Internet speed testing websites are often used to help determine if the Internet service provider (ISP) is providing the amount of bandwidth you have subscribed to. If the results of the speed test are unexpected, then there are several steps you can perform to attempt to improve the results.
Try using a different Internet speed testing website
Connect the computer directly to the Internet connection or modem, bypassing all internetworking equipment, and run the Internet speed test again
When an Internet speed test shows unexpected results, the most important step is to try a different speed testing website. Many of these websites use different variables to determine the upload and download speeds. Since they are all different, often you will have drastically exaggerated download or upload speeds between different testers. So, it is recommended to try using multiple sites to obtain an average speed.
Connect Computer Directly to the Internet or Modem
If the computer performing the Internet speed test is going through an ADTRAN unit and/or any other internetworking devices, bypass the units and connect the computer directly into the Internet connection or modem (if the modem is not proving DHCP, you may have to statically assign an IP address to the computer). With the computer directly connected to the Internet, run the Internet speed test to see if the rates improve.
If the throughput rates are as expected with the computer directly connected to the Internet (bypassing the ADTRAN unit), next reconnect the computer to the ADTRAN unit and follow the steps below. If the throughput rates are not as expected with the computer directly connected to the Internet or modem, contact the ISP.
Enable FFE on all interfaces (the fast forwarding engine (FFE) is enabled by default, starting in AOS firmware version R10.4.0.) FFE is enabled on a per-interface basis with the ip ffe command:
(config-eth 0/1)#ip ffe
On the ADTRAN unit, you should verify:
the interfaces do not have any errors
the interfaces are negotiated to the proper speed/duplex (typically, the speed and duplex of Ethernet interfaces are 100 Mbps and full-duplex)
FFE is enabled on all interfaces
To view the status of the interfaces to check for errors and proper speed/duplex settings, issue the show interface command.
0 internal transmit errors, 0 carrier sense errors
0 resets, 0 throttles
You will want to set the ADTRAN to auto on a port so that it will attempt to negotiate the highest speed and duplex with the connected device. However, the keyword is “negotiate,” so it will expect the peer device to give some notification about its speed/duplex as the link comes up. Unfortunately, the peer device will not do this unless it is also set to “auto-negotiate.”
Setting the speed to auto negates any duplex setting on the interface and will allow the port to negotiate its speed and duplex. The only time the duplex setting will be enforced is when the speed is hard-set to something other than auto-negotiate.
If the speed is set to auto and the link negotiated to half-duplex, this usually indicates the connected device is hard-set to a speed and duplex, while the ADTRAN unit is configured for auto. You will want to make sure that both sides are either hard-set or are set to negotiate (auto). Otherwise, the links will not negotiate properly and you will experience performance issues and start seeing errors (late collisions; excessive collisions) on the interface.
The term "auto-negotiate" means that you do not have to hard-set a speed/duplex for the Ethernet link to come up, but it will need to negotiate with the connected device to see which speed/duplex to come up on. For example, say you had ADTRAN1 set to 100/full and ADTRAN2 set to auto-negotiate. ADTRAN1 will bring the interface up at 100/full, but since it is not attempting to negotiate with ADTRAN2 as ADTRAN2 is expecting, ADTRAN2, according to IEEE specifications, will assume the worst case and come up at 100/half.
Some devices can have problems with the IEEE open standard LLDP (which is enabled on AOS interfaces by default), such as cable modems; therefore, ADTRAN recommends disabling LLDP on the interfaces connected to the Internet or modem. To disable LLDP on the interface issue the following command on the interface: