7925G receives low RSSI

[Koevi Vong]

Hi,

I am currently working on a 7925g issue where compared to a 7921 handset, the 7925G would show a significantly lower RSSI than the 7921. For example, in one area the 7921 shows -59 RSSI and the 7925G shows -76 RSSI.

The 7921 is constantly -10 to -15> better then the 7925G, this is tested by walking around the area with both phones in site survey mode side by side.

Even though site survey tools (Airmagnet) and 7921 handsets shows good signal, when using the 7925G handset it is 20-30% worse. Does anyone else have this issue as well?

Thanks

[Rasika Nayanajith]

Does 7925G have latest firmware on it ? Is this common for any 7925G customer having ?

What is the RSSI value shown in "show client detail <mac-address>"

Rasika

[Leo Laohoo]

Make sure your 792XG handsets are running a minimum of 1.4(3) firmware.  The older firmware versions have difficulty in roaming and can be a liability.

[abwahid]

 Hi,

yes check with the latest firmware release 1.4(5) and alot of other factors may involve in showing the lower RSSI in site survey of 7925G

Go through the below deployment guide as well.

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

[jmeachum]

Are you sure that they are both looking at the same band?  It appears to me that one is configured for Auto A and the other is configured for Auto.

If the 7921 is looking at the 2.4Ghz band and the 7925 is looking at the 5Ghz band then your results may be normal.

[Abhishek Abhishek]

Voice Quality Deteriorates While Roaming

Check the RSSI on the destination access point to see if the signal strength is adequate. The next access point should have an RSSI value of -67 dBm or greater.

Check the site survey to determine if the channel overlap is adequate for the phone and the access point to hand off the call to the next access point before the signal is lost from the previous access point.

Check to see if noise or interference in the coverage area is too great.

Check that signal to noise ratio (SNR) levels are 25 db or higher for acceptable voice quality.
Delays in Voice Conversation While Roaming

Use the Site Survey Utility on the Cisco Unified Wireless IP Phone 7925G to see if there is another acceptable access point as a roaming option. The next access point should have an RSSI value of 35 or greater to roam successfully.

Check the Cisco Catalyst 45xx switch to see if it has the correct version of Supervisor (SUP) blades. The blades must be versions SUP2+ or higher to prevent roaming delays.
Phone Loses Connection with Cisco Unified Communications Manager While Roaming

Check for the following configuration or connectivity issues between the phone and the access point:

•The RF signal strength might be weak. Use the Site Survey Tool and check the RSSI value for the next access point.