05-22-2019 08:44 PM - edited 07-05-2021 10:27 AM
Hi Guys,
I have a case from my customer about transferring data from server and clients using Cisco AP 1852 and 2802. We need the transfer rate above 10MB/s. After we testing so many times using many methods (like change the data rates on configuration radio on our wireless controller 2504) the results never reach above 10MB/s. Please check the documents that contain the results in the attachments. What I want to ask is:
What is the bandwidth sharing mechanism for more than one client to transfer data?
Is there a best practice configure to maximize tuning throughput / speed of copying client data using Cisco access points?
Is there a datasheet for the maximum transfer rate of the Cisco access point
What are the advantages of Cisco Access Points compared to other brands (such as Aruba, Allied Telesis, etc.)?
Sorry if I'm asking too much. I really need a descend answer also some advice about this case. Please help me.
Thank you.
05-23-2019 03:19 AM
05-23-2019 04:01 AM
We have NIC that supports 5GHz too as you can see in the attachment but still, the data rate is on 10MB/s average.
05-23-2019 01:47 PM
05-23-2019 05:43 AM
What is the bandwidth sharing mechanism for more than one client to transfer data?
"wireless is half duplex" which is first thing you need to remember. That mean any wireless device cannot transmit & receive at the same time. That mean lot of waiting time by clients.
Wireless operation is based on CSMA/CA (Carrier Sense Multiple Access- Collision Avoidance). So whole idea is to avoid any possible collisions on wireless cell when AP & clients operates. Therefore, if you want to test best case scenario, you need to have a single client in a wireless cell & then you can test wireless performance with wired side iperf.
Also remember you need to have management & control traffic other than data traffic. More clients in the cell & more SSIDs in given AP, you will wast lot of valuable air time for control & management traffic. Therefore actual data throughput is much less than the data rates given standard support.
For example if you got 802.11n 3x3:3SS AP, then maximum capacity is 450Mbps, Due to half duplex nature you can get ~200Mpbs (less than 50%) with a single client operate in the cell. That also depend on client capability & assuming given client support 802.11n,40MHz, 3SS (check this site for client capabilities). When you add more clients that bandwidth is shared by all of them & increase of management & control frames further reduces client throughput.
In your scenario, you seen 10MB/s, which is 80Mpbs throughput, which is a better value than you think (don't compare what you get with wire)
Is there a datasheet for the maximum transfer rate of the Cisco access point
Here is 2802 AP datasheet
Below MCS index will show all possible data rates with 802.11n & 802.11ac
Is there a best practice configure to maximize tuning throughput / speed of copying client data using Cisco access points?
To support above MCS data rates, WLAN has to configured with WPA2 (PSK or 802.1X), unless it is open SSID.
Also you will notice those MCS rates varies depend on three parameters given below.
1. Channel width (20MHz, 40MHz , 80MHz)
2. Spatial Streams (depend on client hardware)
3. Guard Interval (Short or long)
Also having good RSSI/SNR will help to achieve higher modulations (greater than 25dB)
In summary, you notice best result can be achieved with 5 GHz, when channel bonding (40, 80MHz) depend on how many APs deployed in given area (more channel you bond, less number of APs you can have near by). When you adding more wireless clients throughput is decreasing.
2.4 GHz performance is well below 5.0GHz performance. This is normal behavior as you will see much interference in 2.4GHz, resulting clients to wait longer prior to get a opportunity to transmit.
Hope this gives some explanation what you experiencing.
HTH
Rasika
*** Pls rate all useful responses ***
05-27-2019 01:28 AM
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