Network over network

As part of the expansion of the connection between the rooms, I decided to implement new technologies that allow communication without modernizing the apartment. Searching for technologies enabling the implementation of the idea, I noticed that the most common option chosen is the wireless network, PLC and thin twisted pair (through the door). Reading various opinions about the PLC I came across many devices that did not meet my expectations. Often in the product description there was information that the maximum speed was 1300Mbps and they actually reached 150 - 200 Mbps. I postponed the topic for a while and temporarily used the bridge between MT cAP AC.

While expanding my small server environment with a 10Gbps network, I noticed that Mikrotik also produces PLC devices. Most of the products available in the company's offer provide a speed of 100Mbps plus wireless technologies and the latest PRO device that will be tested.

What is a PLC?

PLC is short for power line communication.
In non-technical language, Internet via electricity. It is a technology holding as many opponents as supporters and myself to any of them do not belong.

Device

The latest product PWR-LINE PRO, providing LAN connection through the power network, colloquially speaking Network over network. According to the specification within a top speed 600Mbps, which was not a big surprise but more of astonishment, what is the reason for such a low speed? Finding any information about this device is almost impossible, in addition to the manufacturer's website. Let me share with you my opinion about this device and verify information about its performance.

The device is in the "Data over Powerlines" category and is built on the same chipset as the competitor's TP-Link TL-PA8010P device.

The device has two sockets, the first of which connects the power cable, and the second one is for connecting a computer or device with the possibility of power through POE. I tested the POE power supply on Mikrotik CRS109-8G-1S-2HnD-IN device and it worked correctly. Between the sockets, there is a button for resetting and creating a connection between the modules. Lighted diodes inform us that the device is on (blue LED), communicates between modules (orange LED), there is an activity between computers (green LED) and active POE supply (red LED). It also has a manual switch to turn on the POE power.

We do not need anything more, the device is easy to configure. Just turn on, keep synchronization button and there is a connection between computers.

More information about the device on the manufacturer's website or online store.

Tests

Each of the tests was performed with the iperf3 program with the time set for the old apartment of 10 seconds and the new apartment of 30 seconds. I made a single connection between the computers, in most cases, it showed no diametrical difference.

The purpose of the tests was to show reliable results and to present the importance of building a power grid in various locations.
What conclusions should result from the tests performed:
- the impact of the network infrastructure on the speed,
- does the distance matter,
- whether interference devices such as a fridge, washing machine, etc. affect the transmission.

Old apartment - old network without ground

The goal is to show the operation of devices in the old power grid where it is not possible to use the 3-core cable (grounded cable) required for maximum speed.

Legend:
Strip - connection within one strip with grounding.
Room - kitchen - the same circuit with a fridge along the way - greater distance
Room - corridor - the same circuit - smaller distance

Connections under the old network are at a level adequate to the competition. Slight drops at a greater distances caused by other devices.

The network is suitable for Internet use up to 150Mbps, an additional PWR-Line with a wireless transmitter is recommended for larger connections.

New apartment - grounded network

In this scenario, I did more tests with different variants. At the beginning let's look at the chart below.

Legend:
- Room - one circuit - same room
- Corridor - one circuit - corridor on the way to fuses
- Server - separate circuit
- Living room - separate circuit
- Living room - no fridge - separate circuit - fridge off
- Living room - cheap strip - separate circuit

What was the purpose of breaking down the tests into details?

As part of a connection in one room, I wanted to check what I can get the fastest connection between computers on one circuit. I am a bit negatively surprised by the result because I expected the speed of 600Mbps and obtained 370Mbps. It's not bad but it could have been better. It is suitable for connection when we want to use a provider offering over 300 Mbps. Test made on a double socket. It is worth noting that when connecting, for example, a switch to the second socket, the speed drops to 100Mbps and is the equivalent of a connection on a cheap strip.

The test in the corridor had a symbolic purpose, it could be useful when installing an IP camera powered by POE. Transmission at an above-average level.

Server - The most important scenario, the connection from the room to the small server room came out average but better than in the old apartment. The location is in a separate circuit, has a grounding, there are no interference devices and connected to a single power outlet. The solution can be used by patient people because the speed is not suitable for communication with servers. However, the goal was simple - to make quick backups.

Living room - the largest distance between devices. The main goal is to strengthen the wireless network and provide Internet to devices such as the console and TV. In this case, the PLC was to be the main Internet provider and served as a backup link, the bridge between cAP AC works much better. Just like in the case of the Corridor, it can be used as a power supply, for communication for IP cameras or a backup connection.

In addition, I performed two tests in the living room:

Without the fridge - I checked, how the PLC works without one of the biggest enemies like a fridge. Often in various materials available on the Internet, it is said that enemies for PLCs are washing machines and refrigerators. To be honest, I haven't noticed big changes with or without the fridge turned on. Importantly, the fridge is in a separate circuit and is not connected via a strip. The fridge's greater impact on transmissions was in the old network, where the whole devices worked on one circuit.

Cheap strip - a symbolic test to check whether the use of the strip helps or harms. The connection was between rooms, where one of the devices was connected to the so-called cheap strip that has no fuse and only distributes electricity. As can be seen in the chart, it only injure and is the equivalent of a double socket connection.

The subject of the strip in the tests appeared twice, in the scenario with the Living room worsens the results but when solving P2P using the strip, it showed the maximum speed that is possible in connection with grounding (three-core wires).

For comparison, it shows a graph of connections between computers without the use of any switch devices and PLCs.

Summary

Devices worth recommending to ensure transmission and power supply of simple devices such as IP cameras or other IoTs. For less demanding people who do not want to build MESH networks, this is an ideal solution. What is worth mentioning is the increased security compared to a wireless network. As part of the PLC network, we have secure transmission, and using Mikrotik devices, we can easily further encrypt traffic using IPSEC.

The negative side of the device is that it occupies a socket. As compensation, Mikrotik provided POE power supply, which is enough for a camera, IoT, or network devices such as Switch or Access Point.

Equipment for testing has been provided by the store www.wisp.pl