not come from knowing the solution, it comes from knowing why." - Rosalind Franklin
___________________________________________________________

Anthony Brandelli · ‎04-27-2015

Finally had time to switch back to this issue.. The issue still exists with an open SSID, no authentication or security.

Does anyone else have 7925s deployed "securely" as mentioned in the original post? Wondering if it's related to the security on the phones, but I realize that is just a guess.

Leo Laohoo · ‎05-05-2015

We have a grocery chain (and their hardware chain) use 7925G with Moto AP here in Australia. I have no idea if they actually work well (roaming) or not but I see their staff walking around with them.

decarvalhosylvain · ‎03-24-2015

7925G best practice: http://www.cisco.com/c/dam/en/us/td/docs/voice_ip_comm/cuipph/7925g/7_0/english/deployment/guide/7925dply.pdf

Do you configure call admission control ? QoS ?

Voice over IP with 7925G is critical.

Anthony Brandelli · ‎03-24-2015

The APs are managed by another team so I will have to talk with them about this, as far as I know WMM/QoS was configured but I'm not sure of specifics... Will see what I can find and report back.

decarvalhosylvain · ‎03-25-2015

the problem is between 7925G only ?

Anthony Brandelli · ‎03-25-2015

It's a problem whenever a 7925 is involved in the call flow, as the destination or source, the initial second of audio is not there for the most part. The other party in the call can be anything, a wired IP phone, PSTN caller, doesn't seem to matter in this case.

decarvalhosylvain · ‎04-01-2015

Learn how to get 792x wireless phones to work well in a Cisco Unified Wireless Network.

https://supportforums.cisco.com/document/112171/how-get-your-792x-wireless-phones-performing-reliablyhttp:/

Anthony Brandelli · ‎04-01-2015

I've read that, and a lot of it ONLY applies to Cisco wireless infra, keep in mind that I am deployed on Moto APs. I fully realize that this may be part of the problem, and that I may need to work with Moto on this, but I am trying to take it one step at a time. What does apply in a vendor neutral manner is applied/configured already, same with the call manager side/firmware versions.

I'm hoping to get an open SSID setup to test if this is security related on Monday, it's been an extremely busy week unfortunately.

7925g Slow Audio Cut Through