topic Re: Wireless clients face latency issues in Wireless

Wireless clients face latency issues

ravisambaji — Sun, 04 Jul 2021 04:14:44 GMT

Hi Friends,

I have Cisco 1140 access points and 5508 controller in my network. I have configured 2 SSIDs. One SSID is working fine, we have issue with second SSID. Clients getting connected to second SSID are facing the latency issue, latency is around 1000 ms where as with first SSID the latency is around 100 ms.

The layer-3 gateway for the user VLANs is in switch. The link between controller and L3 switch is trunk port and we have allowed only required vlans on the trunk. We even configured seperate test ssid and mapping to different vlan id.. still we face the same issue.

What could be the issue, help is appreciated.

Regards

Ravi

Re: Wireless clients face latency issues

Scott Fella — Thu, 15 Dec 2011 06:20:32 GMT

That is a high latency. Did you try to isolate where the latency starts? If you did a trace route is it somewhere in the wan? I'm guessing it's over the wan with those times.

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Re: Wireless clients face latency issues

ravisambaji — Thu, 15 Dec 2011 06:23:40 GMT

Hi Scott,

When user pings his gateway ip address, we see the latency. i don't see the latency in the wan. where is latency for users connecting to other SSID is less than 100 ms.

Regards

Ravi

Re: Wireless clients face latency issues

Scott Fella — Thu, 15 Dec 2011 06:27:36 GMT

Okay... So now is it one user or all users on that SSID. Have you looked at the logs on the wlc and even in the switch to see if you have errors. If you connect a wired pc to that subnet, do you still have high ping times?

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Re: Wireless clients face latency issues

ravisambaji — Thu, 15 Dec 2011 06:29:08 GMT

when i connect the wired users on the same subnet, i don't have the latency issues.

Re: Wireless clients face latency issues

Scott Fella — Thu, 15 Dec 2011 06:34:21 GMT

What are the ping time from the wlc to the gateway. Is it one user or everyone?

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Re: Wireless clients face latency issues

ravisambaji — Thu, 15 Dec 2011 06:35:54 GMT

the ping latency from WLC to gateway is less than 10 ms.

Re: Wireless clients face latency issues

Scott Fella — Thu, 15 Dec 2011 06:39:56 GMT

Then I would check the client device then. Maybe a driver issue or configuration issues. Seems to be pointing to that if your ping times frim the wlc to that gatway is low. You can run a debug on the client also if you want.

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Re: Wireless clients face latency issues

ravisambaji — Thu, 15 Dec 2011 06:48:38 GMT

we have tried with multiple laptops, same laptop works fine with other SSID.

Re: Wireless clients face latency issues

George Stefanick — Thu, 15 Dec 2011 06:50:58 GMT

Have you tired taking the WLC and wireless out of the mix and stretch the vlan to the wired side and see what happens?

Re: Wireless clients face latency issues

Scott Fella — Thu, 15 Dec 2011 06:53:41 GMT

Try no authentication and see if the problem goes away. You need to try to eliminate all factors. Is both SSIDs setup using the same authentication method? If you swap the interface around does this issue still exist with the SSID or the subnet? If you are using PSK, try to use either wpa/tkip or wpa2/aes, not both at the same time.

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Re: Wireless clients face latency issues

ravisambaji — Thu, 15 Dec 2011 06:53:46 GMT

ur trying to suggest there is problem in the wired network but not the wireless part. Iam a data guy have ensured there is no problem in this portion. need to look at if some of the features in the wlc related to ssid or vlan etc can be enabled/disabled to get it back to working.

Re: Wireless clients face latency issues

ravisambaji — Thu, 15 Dec 2011 06:55:42 GMT

tried with no authentcation as well.. no luck..

Re: Wireless clients face latency issues

George Stefanick — Thu, 15 Dec 2011 07:01:16 GMT

I would try swapping the interfaces as scott suggested or build a different WLAN for testing. Strip it down to nothing ... Also both your SSIDs, do they allow ALL radios ? I mean is your SSID1 conecting to 2.4 ghz and your SSID 2 is connecting to 5 GHz?

Re: Wireless clients face latency issues

Scott Fella — Thu, 15 Dec 2011 07:01:41 GMT

So tell me more about the environment. Is it a large amount of users, a small branch office, windows machines, are they connected to the 5ghz or 2.4ghz, do you know if there is interference in that area?

If you map that SSID to the good subnet, check to see if your ping times are still high. This might mean interference in a certain area. The only changes you can make is on the SSID and if you set it to open, then we have to eliminate the wlc SSID vlan as a problem.

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Re: Wireless clients face latency issues

Scott Fella — Thu, 15 Dec 2011 07:07:11 GMT

Here is a good guide and it's something we all try to follow one way or another.

http://www.cisco.com/en/US/products/ps6366/products_tech_note09186a00809d45a2.shtml

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Re: Wireless clients face latency issues

vinodjad1234 — Mon, 19 Dec 2011 07:17:47 GMT

Hi,

If you could share the debug output of < debug client mac address > , it would be helpful to understand for further troubleshooting ....