DSL Micro Filter

Micro Filter: Use or Not?

First of all what is a Micro Filter? Basically its installed between your phone line and your DSL modem with the goal to make internet connections more stable. The typical DSL Micro Filters I know has an RJ-11 tip on one end which you plug in your telephone socket and an RJ-11 socket on the other which you will use to connect your ADSL Modem. Other variants comes as a splitter--for telephone and DSL.

DSL connections can come in two forms, Naked and Bundled. The first one (Naked) is a dedicated line for DSL connection only. Whereas Bundled connections is one line which services both voice (telephone) and data (internet). From what I have read it is advised to use Micro Filters for Bundled connections to prevent interference from either of the two frequencies (voice and data). I believe the explanation is sound, however I have no way of testing that since I only have Naked connections.

Last night I installed a Micro Filter in our office. I placed it between the telephone socket and the ADSL. Connection was okay and maintained to be stable. Well, it was already like that, so just no complain here. Until I tested it with speedtest.net. I was randomly getting the results from speedtest the whole day and to my surprise the Micro Filter instead of improving performance actually reduced my Download speed by a few Kbps. Our connection in the office is a stable 5Mbps, with the Micro Filter installed it could not really hit 5Mbps. So this evening I took out the Micro Filter and immediately did a test and right there and then speedtest registered over 5Mbps. To verify the results I conducted the test over and over again among several servers and the results were conclusive.

Again I have not tested the performance of a Micro Filter over a Bundled line, but its purpose is to protect each frequency running in the wires against radio interference. In my setup I did not need the Micro Filter since their was only one (1) radio frequency running through the wires.

The nature of the Micro Filter is not directly the cause of my setup's reduced performance. In other words filtering the connection doesn't do any damage. However as you increase the number of Hops (devices where data passes) data travel naturally increases and performance diminishes.

Note: PLDT is my ISP

WiFi All Over the House

I wanted to get my WiFi signal all over the house.

Structural challenges:

1. Two floors to cover.
2. The house is solid. Mostly concrete and hard wood.
3. Not to many options for the location of the router.

What I have to work with:

1. ZyXel Router ( P-2612HWU-F1) from PLDT (my ISP)
2. TP-Link Router (TL-WR941ND) with three (3) 5dBi antennas
3. DSL (Telephone Wire)
4. Three (3) 9dBi omni-directional antennas

TP-Link TL-WR941ND (Front)

TP-Link TL-WR941ND (Back)

The story: 

The task was to get the WiFi signal all over the house so that everybody can enjoy it--even in their rooms. I cant do so much with the ZyXel Router from PLDT. The antenna (Single 5dBi) is fixed and configuration is very limited. Although signal strength is good when in the open areas, even when at the second floor, but signal was either very poor or lost when in the rooms. Again I cant do so much with the router and wired connection of any type is not an option here.

For the problem above I thought of adding an additional router (thus TL-WR941ND). The TP-Link router would get its internet from the ZyXel which so happens to be the modem also. This connection would be wired from one of Zyxel's LAN Ports (usually color yellow) to the TP-LINK's WAN Port (usually color blue). Under default settings you should be able to get the internet from the Zyxel to the TP-Link Router as soon as you wire them together. No configuration out of the ordinary is required. But remember though for this setup TP-Link's WAN Connection Setup should be set to  Dynamic IP. This will allow the TP-Link Router to automatically get information from the other router.

To address the structural challenges I placed the TP-Link router at a very high elevation (at the center of both floors). Physically this made the router closer to each floor. I then replaced the three (3) 5dBi antennas that came with the TP-Link Router with high gain 9dBi antennas (12dBi antennas or those that come with an externally powered range booster mount would be even better). I specifically purchased this type of router because #1 the antennas are replaceable (thus I can upgrade) and #2 it has three (3) antennas and uses MIMO technology. The antennas are triangularly positioned and are tilted forward. This allowed the center of the doughnut-shaped radio signal to focus on my target "dead spots". Note that the router is placed on top of the wall on one side of the house, thus signal should be pushed forward.

At first I changed the radio frequency of both routers and distanced them to lessen interference and overlapping  (ZyXel channel 1 and TP-Link channel 4). Having other wireless devices operating close to each other in the same or close frequency would affect signal performance. But I eventually just turned off the radio of ZyXel as I didn't need any wireless connection from there.

The results:

Success! I got a stable signal in all rooms even when doors are closed. The signal strength indicator doesn't register a full signal when inside the room but its not low and the most notable part is that its stable. Ping results are also good, I got an extra hop since I have an extra router but its not a factor specially for home users.

My Actual Setup

Failed setups: (Resulted in unstable signal strength when inside the rooms) 

1. Same configuration but TP-Link router was placed at a slightly lower elevation.
2. Antennas are positioned normally (not tilted forward).

Notes:

1. Radio signals are weakened by interference (such as walls and doors).
2. The capacity of the radio signal to pass through infrastructures also depend on the materials used in your building/house/site.
3. TP-Link's firmware (TL-WR941ND) can also be upgraded to DD-WRT. But I didn't try it here. I do have a Buffalo box with DD-WRT and features are good (more benefits for advanced and IT users than home users).
4. I like Cisco (Linksys) routers but didn't use them here since antennas are built-in
5. For those with old TP-Link routers and are familiar with the old web interface, the new one is better.
6. WDS Option is available for TL-WR941ND but didn't use it here to save on the cost of a second router. I did try it (ZyXel + Tp-Link) but failed. I think it was due to some configurations in the ZyXel. Everything was good in the TP-Link box. And WDS is a whole different story.