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Poor perfomance of smartphone/cordless phone on Cisco WLC 2504


Hi all,

we have a couple of Cisco 2504 WLC in active/standby mode, running version and with 30 AP associated.

AP model are: AIR-CAP1702I-E-K9 and AIR-AP1852E-E-K9.

Cordless and smartphone can join to 2 different SSID which can run both to 2.4 and 5 Ghz and Qos settings are one on "gold" and the other one on "platinum".

Aironet IE is enabled for both SSID.

Regardless of SSID, phones present bad performances in which voice sometimes disappears (for examples  on 10 words spoken you can hear just 5/6). During real time test, I have noticed that signal strenght was good, similar to this:

Signal Strength: -32 dBm Signal Quality: 67 dB Connection Speed: 54 Mbps Channel Width: 20 MHz
802.11g (2.4GHz) Spatial Stream: 0


The same happens with 72 Mpbs of speed.


Ping to this cordless during test was around 1% of packet loss.

Another thing I have noticed is that during roaming between APs, voice was totally mute, and after roaming speaking was still bad. 


So, roaming probably is a problem, but the big one is that performance are always poor. Do you have any idea about what we can manage to improve voice quality?


Thanks in advance,






3 Replies 3

Flavio Miranda
VIP Mentor VIP Mentor
VIP Mentor


   Voice over Wifi is complex.  I´d recommend this doc as the reason can be many things.


 This attached guide might be helpful

Haydn Andrews
VIP Engager VIP Engager
VIP Engager

First I would be migrating to 5GHz only for voice.

Would have a WIFI survey conducted to ensure meeting device requirements - normally SNR better than 20, signal -67 cell edge, 20% cell overlap, retransmits <2% and 1 way delay <150ms

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Leo Laohoo
VIP Community Legend VIP Community Legend
VIP Community Legend

What is the model of the cordless phone?

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