06-05-2010 06:42 PM - edited 03-21-2019 02:39 AM
We replaced our Cisco 877W with a brand new UC-540 from Cisco in January 2010.
We setup the UC-540 via wizard. Upon use, we immediately noticed a decrease in wireless signal strength and dropped connections every three minutes or so - even when within feet of the device when compared to the Cisco 877W.
We first attributed the issue to the slightly more enclosed mounting location, or the additional metal shelving. . We were just about to pay for a professional site survey to rule out radio interference when we discovered a a reference from http://uc500.com/en/uc520w-built-wifi-fluctuating-rf-levels.
We decided with Cisco's STAC to test the following solution before RMA'ing the unit as faulty;
antenna receive right
antenna transmit right
It worked! Our signal strength is much better and we have yet to drop a connection after two weeks of regular use.
Did Cisco fail to consider that there is only one antenna in this device?
06-05-2010 10:41 PM
Excellent stuff Brook,
Thank you very much for this input and bringing this to the attention of the wider public, your comments are indeed accurate and relevant.
I looked up this issue and found this issue mentioned in an release note regarding CCA version 2.
see reference:
It mentions an issue discovered and CSCtg07290 workaround;
CSCtg07290 | CCA should set antenna TX/RX to right (primary) under dot11 radio interface on UC 520 and UC 540 platforms with integrated wireless Symptom Poor audio and dropped calls for wireless phones connected via the integrated wireless access point on the UC 520. Workaround The only workaround for this issue is to access the device CLI and configure the "right" setting under the dot11 radio interface for both transmit and receive. UC520(config-if)#antenna ? UC520(config-if)#antenna receive ? |
regards Dave
06-05-2010 10:46 PM
Thanks, Dave.
06-06-2010 08:38 PM
Hi Brooke,
Found this one out the hard way, good o'l Dave Harper pointed this out to me after a week and a half of torment with one client... I am so glad you posted this as I totally forgot to
I am not sure why a dipole chipset was put in one of these boxes although they only carry one antenna, pity there is no way to add the secondary antenna and use the chipset to their full advantage.
Cheers,
David.
06-06-2010 10:52 PM
Ugh. I had to reset my UC-540 and now I cant find my way to Dot11Radio Interface again.
The following is useless to me as far as assisting in the configuration of the device;
UC520(config-if)#antenna ?
gain Configure Resultant Antenna Gain
receive receive antenna setting
transmit transmit antenna setting
UC520(config-if)#antenna receive ?
diversity antenna diversity
left antenna left/secondary
right antenna right/primary
Would someone mind providing the correct commands starting after logging into the device via telnet.
Thanks,
06-06-2010 11:29 PM
Hi Brooke,
You need to go to the interface to do it, please see below:
ROUTER#(config)#interface Dot11Radio0/5/0
ROUTER#(config-if)#antenna receive ?
diversity antenna diversity
left antenna left/secondary
right antenna right/primary
ROUTER#(config-if)#antenna receive left..errrr or is it right MEH! i forgot LOL
Have a go at that.
Cheers,
David.
06-07-2010 02:22 PM
Everything is tied to the right amtenna on my UC540. I was doing;
ROUTER#(config)#interface Dot11Radio0
and
ROUTER#(config)#interface Dot11Radio1
but getting no where.
For other resons I reset the device to defaults and its working fine. It must have been an upgrade along the way that set the antenna's back to diversity.
That just goes to show you that upgrades sometimes have no respect for your existing configuration and if you dont have a need for the fixes upgrades provide, the upgrade may make things worse.
Thanks David!
06-07-2010 03:18 PM
Hi Brooke,
That just goes to show you that upgrades sometimes have no respect for your existing configuration and if you dont have a need for the fixes upgrades provide, the upgrade may make things worse.
I'm a sucker for new upgrades, it gets me into a lot of trouble, I call it the Homer Simpson syndrome, I keep going back for more even after I have burnt myself.
Cheers,
David.
06-09-2010 06:16 PM
Well, resetting it to factory defaults did not, in fact resolve the random drops and waves of poor signal strength.
The problems reared their head after just a few days.
Here is what I just tried, based on David Trad's advice;
ROUTER#config
ROUTER#(config)#interface Dot11Radio0/5/0
ROUTER#(config-if)#antenna receive ?
This returns the current (and factory default) settings, below
diversity antenna diversity
left antenna left/secondary
right antenna right/primary
If I type;
ROUTER#(config-if)#antenna receive right
Sets receive to the right antenna - the only one physically present
ROUTER#(config-if)#antenna transmit right
Sets transmit to the right antenna - the only one physically present
And run
ROUTER#(config-if)#antenna receive ?
or
ROUTER#(config-if)#antenna transmit ?
I get;
diversity antenna diversity
left antenna left/secondary
right antenna right/primary
NOTHING has changed.
What am I missing?
Is there something to do with the diversity command?
06-10-2010 03:46 AM
Hi Brooke,
What am I missing?
These may be stupid questions but I think we need to start somewhere
I have one UC-500 deployed right now where we have had to force it onto one particular channel, it would not work on any other due to congestion in the area, even still it is not stable as much as what an 877W would be or an 1141, but it is doing the job just (and for now).
You can also consider the following:
Might not be the best of options, and also the most simplisic questions, but it would be a good place to start in my mind.
Cheers,
David.
06-10-2010 06:35 AM
David,
Thanks as always for your reply.
The unit is in the same location it was when STAC made the changes to the antenna that caused the unit to work much better.
The unit is still surrounded by the same CAT5e and power cables, but not too many.
Yes, there are a lot of WAPS in the building, but still the unit worked well after the changes made by Cisco's STAC to use the right antenna.
The appliance is stll set to WPA2.
The channel was 8 before, and it is 8 now. I may try setting it to "least congested at startup", but I remain convinced the issue is due to the factory default settings configuration, which assumes a right and left antenna. There is no left antenna.
I wish I could remember what else the Cisco STAC did, because it made the wireless work very well. This time I will record/document the session and when/if it works, post it back here.
Maybe Cisco STAC has a record of the session?
06-10-2010 06:40 AM
If you have the case #, I will look it up for you.
06-10-2010 06:52 AM
Thanks Steve!
It was one of these three. Most likely Case# 613652985 or 614554143.
CASE HISTORY
CASE ISSUE CISCO STAC REP
=============== ==================== ================
Case # 613652985 7975G Firmware upgrade woes Derrick
Case# 614554143 7975G VPN Client "This key not active here" ?
Case# 614554255 Multiple Gateway IP’s how to in CLI? Jason
" Single Number Reach being wonky "
Case# 614605353 Wireless sucks again after reset to defaults Jason
06-10-2010 07:15 AM
There is no relevant data in any of these opened from your site.....
But Case=614605353 has **no** data, looks like they are waiting to hear back from you????
Maybe it was discussed and not documented.
Sorry ;-)
Message was edited by: Steve DiStefano
06-10-2010 07:32 AM
I found something...
A different case from a different site....
"try manually setting the antenna tx and rx to right instead of diversity"
F340.02.18-UC520W-2(config-if)#antenna ?
gain Configure Resultant Antenna Gain
receive receive antenna setting
transmit transmit antenna setting
F340.02.18-UC520W-2(config-if)#antenna receive ?
diversity antenna diversity
left antenna left/secondary
right antenna right/primary
...
...
"We have made the changes to both the TX and RX. Great news... this has
fixed our issue.. Thanks for your help
Seems like antenna is set by default to diversity.
provided instructions to set the antenna tx/rx to right (primary)"
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide