TP-Link TL-PA551KIT AV550+ Gigabit Powerline Kit With AC Passthrough Review

by - 9 years ago



In the grand scheme of networking vendors, TP-Link is not going to be the first brand amongst the big players that one would normally think of, but this is not to say that they are a small company. For a number of years, the Shenzhen based company has been making networking products ranging from un-managed switches, through to routers, wireless adaptors enterprise level managed switching gear. With the recent introduction of powerline technology, its only to be expected that powerline adaptors are going to be a part of their growing catalogue of products.

The 500Mbps kit that I’m going to take a look at today is not the first powerline kit to come out of the TP-Link production line, with a 200Mbps kit already available, but this kit sees faster speeds with a [up to] 500Mbps link speed and Gigabit Ethernet on each plug. Another feature that the TL-PA551 offers up is AC pass through which as simple as it sounds, allows the plug to still be used whilst the powerline does its work.

For those of you out there that follow my reviews, I hope you recall the time when I was very hesitant about powerline technology but with this view very much reversed, it seems I’ve grown a soft spot for it, as it can easily link different areas of a house together with ease and with no fuss – with some kits on offer that eliminate WiFi black spots or remove the need for wireless extenders altogether. This kit though with its AC pass through and Gigabit Ethernet ports is already looking to me to be a great option as it has the prospect to give a more than adequate throughput speed whilst still allowing the plug to be used for another electrical device.

TP-Link off this particular model in two SKUs, the first is a single plug which can extend an existing TP-Link powerline set-up even with 200Mbps models as they are full backwards compatible. The second variation and the one I have here to look at is a starter kit with two plugs and two cables. Also included is a set-up CD with the Powerline Utility, a user manual and a leaflet for some of TP-Link’s other products.


A Closer Look

Looking at the plugs, the first thing that is apparent is their rather bulky size, however this is down to the AC pas through feature which allows the plug effectively to still be used for other electrical items, whilst this sits in the middle giving network connectivity at the same time.

Lower down on the front are three LEDs indicating power, LAN activity and power line status / strength. When the Ethernet connection is disconnected (when a device is turned off for example) the plugs go into a idle state and this is indicated by a slow pulsing power LED.

On the lower edge of each plug is a Gigabit Ethernet port and to the side a pair button to establish the connection in a powerline setup. Whilst the plug offer up a Gigabit connection, the link speed between the plugs is [up to] 500Mbps and it should be noted that the speed experienced may be lower depending on the location of use as we will see later on.


Test Method & Utility

Test system:

  • Asus Maximus V Formula
  • Intel Core i7 3770k
  • Corsair Vengeance 1866MHz 16GB
  • XFX Radeon HD 7970
  • Corsair H100i
  • Corsair HX1050W
  • Kingston HyperX 240GB SSD
  • Asus V247
  • Dell XPS 15 Laptop
  • TP-Link TL-PA551KIT Powerline Kit

We would like to thank AOC, Corsair, Kingston and Lian Li for supplying us with our test system components. Many different software applications are also used to gain the broadest spectrum of results, which allows for the fairest testing possible.

Software used:

  • LAN Speed Test


When it comes to testing a powerline setup, there are many different factors that have to be taken in to account with regards to how the system performs at different distances. Naturally the biggest player in this is going to be the wiring system in the environment where the plugs are going to be used. Older electrical systems typically should expect to have a slightly lower performance level to newer installations and then there is also the distance between the plugs – you have to remember as well that this may not be as direct as you may think as most household systems run on a ring and if you’re going between floors then this also means the signal is likely to pass through the main fuse board at some stage.

To test the plugs, I set them up in three locations, the first (as seen below) is with them right beside each other. No of course this is not going to be a real world situation, but what it does give is the best case scenario for them to perform at their best. After this we will put them at a medium range (in this case on the next floor down in our small office) and test the speed. After that the third distance is down yet another floor at the farthest point to the other plug as I can place it.

These three distances and the resulting speeds should give us a good idea as to how the plugs can perform.

LAN Speed Test a a simple free to use application that creates a file of any given size and pushes it across a network to a given destination folder, measuring the maximum speed of throughput during the file transfer. To get a better and more accurate throughput speed, we set the file size to 1GB. To add a variation to the data set, we tested the adaptors at a varying range of distances by plugging in one plug next to our switch and then the other to start right next to it. We will then move the other plug furthest point we can (roughly speaking) and then half way between to see how distance affects throughput.

In a co-located position, the TP-Link Powerline adaptors show that they have strong potential to give good speeds when the conditions are perfect. We do find however that with this kit, that as the distance increases, the speed does take a notable fall, dropping to just under 60MB/s during the long-range test.


Final Thoughts

Since powerline kits have been about, avid readers will know that I have grown upon the technology and now use it myself as a means of extending my network to a far point with ease. There has been one slight downside though that I have seen with many of these kits and this simply comes down to the Ethernet ports that have been installed into the plugs versus the speed that the powerline link runs at. When you think about it, it does make one wonder what the point is in having a 200Mbps or even a 500Mbps link speed between the plugs when the connected devices can only run at 10/100 Ethernet speeds, after all the network will only be as fast as the slowest link component.

This imbalance between the Ethernet and link speed is where the TL-PA551 comes into an immediate advantage. The inclusion of a Gigabit Ethernet port on each PA551 plug allows each connected device to take the full advantage of the 500Mbps link speed that runs through the power system of the house. I’m not going to write off the fact the having a higher link speed is pointless however. It all comes down to the way the plugs are used; if a single pair of plugs are being used, in the same way that I test them, then there is going to be an advantage to having a faster Ethernet speed over link speed, allowing the user to make the most of what’s available. On the flip side however for situations where there is multiple plugs connected into a powerline group, then the faster link speed will allow for more fluid backbone connections.

The PA551 in a co-located set-up, as mentioned on the previous page, gives a good level of performance and whilst there is a notable drop in performance in our testing when the distance is greatly increased, I will have to point out that this is not necessarily going to be the case for all installations as the quality of wiring and distance of the cable runs in walls does vary greatly, thus being the major factor with the quality of connection and speed. Over the PA511, the PA551 does also offer an AC pass through, which is a feature that many will overlook. Being able to plug another electrical device into the powerline adaptor is an easy way to save on buying extension leads and multi-sockets to give extra power behind a TV or computer for example, just for the sake of giving that location LAN connectivity as well.

Overall I’m impressed with the PA-551 powerline adaptor and to add to the features available, this kit is fully backwards compatible with the other powerline products that TP-Link feature in their line-up. The AC pass through is not a first in this product class so I can give the kit our Innovation award, but when we look at the price point of a shade under £80 (~€93 EUR / $124 USD) they’re a damn good bargain, working out at half that price each in this instance – that’s surely worth our band for buck award.


  • Gigabit Ethernet ports
  • High speed 500Mbps link speed
  • High affordability
  • AC pass through
  • Simple to use


  • Bulky design
  • Possibility of notable drop in performance due to older electrical wiring

eTeknix says: “Powerline technology is getting stronger and stronger and consequently the speeds that we are no seeing possible is becoming ever more close to a pure Ethernet network – the PA551KIT is a great example of this and the AC pass through feature on top of this gives this kit a huge list of selling buzz words. Certainly one of the top kits that I’ve seen so far.”

TP-Link TL-PA551KIT AV550+ Gigabit Powerline Kit With AC Passthrough


Article Index

  1. Introduction
  2. A Closer Look
  3. Test Method and Utility
  4. Performance
  5. Final Thoughts
  6. View All

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