Cisco Wireless controller 2504 and AP 2700 series Latency Issue

[Muhammad Amin Zia]

Hello Cisco experts. I have Cisco WLAN 2504 and 2700 series AP. We have around 800 users and we are using 20 AP's. All users are using a single SSID . Issue is when 50-80 users are connected to WLAN its latency from end user to WLAN controller becomes 45-65ms and when users reaches to 300 its latency will cross 1000-2000ms and intermittent drops. Currently 9 Users are connected and its latency is 2ms -4ms. Please highlight the possible issues. Thank you

[Leo Laohoo]

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@Muhammad Amin Zia wrote:

Issue is when 50-80 users are connected to WLAN its latency from end user to WLAN controller becomes 45-65ms and when users reaches to 300 its latency will cross 1000-2000ms and intermittent drops.

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Check the link status between the WLC and the switch. 

Maybe the link between the WLC and the switch is 100 Mbps only?

[Muhammad Amin Zia]

Thank you for your reply but its gig . Any other reasons for the subjected issue.

[Leo Laohoo]

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@Muhammad Amin Zia wrote:
Thank you for your reply but its gig . 

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If the switch is Cisco, then post the complete output to the command "sh interface <PORT>".

[Muhammad Amin Zia]

GigabitEthernet2/0/3 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 2c44.3df7.ba83 (bia 2c44.3df7.ba83)
Description: WLC Controller
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:35, output 00:00:01, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 16826
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 1513000 bits/sec, 280 packets/sec
5 minute output rate 1503000 bits/sec, 255 packets/sec
8442100358 packets input, 5538889975211 bytes, 0 no buffer
Received 14494245 broadcasts (4723452 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 4723452 multicast, 0 pause input
0 input packets with dribble condition detected
6645671306 packets output, 5355844332680 bytes, 0 underruns
0 output errors, 0 collisions, 1 interface resets
0 unknown protocol drops
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

[paul driver]

Hello

the output packet drops in relation to the total egress packets is minimal also these interfaces stats could be misleading as the counters have never been cleared so this may be historical your are seeing 

res

paul

[Muhammad Amin Zia]

I have cleared the counters yesterday and current stats are pasted below for your reference.

GigabitEthernet2/0/3 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 2c44.3df7.ba83 (bia 2c44.3df7.ba83)
Description: WLC Controller
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:43, output 00:00:00, output hang never
Last clearing of "show interface" counters 23:19:04
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 315
Queueing strategy: fifo
Output queue: 0/40 (size/max)
30 second input rate 346000 bits/sec, 99 packets/sec
30 second output rate 381000 bits/sec, 117 packets/sec
287021595 packets input, 181853626056 bytes, 0 no buffer
Received 680276 broadcasts (202734 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 202734 multicast, 0 pause input
0 input packets with dribble condition detected
238876534 packets output, 177053847722 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 unknown protocol drops
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

[paul driver]

Hello

800+ users - single ssid -20 aps

what does wlc logs show?

Is this specific to a certain radio channel 

Are you working on both ism bands and if so is this latency occurring on both or just the one

res

paul

[Muhammad Amin Zia]

Can you tell me how to check logs and i am using only 2.4GHz band and its showing latency on it.