Switching - Configure Bandwidth Control [Rate Limit]

This example shows administrators how to configure bandwidth control to manage traffic rates.
We can limit either incoming traffic, outgoing traffic or both.
In this example, we use two computers: FTP Client (PC) and FTP Server (FTPServer).
The PC will either be uploading files or downloading files from the FTP Server.

Configure bandwidth control to limit the traffic rate

Note:
All network IP addresses and subnet masks are used as examples in this article. Please replace them with your actual network IP addresses and subnet masks. This example was tested using an XGS4600-32 on firmware v4.50.

1) Configure Bandwidth Control

1. Enter the web GUI and go to

SWITCHING > QoS > Bandwidth Control

2. Check the “Active” box. Key in the rates in Ingress Rate (upload limit) = 10240 kbps and Egress Rate (download limit) = 20480 kbps.

 Remember to check the port “Active” boxes as well. Click “Apply” at the end.

3. Save the Configuration

Test the Result

1. Use the PC to upload a file to the FTP Server. The transfer rate should be more or less 1.25 MB/s (10240 Kbit/s).
   
   
   
2. Use the PC to download a file from the FTP Server. The transfer rate should be more or less 2.5 MB/s (20480 Kbit/s).
   

If you're having problems

Turn on Flow Control on both the Switch & PC

A known issue we have experienced, is that TCP throughput on some devices might be unstable and unreliable. This is due to that ingress Bandwidth management (BWM) on some devices (e.g. Windows computers with less efficient network cards) is performing poorly when configuring bandwidth control (rate limiting) and could cause an unexpected result. When bandwidth management is implemented, turning on flow control increases ingress throughput because the transmitting PCs will not overflow the window size and cause packet loss. 

Flow control works by sending pause signals to the sending port when the receiving port's (on the switch) buffer memory is full, which regulates traffic to match the bandwidth control settings of the receiving port. Flow control needs to be enabled on both sides in order for it to have an effect. However, the good thing is that most network cards in PCs  should have flow control enabled by default, which is why you can obtain satisfactory results by only enabling flow control on the switch ports. 

Configure Flow Control by navigating to:

PORT > Port Setup

2) Configure Bandwidth Control on old GUI

1. Enter the web GUI and go to

Menu > Advanced Application > Bandwidth Control

2. Check the “Active” box. Key in the rates in Ingress Rate (upload limit) = 10240 kbps and Egress Rate (download limit) = 20480 kbps.

 Remember to check the port “Active” boxes as well. Click “Apply” at the end.

Test the Result

1. Use the PC to upload a file to the FTP Server. The transfer rate should be more or less 1.25 MB/s (10240 Kbit/s).
   
   
   
2. Use the PC to download a file from the FTP Server. The transfer rate should be more or less 2.5 MB/s (20480 Kbit/s).
   

If you're having problems

Turn on Flow Control on both the Switch & PC

A known issue we have experienced, is that TCP throughput on some devices might be unstable and unreliable. This is due to that ingress Bandwidth management (BWM) on some devices (e.g. Windows computers with less efficient network cards) is performing poorly when configuring bandwidth control (rate limiting) and could cause an unexpected result. When bandwidth management is implemented, turning on flow control increases ingress throughput because the transmitting PCs will not overflow the window size and cause packet loss. 

Flow control works by sending pause signals to the sending port when the receiving port's (on the switch) buffer memory is full, which regulates traffic to match the bandwidth control settings of the receiving port. Flow control needs to be enabled on both sides in order for it to have an effect. However, the good thing is that most network cards in PCs  should have flow control enabled by default, which is why you can obtain satisfactory results by only enabling flow control on the switch ports. 

Configure Flow Control by navigating to "Basic Setting -> Port Setting":