roaming APs on 7920

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Dec 18th, 2003
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I have yet to be able to roam well between APs using the 7920 phone. I right now have 2 1230 APs running c1200-k9w7-tar.122-13.JA1. I have them spaced at AP1 channel 1 AP2 channel 6. Site survey mode picks up both APs. The APs are on the same VLAN. When I walk toward AP2 I see the signal weakening from AP1 and getting stronger to AP2. However the actual kick over takes a few seconds like about 10 seconds. In the mean time due to poor signal from AP1 the call quality gets really poor. And sometimes the call is even lost before the phone switches APs. Ive tried adjusting the TX power on the 7920 to 5 and 1. With very little difference. any suggestions?

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belz-e Thu, 12/18/2003 - 13:39
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just to add. I am not using any encryption or authentication. The SSIDs are the same on both APs. And the signal strengths are set to MAX

j.boyson Fri, 12/19/2003 - 16:39
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I'm working on a larger scale implementation. having same problems. Turn the power down to 20mw or below.

j.boyson Fri, 12/19/2003 - 16:57
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I just read your post again and see you've already decreased power. Have you seen any debugs? What Antennas are you using? We're having major issues. We have about 30 APs and 100 7920s. Cisco is on site with us here. Slowly making progress. We've updated phone firmware to higher rev that 1.0.5. It did not fix the issue.

g.rienstra Mon, 01/12/2004 - 09:01
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HI,


After december 19th...Did you make any progress with Cisco? We use the latest rlsd software on the phone now (1.0.6) but still see similar issue's.

Alos using 1230 AP with 4941 'duck-antennas)

128 bit WEP , and VLAN's no fancy stuff...


If you have some news please let me know.


Reg

Goen

nuno.santos Mon, 12/22/2003 - 04:22
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Hi,


check the RSSI values on the site survey phone results! Maybe you have both signals with the same power or very close and phone gets confused trying the association consecutively on both aps. Try to reduce the power or change the positions to higher the distance between them. Just a suggestion.


Nuno

ED CARMODY Tue, 12/23/2003 - 20:06
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I just visited a retail store with (7) APs, and around a dozen 7920 phones. I got called in to troubleshoot poor-quality and dropped calls. I was able to get it nailed down to very sub-par roaming.

We are having the same issue. What we are discovering is that it's not the wireless, but the switches. We are seeing 200 to 400 voice packets dropped through the network during the roam. This is equal to 4 to 8 seconds of voice. The wireless phone seems to roam well and you see the voice packets "From" the wireless phone just fine. But voice packets "to" the wireless phone are dropped for a period during the roam. What type of switches are you using??

jakevargas Wed, 02/11/2004 - 14:13
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We are having the same issue. 5 seconds for a transition to take place and its not the switches causing our problem, it's the actual reauthentication time. No idea what to do. We offloaded the auth from the radius server to the actual AP's to no improvement. We just need a 100ms or less roam to take place...no joy.

ndoshi Fri, 02/13/2004 - 14:37
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  • Cisco Employee,


http://www.cisco.com/en/US/partner/products/hw/phones/ps379/products_white_paper09186a00801ca827.shtml


If you are using wep than roaming time should be 100mes aprroc and with leap it should be between

200-400 msec .If it is 1-10 range than it is issue.


One of the location we had 4000 switch we upgraded

the sup to sup2plus and we saw improvement .At same

time we fine tuned their config on core network and

switches .


This may not be root cause on all cases but food for thought ....


Thankd


michaelgillespie Wed, 06/30/2004 - 12:03
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Yes, the sup1 and sup2 w/ Catalyst 45XX are not adequate to support seamless roaming. Must have at least sup 2+.


If not able to roam, ensure you have adequate overlap of non-overlapping channels. Same SSID, VLAN, security settings should be configured. Refer to http://www.cisco.com/en/US/products/hw/phones/ps379/products_white_paper0900aecd800f6d97.shtml for more info.

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