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.
This is how 0° Azimuth and 0° Elevation look like. Plus “squished doughnut” as a bonus to illustrate the coverage pattern 🍩
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°.
Elevation angle is 0° for this orientation.
Cisco DNA Center Azimuth and Elevation configuration
Let’s take this “Back to the basics” question and test things out.
So, we have this 20 MHz capable Windows 11 Wi-Fi client and we want to see what happens when it attempts to join an SSID that uses 80 MHz wide channel. Will it associate? Will it fail?
Here is my client with Intel AX201 adapter forced to only support 20 MHz wide 5 GHz channel.
My AP uses 80 MHz channel width.
Let’s verify the settings from a Mac. Yes, the AP broadcasts 80 MHz wide “lab5” SSID with primary channel 36.
Finally, what happens if the client device is only capable of 20 MHz channel width? As you can see, it will happily join using Primary channel 36.
More capable client devices that support 80 MHz channel width will benefit from the 4 bonded channels and use the 80 MHz channel in its entirety.
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.
6 GHz 2×2 MIMO setup powered by PoE+
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?
I still use C3650 UPOE mGig switch in my lab. Catalysts 9300 and 9400 the best choice these days.UPOE and mGig capable C3650 providing full power to the AP
Final look
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.
Still few things to tidy up and perhaps I could build this into a nice Pelican case
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.
After using FriendlyElec R5S single-board computer as a portable iperf3 server, I decided to also order and test Topton M6 Mini PC. It is more powerful, based on Intel CPU, and runs Windows 11 Pro or Ubuntu. I personally chose Windows (yes, I am brave), mainly because I also wanted to use this device as a Windows Wi-Fi client for other things than iperf3 testing.
Dimensions and case
Compared to the R5S, Topton M6 Mini PC is still portable, but about twice as large. Plastic case wraps the unit, but it is more fragile if you plan to carry it in your backpack or tool bag. There is a built-in fan which is always on. Not a big deal if you use it as an perf3 server, but little inconvenient when it runs on your desk for a longer period of time.
iperf3 performance
Topton M6 has a single onboard 2.5 Gigabit Ethernet port consistently capable of 2.35 Gbps up and down iperf3 throughput with default settings.
Consistent 2.35 Gbps iperf3 throughput
Now, can we make it go faster? Let’s see. We will use USB-A 5 Gigabit Ethernet capable Sabrent adapter. This can either be connected to a USB-A port or USB-C port of the Mini PC. In my tests, I have found that the USB-C port has limited throughput and only tops around 350 Mbps. When I connected the Sabrent 5GbE adapter to USB-C, it only auto negotiated 1 Gbps Full Duxplex.
Use any of the three USB-A 3.1 ports instead to avoid that limitation.
Use USB-A ports, not the USB-C With the USB adapter, we get 2.94 Gbps down and 3.27 Gbps up
With the USB adapter, the whole setup get less portable. But it allows us to achieve 2.94 Gbps down and 3.27 Gbps up from clients perspective. Is it worth the extra spend? If you need to break the 2.35 Gbps barrier of the built-in 2.5 GbE port, this might be a workable solution for you.
Power adapter with an adapter
This Mini PC is quite strict when it comes to its power source. It requires 12V/2A USB-C PD adapter. Unfortunately, your USB-C MacBook or iPad chargers won’t work.
It draws around 7.5 Watts in idle mode.
If you happen to only use this PC in the US, happy days, as the power adapter ships with US plug. If you select UK during the ordering process, you will receive the US power adapter with UK adapter, which adds to its overall size.
My way around this is to use a standard non-USB-PD 12V/2A adapter with 5.5×2.1mm barrel jack connector, and a barrel jack to USB-C adapter. This particular “power brick” has a standard IEC C14 power cable connector, which you can find in any data centre and with the right European, UK, or Australian plug.
Power adapter with barrel jack + barrel jack 5.5×2.1mm to USB-C adapterDetail of barrel jack 5.5×2.1mm to USB-C adapter
Battery power
Simply use a USB-C cable and USB PD battery pack capable of delivering 12V/2A. No surprises there.
Powered by PoE
I prefer powering equipment using PoE over local power bricks. If you are in the same boat, you can power this Mini PC by a PoE splitter.
Please pay close attention to the splitter specs. We want the one with a barrel jack and 12V/2A. Since the Mini PC uses USB-C power connector, we will use a barrel jack 5.5×2.1mm to USB-C adapter. Here is the complete setup. Press the power button and voila!
Under the hood
Most of the components are soldered to the main board with little room for upgrades. I ordered the lowest 8GB DDR4 and 128GB NVMe spec with Windows 11 Pro OEM preinstalled (no actual Windows license included).
I was hoping for the Wi-Fi adapter to be replaceable, but it is not the case. It is Intel AX201 and soldered to the board. Good enough, just not ideal for Wi-Fi professionals. M.2 slot would be ideal.
A quick look at the bottom side of the PCB shows the NVMe drive.
NVMe drive is practically the only replaceable component
Final verdict
Personally, I think this Mini PC has some great potential for certain use cases, but as an iperf3 server, I would rather use the FriendlyElec NanoPi R5S I reviewed here.
If you absolutely need to break the 2.3 Gbps barrier, it can be done with the help of a USB 5 GbE adapter, but it is not very cost effective. The Mini PC cost me £186 including shipping to the UK. The Sabrent 5GbE USB adapter costs around £65.
Finally, it you need top performance, don’t care that much about small form factor, and money is no object, the latest Apple M1 Mac Mini can be configured with built-in 10 GbE.
Wi-Fi standards have developed and also WAN links are fast and reasonably priced these days. When it comes to throughput testing tools like iperf3 servers, 1 Gigabit Ethernet has become a bottleneck. A Wi-Fi 6E client can now easily generate more than 1 Gbps of traffic, but how do we measure it?
To overcome that issue, I am looking for a reasonably priced portable single-board computer, which can push more than 1 Gbps of traffic. It should be powered via USB-C, battery, or PoE powered, and should be portable to fit in my “just in case I need it” tool bag.
FriendlyElec NanoPi R5S
This little FriendlyElec NanoPi R5S single-board computer (SBC) delivers everything I mentioned above. Let’s have a look.
Dimensions and case
It comes with a well designed aluminium case, which also serves as a heatsink. The whole unit is smaller than the smallest iPhone, slightly thicker obviously. It runs silent. There is no built-in fan whatsoever.
Portable? Tick! By the way, did you know that the original WLAN Pi uses NanoPi NEO2?Left to right: WLAN Pi, R5S, Intel-based SBC I am also testing, WLAN Pi Pro
Ports
USB-C power input, two 2.5 GbE, one 1 GbE, HDMI useful troubleshooting or demos, two USB-A 3.0 ports
It has two 2.5 Gigabit Ethernet interfaces (LAN1 and LAN2) and one 1 Gigabit Ethernet interface (WAN). Either of the LAN ports delivers 2.3 Gbps of actual useful iperf3 throughput with default 1500-byte MTU and single stream. I used MacBook with OWC 10 Gigabit Ethernet Thunderbolt 3 Adapter and Cisco WS-C3560CX-8XPD switch.
From client’s perspective that’s 2.27 Gbps down and 2.35 Gbps up
Power
The R5S only draws 4 Watts in idle, and can be powered by any USB-C 5V power source. Your MacBook USB-C charger, iPad/iPhone charger, or USB-C battery pack would do. Alternatively, use a 1 Gigabit Ethernet 5V PoE splitter and PoE power the unit. In my lab with a 2 meter cable, the 1 Gigabit Ethernet PoE splitter actually allowed the R5S auto negotiate stable 2.5 Gbps connection with the switch.
PoE powered
Software
FriedlyElec built and published two operating system SD card images for the R5S – Ubuntu and FriendlyWRT. I tested both, and for my use case FriendlyWRT works best. It has a network-centric and easy to use web UI, has iperf3 preinstalled, and delivers great performance.
Initial setup and tips
R5S ships without any micro SD card, so make sure you have one ready to use. Flash the software image to it using Balena Etcher or similar tool.
Connect the WAN port to a network with existing DHCP server. If you are in the same subnet, simply ping FriendlyWrt.local to get the IP address of the R5S.
Then access the web UI or SSH to the unit, SSH is enabled by default. Change the root password now.
Now, this is important! To achieve maximum throughput, delete the pre-configured bridge interface br0, and configure both multigigabit eth1 (LAN1 port) and eth2 (LAN2 port) as standalone unbridged interfaces. Also, tweak IP address settings to your liking while you are there.
eth1 configured as a standalone interface. Bridge interface removed.
Make iperf3 automatically start by going to System > Startup > Local Startup and add iperf3 -s and hit the Save button.
Change CPU Governor setting to Performance. And CPU Minimum Frequency to the maximum value.
This little single-board computer absolutely deserves its space in my tool bag. For the 2 GB RAM model with case I paid $88 including shipping to the UK. Add a Micro SD card and that’s all you need to get started.
Finally, it you need top performance, don’t care that much about small form factor, and money is no object, the latest Apple M1 Mac Mini can be configured with built-in 10 GbE.
If you have not had a chance to see the new Cisco Catalyst antennas for Catalyst 9130AXE access points, here are a few photos of the C-ANT9103 antenna for your reference.
Optionally, you can order an AP + antenna collocation “pocket”, which the Catalyst 9130AXE slides nicely in. It is aesthetically pleasing it, and all it takes to install the AP and antenna is a single mounting bracket. You don’t have to worry about mounting the access point and antenna separately. This drastically simplifies temporary deployments – just think about Cisco Live for example.
Previous generation with a separate AP bracket and antenna bracketThe new collocated, and aesthetically pleasing, solution with AP installed just behind the antenna
Unboxing
Please always refer to the official Cisco documentation for the latest information and package contents.
If you have followed my hot-swappable series, my goal was to find a solution to swapping multiple outdoor AP + antenna combinations and a variety of AP models on the same tripod. What is the use case? I only wanted to carry a single tripod on the site survey day while still having the flexibility to survey with variety of antennas and different AP models.
Please excuse the DYI approach. I did this during UK’s second COVID-19 lockdown. Shops were closed, access to tools was limited and I had no access to my lab.
How it turned out?
It went surprisingly well this time as I’ve already built a similar adapter for Cisco Meraki MR APs and this time it was even easier. Same as last time, the alu tube slides inside the top tripod tube and we are ready to roll.
The actual steps
I stocked up on M6 x 30 mm bolts, cut the 16 mm aluminium tube to the right length and reused the last bit of decking from a different project.
M6 x 30 mm bolt
I thought I will try making a template, which I then transferred onto the wood. That wasn’t the best idea and it seems to work best when you watch someone using this “trick” on YouTube. Next time I will go for an analog pencil and ruler, lesson learned;-)
That trick did not go as well as I thought :)
The decking is quite thick so I ended up shaving few millimeters off it. And here is the final adapter.
Thanks to Alan Wang, who suggested I use the official articulating pole mount AIR-ACC1530PMK2 and attach it to my “back board”. Obviously azimuth you can adjust by rotating the tripod, and this allow you to change the elevation angle.
