[Network|UniFi] UniFi 6 Switch 24 coming soon to Early access store | 2.5G Base-T Ports

This will be a replacement/upgrade versions of USW-Pro-24-PoE, which sadly I just purchased a little over a month ago. So let’s compare to the switch as well as its non-PoE version.

The key difference here is 2.5G PoE+ ports. Why did’t they include 5G-Base T support? Is 1 Gbps not enough? Do we really need the speed? Let’s take a closer look.

How fast can Wi-Fi 6 get?

Most of this blog reader by now should know manufacture’s advertised Wi-Fi speed is just a theoretical max speed and no where near real world speed. In contrast, wired speed is the real speed. So is 2.5 Gbps enough to support Wi-Fi 6 speed? Do we need 2.5 Gbps? Is it enough?

We should look at the bottom row with Wifi 6 4×4 because we could in theory have two 2×2 clients accessing the AP simultaneously for the maximum throughput.

1 Gbps is no longer enough

With it, you can see even in-efficient Wi-Fi 6 system with efficiency factor of 50%, the throughput flowing to the AP will go over 1 Gbps. So current 1 Gbps ethernet connection speed is not enough and it can become a bottleneck.

What about 160 MHz channel width?

Based on the table above, the 2.5 Gbps wired speed seems plenty. But can we potentially go over that number? If you have read the max theoretical speed article, you know Wi-Fi 6 supports 160 MHz channel width. With the twice channel width, one can get twice the speed. So with the 70% efficient system supporting 4×4 MIMO at 160 MHz channel width, one can expect 1680*2 = over 3.3 Gbps throughput. This makes 2.5 Gbps wired link to be enough.

However, UniFi’s current generation AP’s i.e. UAP HD series supports 160 MHz channel width only at 2×2 MIMO configuration rather than 4×4. So it can increase single device throughput on the supported client devices but net throughput in the AP remains the same. I am fairly certain this is true for Wi-Fi 6 AP series as well because all the revealed APs to this date are labeled for 2.4 Gbps throughput on their 5 GHz band rather than 4.8 Gbps.

2.4 GHz Wi-Fi 6 band

With dual band AP, the 2.4 and 5 GHz traffics can occur simultaneously. Currently, all the revealed Wi-Fi 6 UniFi APs are sticking with Wi-Fi 5 technology, which is inferred based on the spec of 300 Mbps throughput. However, Wi-Fi 6 2.4 GHz can support up to 1148 Mbps PHY with 4×4 MIMO. This translates to up to 800 Mbps throughput in 2.4 GHz band. Therefore, if UniFi ever decides to support 4×4 Wi-Fi 6 compatible 2.4 GHz band on one of their AP, together, the dual band AP could reach up to 800+1680 = 2480 Mbps throughput. This perfectly matches to 2.5 Gbps ethernet speed.

if UniFi ever decides to support 4×4 Wi-Fi 6 compatible 2.4 GHz band on one of their AP, together, the dual band AP could reach up to 800+1680 = 2480 Mbps throughput.

Do we need new ethernet cable? 

NBASE-T™ technology defines a new type of Ethernet signaling that boosts the speed of installed based twisted-pair cabling well beyond the cable’s designed limit of 1 Gigabit per second (Gbps) for distances up to 100 meters.

Capable of reaching 2.5 and 5 Gbps using the large installed base of Cat5e and Cat6 cabling, NBASE-T solutions enable users to accelerate their networks in the most cost-effective, least disruptive manner.

https://archive.nbaset.ethernetalliance.org/technology/what-is-nbase-t/

So the answer is “No.” As long as your Ethernet wiring is cat 5e i.e. gigabit speed supporting, your wiring is ready for 2.5 Gbps upgrade.

As long as your Ethernet wiring is cat 5e i.e. gigabit speed supporting, your wiring is ready for 2.5 Gbps upgrade.

No IEEE 802.3bt?

Looking at the specs, Pro-24-POE supports bt POE++ but U6 Switch does not list that. What does this mean?

Looking at ways of increasing the amount of power transmitted, IEEE has defined IEEE 802.3bt 4PPoEin September 2018.^[11] The standard introduces two additional power types: up to 55 W (Type 3) and up to 90-100 W (Type 4). Each pair of twisted pairs needs to handle a current of up to 600 mA (Type 3) or 960 mA (Type 4).

https://en.wikipedia.org/wiki/Power_over_Ethernet

So they may not have high voltage PoE. May be that’s not a big deal to most of us as none of AP will ever require that much of voltage.

What is more interesting to me is the following statement from the same Wikipedia page as above.

Additionally, support for 2.5GBASE-T, 5GBASE-T and 10GBASE-T is included.^[13]

https://en.wikipedia.org/wiki/Power_over_Ethernet

Does this mean USW-24-Pro Gen 2’s eight BT capable ports will run not only 2.5 but 5G and 10G?

Well, I know the answer. Sadly, “No.” There is no way the company will make such update even if they were capable of because that would make this switch suddenly far better than its $200 more expensive flagship switch. But I thought this was interesting.

Where is the AP?

At time of this writing, UniFi 6 Lite and UniFi 6 in-Wall are available on early access store for the purchase (though likely sold out). UniFi 6 Mesh is on its way. However, as far as we know, none of currently revealed WiFi 6 AP specifically states to support 2.5 Gbps. If these APs use 1 Gbps ethernet port, they will be the bottleneck and speed will be limited to 1 Gbps. If you are thinking about head starting Wi-Fi 6 UniFi, be very careful about this fact.

none of currently revealed WiFi 6 AP specifically states to support 2.5 Gbps. If these APs use 1 Gbps ethernet port, they will be the bottleneck and speed will be limited to 1 Gbps.

Conclusion

Unlike Wi-Fi 6 consumer routers focusing on the largest reportable numbers that no one could ever achieve, UniFi series appear to design system will have a real utility. The additional price point of $200 for 2.5G-BaseT technology seems a hectic. After all, Unifi is a enterprise geared product. So it is expensive for consumer standard but still cheap for enterprise.

As a some who have just recently purchased USW-Pro-24-POE switch, I do not have intention to upgrade but if had I known this is coming for $200 more, would I have picked it? Probably yes. But when Wi-Fi 6E comes out in couple years, there will most likely be yet another speed bump, which may require 5G-BaseT technology switch. So those of us who wants to be in a cutting edge technology, it is always the associated premium price we have to pay.

In any event, the next up is ISP. The service providers will need to up their game to support over a gigabit service to more consumers.