HPE OC20 802.11ac (RW) Access Point performance issues

[matarvai]

We deployed two customer sites with HPE OC20 devices. Both started to have performance issues with wireless with these new OC20 devices. Transfer speeds especially with SMB transfer from Windows servers is horrible. Usually 5GB file transfers takes about 440 seconds. With other AC series devices it takes only 120-150 seconds. We tried upgrading the firmware and same issue. Did not help, when looking at the Windows 10 data transfer screen it only transfer files at 5MB/s speed. We are having this same issue now with 9 OC20 devices that are in two different sites. 

Anyone else having same issues? We have open case number with HPE also with this. We have tried different poe switches also, but same issue remains.

[parnassus]

Were Wireless hosts used to perform your transfer speed test [*] connected to the 2.4 GHz radio band IEEE 802.11n (Maximum theoretical throughput of 300 Mbps, more or less 30 MBps) or to the 5 GHz radio band IEEE 802.11ac (Maximum theoretical throughput of 867 Mbps, more or less 80 MBps)?

To me, an average file transfer speed (if there aren't other bottlenecks elsewhere on the wired side) of just 5 MBps looks like Wireless host is potentially using the IEEE 802.11g radio band at 2.4 GHz (Maximum theoretical throughput of 54 Mbps) or the radio signal is very weak/disturbed if the Wireless host is not in a good line of sight with the Wireless AP used for testing [**].

[*] For sure, better doing various iperf3 client/server tests between a Wireless host and a Wired host...

[**] That's to say that testing (and also planning) a Wireless network could be tricky, you have to consider all variables (Wireless hosts status, wired networking status, how to test, what to test, Wireless APs planning and deployment, avoiding radio interferences and improper APs positioning...it's complex)...clearly if you're testing just one or two APs well positioned, the Wireless host is well connected, Wireless NIC device driver is updated and properly configured, Wireless APs Software is updated, Wired side is OK (no evident bottlenecks)...and you measure bad performances...then there is a real issue.

[matarvai]

Clients are connected at 5Ghz AC to OC20 if we check from client or from OC20. I have attached picture of that. I suggested to HPE ticket the 802.11g radio also, cause speed is so constant. Radio signal is pretty much perfect. We have now connected one OC20 to our lab and laptops are on same table not more then 1 meter away. 

I think this is real issue at the moment. As I said before we have now two sites with multiple OC20 devices and one OC20 in our lab and same issues in everyone. 

[matarvai]

Here is picture attached so you can see that even the OC20 management shows that clients are connected with 5Ghz bandwith.

[parnassus]

Would be interesting to perform the same test you already did on the exact same wireless host using a Linux live distribution as host OS instead of Microsoft Windows 10 (provided that any very recent Linux live distribution should have the latest iwlwifi kernel driver for the Intel® Dual Band Wireless-AC 7265 NIC)...that's to isolate any potential issue caused by (or related to) a specific version of driver provided by Microsoft for its Windows 10 OS (aka: are you using latest Intel provided drivers for Windows 10 - it should be 19.70.0 - instead of Microsoft flavour of the same device driver superimposed via Windows update?).

Start checking from here (or directly here) if you can't test using a Live Linux distribution...

[matarvai]

We have tried with different devices. OK, everyone has been with Windows 10. HP Zbook 14u G4, HP Elitebook 745 G4, Lenovo T470s, HP Zbook 17 G4 and HP Elitebook 840 G4 are the laptops that we have tested. Same results with everyone, currently we don't have any devices with Linux, but we have one Macbook Air that I could try also

[parnassus]

Yeah, to test the Wireless device behaviour under Linux (once you checked the Windows device driver side) you don't need to install anything on your laptops...a Live Linux distribution - as example you can try Fedora 26 Desktop Live with XFCE here - doesn't require to install anything, you can easily try it just booting from a DVD or USB stick (follow instructions on how to create a bootable DVD/USB from downloaded images).

[matarvai]

Just tried with live Linux, same problem. Strange thing is that speed doubled, now it is 10MB/sec, but still much slower than other access points. No fluctuation on speed, pretty much constant 10MB/sec. Also again client and OC20 shows that live client is connected with 5Ghz and 802.11 AC

[parnassus]

Pretty interesting, considering that doubling the 5 MBps value to 10 MBps means a gain of 100%...not the result you expect but still remarkable (Consider also that you can try a large amount of iwlwifi related optimizations using Linux...just as example, think about the WiFi/Bluetooth operations coexistence).

Probably there is something related to IEEE 802.11ac Channel Bandwidth settings on the OC20 (as example a Channel width of 20 MHz - with just one Spatial Stream SS involved - seems to provide, depending on MCS Index 0-9, bit rates ranging from 7.2 to 96.3 Mbps at 5 GHz...pretty compatible with a throughput of only 10 MBps).

Would be interesting to deep dive into Linux CLI [*] to grab all information about iwlwifi and your Intel 7265 AC adapter [*]...but, probably, also HPE should give you some troubleshooting support on OC20 side.

[*] starting with a:

$ dmesg |grep iwlwifi

and going on checking available microcode (17 should be the latest for 7265):

$ ls -ltr /lib/firmware/|grep 7265

up to showing with iw command the connection status:

$ iw dev wirelessinterfacename link

 where wirelessinterfacename should be changed with the actual Wireless NIC name given by Linux on your test host (you should see a line on the output of the first dmesg command about a "wirelessinterfacename: renamed from wlan0", that's the actual Wireless interface name...the wlan0 was the old name provided by the previous NIC naming system).

[Steve12]

If you still have the issue with performance, getting a look at the output of this command in Windows command line may help:

> netsh wlan show interfaces

It will give you details on the channel used and the connection rates.