Jiri is passionate about mobility ranging from Wi-Fi to folding bikes;-) He is a Wi-Fi Technical Solutions Architect at Cisco UK, proud member of the Cisco Live Network Operations Center deployment team, and WLAN Pi development team. If he is not working, he is most likely riding his Brompton bike.
This question comes up and every now and then. So, let’s put it to bed.
If you have a ceiling mounted internal antenna AP (with built-in antennas), or external antenna AP with dipole antennas (AIR-ANT2524D), or with short dipole antennas (AIR-ANT2535SD), here are the correct Azimuth and Elevation angle settings.
Azimuth angle does not matter in this case (it does for directional antennas), because these antennas have the same pattern regardless of how you rotate them clockwise or counterclockwise. Simply use the default value of 0°.
My Catalyst 9800-CL controller is hosted on a cloud, so I don’t need any hardware for that. Finally, my Catalyst 9136 Wi-Fi 6E AP is powered by a Catalyst 3560CX 10 Gigabit Ethernet multigigabit switch.
Catalyst 9136 is Cisco’s premium AP with all the bells and whistles including hexa-radio architecture and built-in environmental sensors for smart building use cases. It requires an 802.3bt/UPOE power source to enable 6 GHz radio in full performance 4×4 MIMO mode. The switch I use supports 802.3at/PoE+, which is great, but 6 GHz radio downshifts to 2×2. And that’s where an 802.3bt power injector comes to the rescue.
Since the Cisco injector isn’t widely available yet, I decided to test this Zyxel one. It provides 802.3bt power and allows the AP to run in full power and full 4×4 6 GHz radio mode with no compromise.
Do I like power injectors in production?
Absolutely not! Ideally you should design for 802.3bt/UPOE switches to power all your new APs via PoE.
It allows you to:
easily, centrally and remotely monitor how much power the APs use
enable/disable power on a port to bounce an AP
leverage redundant Platinum-rated power supplies for the AC to DC power conversion
manage the solution with ease – just think how difficult it is to manage more than 1 power injector, the number of AC power sockets, and what happens when someone disconnects the injector?
Carrying a full-size switch is not really an option for me, because small form factor is my main goal. So a power injector works best for me. But if I could I would love to use a compact 802.3bt switch.
Are you wondering if the PoE splitter connected to my iperf3 server (the little black box with 3 Ethernet interfaces) actually negotiated 2.5 Gbps Full duplex with the switch? Yes, it did. But keep in mind that the PoE splitter is technically only rated for 1 GbE. So use as short patch cable as possible and ideally CAT6.
Or you can consider an add-on 10 Gigabit Ethernet Thunderbolt 3 adapter for your current Mac.
We will focus on the latter today.
Thunderbolt 3, not USB
While the USB-C connector might temp you to connect these adapters to a standard USB port, these adapters don’t support USB protocol. They use Thunderbolt 3 and they happen to use the same USB-C connector as USB. That’s the only thing USB and Thunderbolt have in common. Before you order one of these adapters, double-check that your computer supports Thunderbolt 3. That should be most new MacBooks, Mac Minis, Intel NUCs and similar platforms.
Which 10 GbE adapter shall I buy?
I tested two of these Thunderbolt 10 GbE adapters. One made by Sabrent, and the other by OWC. They both look alike, both perform very well, both get quite warm, and bothwork out of the box on macOS. Yes, no driver installation required on your part on macOS! 🎉
Mainly because of the loose Sabrent cable issue explained below, I recommend the OWCadapter. It comes with great documentation, and even the Thunderbolt cable itself is thicker and feels premium.
From throughput perspective, I personally tested it up to 3 Gbps down and 3.3 Gbps up using iperf3 with default settings. The limitation is on my part, I just don’t have another 10 GbE computer I could test against.
I’ve seen reports of:
between 7 Gbps and 8.74 Gbps uplink speeds with default iperf3 settings
9.5 Gbps uplink iperf3 speeds with Jumbo frames enabled
The OWC adapter also supports VLAN tagging. Here is my Trunk port with Native VLAN 129:
Let’s tag all traffic with VLAN 130:
Verify that we are indeed in VLAN 130:
If you only want to use VLAN 130 (without touching the Native VLAN 129), you can disable the adapter itself. VLAN 130 virtual interface will stay up and forward traffic.
Sabrent Thunderbolt 3 to 10 Gbps Ethernet Adapter TH-S3EA
I won’t go into the detail, but my main challenge with the Sabrent adapter was its loose Thunderbolt cable. The connection between the USB-C socket on the adapter and the USB-C connector on the Thunderbolt cable is very loose and practically pulls out just by the tension of the cable itself. It might have been just my unit, but I can’t recommend it.
What about Windows and Linux support?
I tested the Sabrent adapter on Windows 10. It required a Sabrent driver installation and then it worked just fine. I would assume the same for the OWC.
I don’t have a Linux computer with a Thunderbolt port, so I can’t share anything on that front.
You might remember me saying something about designing a 3D printed WLAN Pi tripod mount. Yes, that was the plan… until I found a much better solution, which I had already owned.
Why tripod mounted? Well, occasionally I work on an outdoor Wi-Fi project. WLAN Pi can be a really useful for throughput testing, or it can share your phone’s cellular internet connectivity with your access point. This is really useful in cloud-managed surveys, labs, and projects.
Tern RidePocket Handlebar Bag
I present to you this small, well designed, and weatherproof Tern RidePocket bag. It is a fantastic bicycle bag, and as good bag for your WLAN Pi. You can purchase one in many countries around the globe and made by a big bike company, which is here to stay.
If you wanted to, you can battery power your Pi. Just add a battery pack of your choice.
Outdoor surveys involve all kinds of weather, and that’s where this rain cover becomes really useful.
What makes it work better than other or cheaper bags? It mounts securely, and does not slide down the tripod thanks to its strap coated with a layer of anti-slip rubber material.
If you prefer a Raspberry Pi 4, or WLAN Pi Community Edition based on Raspberry Pi 4, it fits in this bag too including a PoE splitter with little effort.
Lenlun Bike bag set
Do you need to interact with your WLAN Pi while it is mounted? No problem. I’ve tested a handful of other bags and Lenlun Bike bag set is the best fit. It allows you to see the display and press buttons while it protects everything stored inside.
Finally, after you are done working, these bags can happily carry your keys, phone, battery pack, and wallet.
Sabrent NT-SS5G is a 5 GbE USB adapter, which allows you to achieve higher throughput than 2.5 GbE adapters, and break the 2.35 Gbps barrier. It works great on Windows. If you are a macOS or Linux user, I recommend you consider other options like this instead.
The adapter itself is larger than 2.5 GbE adapters, it uses AQC111U chip, and ships with short 2 detachable USB-A and USB-C cables. USB-C port on its back connects the adapter to your computer. A metal shell protects it, serves as a heatsink, and also adds to its weight.
In adapter options, you can actually configure quite a few things including Jumbo frame support. Note that these are fixed values.
I can’t recommend this adapter for macOS users. It forces you to disable macOS System Integrity Protection (csrutil), otherwise it won’t work. It might be okay for a proof of concept or lab setup, but I would hesitate from using it in production.
This is how to install the driver if you were interested:
Install the driver using the pkg file provided by Sabrent. It installs a Kernel Extension (kext), which drives this adapter.
Enable the extension by going to System Preferences > Security & Privacy > enable the extension > Reboot.
After reboot, unplug the adapter and plug it back in.
It should work as long as you leave the System Integrity Protection disabled.
From throughput perspective, it saw download speeds of 3.30 Gbps, and upload of 3.45 Gbps. This was with default iperf3 settings, standard 1500-byte MTU and one stream. Great results considering that this adapter’s USB interface maximum theoretical throughput is 5 Gbps.
In my view, you might be better off buying a 2.5 GbE adapter, which can push 2.35 Gbps up and down consistently and with no driver installation needed. I tested one here. Alternatively, a 10GbE Thunderbolt Ethernet adapter is even faster choice, but more costly, and larger form factor. Or, if your other half approves, treat yourself to an M1 Mac Mini with built-in 10 GbE 😉
I tested this adapter on 64-bit Raspberry Pi OS running on Raspberry Pi 4. Although the default driver distributed in Linux Kernel 5.15 works, it doesn’t even deliver symmetric 1 Gbps.
Let’s download the latest driver from Sabrent’s website. Unfortunately that doesn’t seem to be able to compile for 64-bit OS. I tried compiling on 32-bit Raspberry OS, to no avail. If you have any ideas, please do let me know.
Plugable makes this inexpensive 2.5 Gigabit Ethernet USBC-E2500 adapter. It is based on Realtek RTL8156B chip. On Windows and macOS it works out of the box. If you want to use it on a Linux machine like WLAN Pi Pro or Raspberry Pi 4, expect some troubles along the way, but good performance when you get there.
When they say “update the driver using Windows Update first”, they mean it. Windows 11 will recognise the adapter and you can start using it, but the default driver distributed with Windows 11 significantly reduces this adapter’s performance.
Now, let’s use Windows Update to download the latest driver.
As you can see, download throughput (from iperf3 server to iperf3 client) has dramatically improved.
Although the box suggests Jumbo frame support, Windows driver settings don’t give me any option to edit the MTU size. So, I assume Jumbo frames are not supported.
On macOS, this adapter works out of the box with no additional driver installation required. That’s a very nice surprise. And performance is great.
Auto-negotiation worked just fine. If you want to configure speed or MTU manually, you can, but Jumbo frames are not supported on macOS either.
Now the bad news. If you are considering to use this adapter on a Linux machine, the default driver cdc_ncm is a trouble as it only supports 2.5 Gbps Half duplex. Setting Full duplex manually using ethtool command doesn’t work either.
As you might expect, with the default driver and Half duplex, throughput is very poor.
On WLAN Pi Pro and Raspberry Pi 4 running 5.15 Linux Kernel I managed to fix the duplex issue by the steps listed below. But I hit new auto-negotiation issue between the Plugable adapter and Cisco Catalyst WS-C3560CX-8XPD switch. It took the adapter to eventually negotiate 2.5 Gbps Full duplex around 15 minutes of constantly flapping the interface. Forcing speed and duplex on the Plugable adapter by ethtool did not work. Certainly not ideal, and definitely worth testing before you commit to the Plugable adapter. With other multigigabit adapters, the Plugable had no negotiation issues.
How to force Linux to use the right driver
To enable Full duplex capability, we need to tell Linux to use Realtek r8156 driver instead of the default cdc-ncm.
Has your bike suddenly lost its Wi-Fi connection after a Peloton software update? Is it saying “Device not connected to internet”?
Here is why and how to fix it before it hopefully gets fixed in one of the upcoming Peloton software updates.
Peloton bikes use Android operating system, and they have recently upgraded to Android 10. Unfortunately, this version has compatibility issues with Cisco Wi-Fi access points and Adaptive Fast Transition feature, which is enabled by default.
To resolve the issue, simply set Fast Transition to Enabled.
Connect to your Wireless LAN Controller, go to Configuration > Tags & Profiles > WLANs > select the network > click Edit > Security > Layer2 > Fast Transition > Enabled > Update & Apply To Device. Now, test that your bike can connect, and test few other devices to make sure everything is working as expected. Then click the floppy disk icon to save this new configuration.