Why is my WiFi so slow and unreliable?
90% of problems tenants have with slow Internet are due to issues with their WiFi (the connection between the device and their router, not the internet connection), which in turn are nearly always issues fundamentally due to the fact that the WiFi signals travels through a shared medium - air. You can imagine that in such densely populated apartment buildings there is an abundance of WiFi networks all talking over one another.
Tuning WiFi is complex, but an educated guess is that:
- You experience "co-channel interference", meaning other WiFi routers/APs1 - are "talking over" your router & device. Potential fix: Pick a different (and perhaps more narrow) channel on your WiFi router/AP. The 5Ghz band is also generally less congested and will provide more consistent speeds, especially in small apartments.
- Your router is old and uses a spectrally inefficient communication mode. Today, WiFi 6 (also known as 802.11ax) offers the best chance of working WiFi due to its OFDMA (Orthogonal Frequency Division Multiple-Access) feature. Basically, the newer the WiFi standard the more bits per airtime-frequency unit can fit, giving more room for more information in the air. OFDMA allows the interaction between WiFi router/AP and client to reserve mere fractions of the airtime, sufficient to send tiny but frequent amounts of data, which is very common.
- Your neighbours' routers are configured to transmit with too much power. Unfortunately, there is not very much we can do to fix this other than supplying information, or providing the WiFi routers/access points in each apartment (something we do in newly built apartments like Emilsbro) and manage them centrally to make sure they don't interfere with eachother. The reason this help is because it adresses all solutions below:
How do i fix this?
- Make sure your Wifi Router or AP is of an up-to-date standard, such as WiFi 6 (802.11ax) or newer. If it isn't, it could be worth considering purchasing one that is.
- Reduce co-channel interference by selecting a radio channel different from your neighbours. Note that depending on the channel width a lot of channels overlap.
- Ask your neighbours to reduce the transmission power of their router (and do the same for your own) in order for the WiFi to not leak too far outside the apartment.
: Can be other radio transmitters too, both 2.4 GHz and 5 GHz are unlicensed spectra. We have seen wireless TV extenders, etc, cause interference.
Why don't I get the 1000/1000 Mbps you promise?
The reason is either due to a limitation of your router or the method in which you are testing the connection speed. For speed testing ideally you should connect a network cable from your computer directly into the apartment’s network port (bypassing the router). Second best is to connect it to one of your routers LAN ports.
The 1000/1000 Mbps relates to the Ethernet link bandwidth between the network switch connected to the other side of your apartment’s network port, and your device. It is not very meaningful to try to measure the speed of the Ethernet port using WiFi (see the slow WiFi question for more details.)
- Often when tenants contact us about only getting for example 90-95 Mbps, even when using a network cable to perform the test, it is commonly because the tenant's router claims a higher speed (for example 1300 Mbps), while it actually only has a 100 Mbps WAN (upstream/Internet) port. The 1300 Mbps here is unfortunately "sales math", referring to the sum of the maximum WiFi bandwidth potentially possible for the device to communicate with - but only to/from clients connected directly to it. If your router only has a 100Mbps WAN port, then you will have to buy a new router with 1000Mbps WAN capabilities, commonly known as gigabit routers, to reach speeds over 100Mbps.
- Other times, tenants can measure perhaps 300-500 Mbps using a network cable, and it turns out that is actually the maximum performance the router is capable of delivering. There have been rare cases where activating a performance/turbo feature in the router has improved this. The speed is also dependent on the client that you're testing on, so make sure to close background programs and use an incognito window in your browser to ensure that extensions aren’t slowing down the client.
- Because of the 1000 / 1000 Mbps definition applying to the Ethernet layer (Layer 2) in the network stack - maximum available bandwidth for eg. TCP payload is around 950 Mbps, due to the overhead of the protocol. A test performance above 850 Mbps is very good. Sometimes test servers or the path between the test servers and CSBNET can be congested, which reduces the speed. Also, the network distance (round trip time) between your computer and the test server can impact the measured performance due to the way congestion control algorithms work. We have a on-net iPerf3 server available for testing at iperf.csbnet.se with standard ports. This server is currently connected using only 1000/1000 Mbps itself, so congestion is possible. Wait a bit and test again if the results are bad.
How do I activate Internet in my apartment?
Connect a router to your broadband network outlet port.
All apartments at Chalmers Studentbostäder have 1 (in some cases more than 1) broadband network outlets. In all locations (except Kapellgången, Landala), these provide a 1000/1000 Mbps Internet connection through Chalmers Studentbostäder's own network, CSBNET.
In some locations (Gibraltargatan 78) there is a pair of network outlets in your closet/storage room, while in others (Dr Forselius Backe, Gibraltargatan 84-92 (newly built top floors), Gibraltarkroken 4, Gibraltarvallen 2), there is a so-called 'media cabinet' (typically situated near the fuses):
This is where the incoming network cable from our switch room arrives in your apartment, and the other network outlets in your apartment are connected to.
- Option 1: You place a router in the cabinet / storage room, connect the port named WAN/Internet to the incoming network port. You then connect the LAN ports of the router to the remaining, apartment-internal, network outlets. This way you can connect devices using a network cable for better performance in your apartment. If you need multiple cables connected near your desk or similar, you can place a small network switch there.
- Option 2: You connect a short network cable directly from the incoming network port to the apartment-internal network port of your choice, and you connect your router at the other end of that outlet.
You can find a document with images explaing Option 2 here in swedish and english.
What can I do to have a good Internet connection?
The following general advice, if followed properly, will avoid many common issues with your Internet connection in your apartment!
- Connect a router (not an Access Point) with the WAN/Internet port to the broadband outlet. (For advanced user: Make sure NAT is enabled in the router to make sure your devices receive private addresses.)
- Connect your devices which have network ports using a cable, for better performance and reliability.
- Make sure the router has Gigabit ethernet (1000 Mbps) capacity on the network ports. An example of such devices is given here: prisjakt.nu (sorted by popularity, not by price)
- Make sure the router supports 5 GHz WiFi channels and use one of these rather than the 2.4 GHz WiFi channels, as the 5GHz radio spectrum is faster and usually less prone to interference. Check your router's documentation or search for how to do it online.
I'm experiencing a slow Internet connection and I have a router connected to the broadband outlet
Each apartment's broadband outlet is connected to a 10/100/1000 Mbps capable network switch port. If you experience slow speed with your router, there are a couple of things to check in order to determine where the bottleneck is.
- It is useful to measure performance using an appropriate tool. A simple test tool to use is to open https://bredbandskollen.se in your browser and then run the test ~3 times.
- It must also be stated that Chalmers Studentbostäder (through BrainMill AB) does not guarantee any specific performance at all when using WiFi, due to:
- the physical reality of the air medium being very suspectible for interruptions and disturbances,
- the fact that a very wide variety of routers are used.
- the air medium being a shared medium between you and all your neighbors within range using the same WiFi channel.
We do however want to help you achieve an overall good working Internet connection at home.
If you do not have any device with a network cable port, you can borrow a USB-A/USB-C Ethernet adapter for troubleshooting purposes from Chalmers Studentbostäder customer service. This is agreed with us during the handling of the support case.
- If you are using WiFi, connect a device using a network cable directly to the router and then run a speed measurement.
- Connect a device using a network cable directly to the broadband outlet in the wall, replacing the router for the duration of the test, in case you have one, and then run a speed measurement.
Depending on outcome of the two previous tests, you should be able to conclude if the bottleneck is the WiFi, the router, or if you genuinely get low performance from the broadband outlet in the wall.
Next steps include:
- Check your router model: Surprisingly many have routers that only manage up to 100 Mbps speed, not the full 1000 Mbps the network supports.
- Upgrade firmware on your router. See your routers documentation for how to do it (search it online).
- Reset your router to its default factory settings (see documentation or search online for how to do it).
- Make sure you use 5 GHz channels for WiFi, if you can.
I experience issues reaching a certain service on the Internet:
The internet works so well these days it is easy to forget it is not absolutely perfect. Some times services goes down, and it has nothing to do with Chalmers Studentbostäder's network. When this happens, there are several ways and steps available to figure out how big of an error there is.
For the below cases, we advice you to follow the general fault isolation routine as follows:
If you are using WiFi, connect a device using a network cable directly to the router. Test functionality by browsing somewhere. Report what https://ip.csbnet.se tells you.
Connect a device using a network cable directly to the broadband outlet in the wall, replacing the router for the duration of the test, in case you have one, and then test functionality by browsing somewhere. Report what https://ip.csbnet.se tells you.
Depending on outcome of the two previous tests, you should be able to conclude if the fault relates to the WiFi, the router, or if your issue is isolated to the broadband outlet itself.
My outlet appears physically damaged
Create a fault report on CSB's website