2.4GHZ clients very slow speeds with AP3600

[stephendrkw]

5508 WLC (7.5.102)

AP36021

We currently have a test WiFi SSID setup that uses basic mac filtering on our WLC's

WLAN is configured with WPA and WPA2 L2 Security with WPA Policy and WPA2 Encryption.

For some reason we seem to be getting very slow speeds on clients with 2.4GHZ

for example speedtest.net I get 70mg upload and 65mg download on 5GHZ devices and about 1-3mg download and 1mg upload for 2.4GZ devices!

AP36021 are dual band with 4 channels (2 x 2.4Ghz and 2 x 5Ghz)

fyi - There are no dropped packets on the client stats via Prime mgmt that use 2.4GHZ

Any ideas here?

[stephendrkw]

sh int gi4/32
GigabitEthernet4/32 is up, line protocol is up (connected)
  Hardware is C6k 1000Mb 802.3, address is 0015.c634.4fbf (bia 0015.c634.4fbf)
  Description: ukgre05-051-a36
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 10/100/1000BaseT
  input flow-control is off, output flow-control is off
  Clock mode is auto
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:02, output 00:00:35, output hang never
  Last clearing of "show interface" counters 41w6d
  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  30 second input rate 1000 bits/sec, 1 packets/sec
  30 second output rate 0 bits/sec, 0 packets/sec
     124898544 packets input, 27675117366 bytes, 0 no buffer
     Received 1317350 broadcasts (892533 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     193076170 packets output, 112790254666 bytes, 0 underruns
     0 output errors, 0 collisions, 1 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

[Rasika Nayanajith]

Hi

As you can see, your AP connected port is negotiated to 100Mbps. Ideally it should be negotiated to 1Gbps. Just use "speed auto" without any values, then port will be negotiated to 1Gbps.

This is important specially your AP is 3600 which can provide upto 450Mbps throughput. Depend on the client number of spatial stream you can get below data rates. In 2.4GHZ BW is 20MHz you can go upto 195Mbps (with GI 800ns) max with 3 SS client.

First makesure you have corrected that issue. If you get "show client detail " output it will show you at what MCS data rate client get connected.

HTH

Rasika

**** Pls rate all useful responses ****

[stephendrkw]

Hi Rasika,

port now changed

sh int status | i 4/32

Gi4/32       cisco-a36    connected    30         a-full a-1000 10/100/1000BaseT

I suppose the link could be saturated and that's a very basic error on my part!

The persons that are taking part in my tests with 2.4GHZ devices are away today, I'll send feedback Monday with speed results.

Thanks.

[Ali Aqrabawi]

can you post show client details

[mdemarais]

I know this is an old thread, but was there any feedback on the fix for this issue - we have very similar issue?