Solved: Slow Download Speed on AC-8260 (Possible Fragmentation?)

CJohn15 · ‎08-02-2017

Good Evening,

I'm one of the wireless network administrators at our university and one of our employees brought to our attention an issue he was running into pretty consistently. Performing a speedtest shows that his download speeds are in the range of .04Mbps but his upload speeds are perfectly normal between 50Mbps to 60Mbps - he located a previous post that has since been resolved - /thread/115425 https://communities.intel.com/thread/115425 - but it was resolved with the administrator making an infrastructure wide change to the MSS (Maximum Segment Size) value. The behavior we're seeing is very similar to a fragmentation issue we saw at remote offices due to double encapuslation (IPSEC/GRE) which caused fragmentation on our Aruba Controllers - resolved by setting MTU to 1200 for these remote offices - but this is slightly different in the sense that this is on a campus AP where our MTU is set to 1500.

Would like assistance in verifying this is the issue we're running into and a method of resolving this on the client-side.

Thank you and have a good day!

idata · ‎08-03-2017

Hello GuardianDroid,

We understand one of your WiFi clients is getting low download speeds, we received a few reports like this, specially after Windows® 10 Creators update. Here are some possible solutions/workarounds to consider from the computer side:

1. If this is on Windows® 10, make sure the OS is fully updated and using Microsoft KB4022716. This is mentioned in the following Advisory: /thread/115898 Troubleshoot Low Wi-Fi Throughput on Windows 10 Creators Update (Version 1703)

2. Also, make sure the system is using https://downloadcenter.intel.com/product/86068/Intel-Dual-Band-Wireless-AC-8260 Intel® PROSet/Wireless Software and Drivers [19.70.0], along with the https://www.intel.com/content/www/us/en/support/network-and-i-o/wireless-networking/000005544.html Recommended Settings for 802.11n Connectivity.

3. You can try lowering the MTU from the client side, as mentioned in the thread: /message/480862# 480862 Intel dual band 7260AC for desktop hangs on Windows 10 creator edition with IPv6 enabled

Let us know if any of these actions help, or in case you require further assistance.

Regards,

Jonathan B.

View solution in original post

idata · ‎08-03-2017

Hello GuardianDroid,

We understand one of your WiFi clients is getting low download speeds, we received a few reports like this, specially after Windows® 10 Creators update. Here are some possible solutions/workarounds to consider from the computer side:

1. If this is on Windows® 10, make sure the OS is fully updated and using Microsoft KB4022716. This is mentioned in the following Advisory: /thread/115898 Troubleshoot Low Wi-Fi Throughput on Windows 10 Creators Update (Version 1703)

2. Also, make sure the system is using https://downloadcenter.intel.com/product/86068/Intel-Dual-Band-Wireless-AC-8260 Intel® PROSet/Wireless Software and Drivers [19.70.0], along with the https://www.intel.com/content/www/us/en/support/network-and-i-o/wireless-networking/000005544.html Recommended Settings for 802.11n Connectivity.

3. You can try lowering the MTU from the client side, as mentioned in the thread: /message/480862# 480862 Intel dual band 7260AC for desktop hangs on Windows 10 creator edition with IPv6 enabled

Let us know if any of these actions help, or in case you require further assistance.

Regards,

Jonathan B.

idata · ‎08-10-2017

Hello GuardianDroid,

Please let us know if there was any change in the behavior, of in case you require further assistance.

Regards,

Jonathan B.

CJohn15 · ‎08-12-2017

Good Morning Jonathan,

Thank you for your help. I actually received a response from the employee yesterday and their issue has been resolved thanks to your suggestion. Download speeds were restored from .01Mbps to 117.4Mbps based on speed tests.

Suggestion 3 - Lowering the MTU from the client side to 1400 per your suggested thread resolved the issue - /message/480862# 480862 Intel dual band 7260AC for desktop hangs on Windows 10 creator edition with IPv6 enabled

Prior to adjusting the MTU - the employee already had KB4022716 (Suggestion 1) installed as well as the latest version of the Intel Driver [19.70.0] (Suggestion 2) - and still had the issue.
We have other laptops with the AC-8260 driver that didn't have issues - although they weren't running the Windows 10 Creators Update (1703).
Lowering the MTU was the solution (or final piece).

Windows 10 Creators Update (1703) won't be deployed in our environment for several months. But I'll definitely be looking into this issue further and following other discussions (as well as that RSC feature) - interesting how wide-spread it is - https://social.technet.microsoft.com/Forums/windows/en-US/27dd19ab-78a2-42fc-accb-34bd949a30a7/windows-10-creators-update-causing-very-slow-wifi?forum=win10itpronetworking&ranMID=24542&ranEAID=TnL5HPStwNw&ranSiteID=TnL5HPStwNw-06dXZ7vmar_RSk_HMVcgkw&tduid=(b0fe3988aaf7e5908d9b66efe5c7d629)(256380)(2459594)(TnL5HPStwNw-06dXZ7vmar_RSk_HMVcgkw)() Windows 10 Creators Update Causing Very Slow WiFi - as well as adjusting the MSS-Value to 1300 for Cisco in those discussions.

Thank you for your assistance Jonathan. I'll open a new thread if need further assistance once I dive into this issue further.

idata · ‎08-14-2017

Hello GuardianDroid,

We are glad to know the issue was solved with our recommendations. Feel free to contact us if you have any further questions.

Regards,

Jonathan B.