Thursday, 27 December 2018

The Stockholm Metro: A Guide/Review

Hello, all readers. This is my first post on my new blog. I will be posting here write-ups of my travels, reviews of transportation systems, and also some tech related stuff. I am writing this on board a ferry coming back from my visit to Stockholm, and this post will be a guide and review of the public metro system in Stockholm.


Construction of a section of the metro just north of T-centralen in 1957
The first line of the Stockholm Metro opened in 1950. Prior to that, several tram lines were built to metro standards, to later form part of the metro system - these were called "pre-metro." By 1957, the former short sections of metro lines were connected at T-Central station, forming the Green Line. Later, the Red Line was opened in 1964, running from T-Central to Fruängen and Örsberg, and was extended to Mörby Centrum in 1978. By that time, the Blue Line had been running for 3 years, with 2 lines heading northwest of the city centre. The newest station, Skarpnäck, was opened in 1994, and is the 100th station on the network.

The Network

The Stockholm Metro consists of 3 colour-coded routes - the former Green, Red, and Blue Lines. These are sometimes referred to as Subway Systems 1, 2 and 3 respectively. Routes are served by trains on different services, each with their own number. These run along the same route for the most part, but have different termini.
The Stockholm Metro network diagram. Source: MTR
There are a total of 7 different services.
  • 10  Kungsträdgården – Hjulsta
  • 11  Kungsträdgården – Akalla
  • 13 Norsborg - Ropsten
  • 14 Fruängen - Mörby centrum
  • 17 Åkeshov – Skarpnäck
  • 18 Alvik - Farsta strand
  • 19 Hässelby strand - Hagsätra
The Red and Green routes share tracks between T-Centralen and Slussen, and cross-platform interchanges are available. In addition to T-Central, there is only 1 other interchange station between routes on the network: Fridhemsplan.


The Stockholm Metro forms part of SL's urban transit network within Stockholm, and accepts SL Access smart cards for ticketing. These cost 20 SEK, and are available from metro stations and Pressbyrån kiosks. These can be topped up with credit for single journeys, or time limited travelcards (e.g 24 hours, 72 hours, etc) for unlimited rides within a set time. There are discounts available for young people (under 20 years old), seniors and students in Sweden. A 24 hour travelcard for adults costs 125 SEK, 72 hours is 250 SEK, and 7 days is 325 SEK. For people entitled to discounts, they cost 85, 165 and 220 SEK respectively.

For visitors who only make 1-2 journeys, paper tickets are still available from ticket machines and from the SL mobile app. A single ride ticket for adults costs 44 SEK, 30 for people entitled to discounts.

Technical Details

The 3 systems of the Stockholm Metro operate on different signalling systems as well. On the Red and Blue lines (Systems 2 and 3) the old system is in use, manufactured by Union Switch & Signal, and on System 1 a newer system enabling Automatic Train Operation (ATO) made by Siemens. All systems use a 3rd rail power supply, with a nominal voltage of 650V on Systems 1 and 2, and 750V on System 3.

There are 4 models of rolling stock in operation: the modern C20 trains, and the older Cx trains: C6, C14 and C15. C6 trains run on System 2, C14 and C15 run on System 3. C20 trains make up the majority of the fleet, and run on all lines. System 1 is the sole domain of the C20, due to the new signalling system. C6 units were built in 1970-1974, while the C14 and C15 were built from 1985-1989, both by ASEA. The C20 trains were built by Bombardier in Kalmar Verkstadt from 1997 to 2004. 

C6 train 2664 at T-Central, running on service 14

C20 train. Source: Jognes, Wikimedia Commons

My impression

The metro in Stockholm was the first metro I ever took, and it is very well operated. The stations are clean, accessible, and the signage is clear - even for someone who speaks no Swedish. The C20 trains are modern, clean and comfortable, however drivers tend to handle the train a bit aggressively outside the Green Line, so make sure to hold the handrail when standing. The fares are reasonable, considering the purchasing power of the SEK. The Stockholm Metro is a good way to get around the city - for both locals and visitors.

Wednesday, 19 December 2018

Telia (formerly Elion) TV on a 3rd party router: Part 1

The largest internet service provider in Estonia is Telia Eesti, formerly operating as Elion. Along with broadband internet, they provide a TV service, using IPTV technology. Since this is a rather new technology, it has yet to be standardised, and every ISP operates it with their own parameters. As a result of that, customers are often required to use a router provided by the ISP, in this case Telia, to gain access to IPTV services, since they are distributed via the same broadband connection. However, with a bit of work, one can use IPTV with a router obtained through another party on Telia.

A bit of background

IPTV, or Internet Protocol television, is a term describing the delivery of television content via the Internet Protocol. This is different from internet television, which is the delivery of content over the Internet. Even Telia offers such a service - minuTV. IPTV differs from that since it is only distributed over a restricted network (Telia's IPTV network), and requires a special device to view (a set-top box from Telia, such as an Arris VIP5305.) Telia's closed IPTV network is accessible to everyone who has this service activated under VLAN ID 4. The Inteno DG200A, DG301 and DG400P routers offered by Telia are pre-configured to connect to that VLAN, and the STBs on the local home network get their content by proxy from the router.

Live TV channels are distributed as multicast groups, each with their own IP address, such as To join one of these groups, an STB sends a request via the IGMP (Internet Group Management Protocol) to the entire network. The router receives the response, and forwards the request to the IPTV network, where the channel becomes available to the router. A live video stream will then be continuously sent to the whole local network, and it's up to switches on the network to filter out the stream (IGMP snooping). Telia's routers do this automatically, but if the STB is behind another switch, it might not do that. The stream will get to the STB, which will decrypt, decode the stream and play it on a connected screen. Recorded programmes, rental movies, and other non-live content is available by a standard video stream from the IPTV network. For this, the STB simply requests content directly from the server, and the router is set up to forward that request to the IPTV network, rather than the Internet.


To use Telia TV with a 3rd party one router, one must first have the Telia TV service activated on their home broadband connection. This is tutorial only applicable to DSL or Fibre connections, it is not required nor possible on F4G. One must also have a 3rd party router, however special requirements need to be considered when buying one. It must support custom firmware, or be configurable to connect to VLAN 4 on the WAN side, in addition to the untagged internet VLAN. I personally used OpenWRT, however people have had success with earlier versions of DD-WRT as well. Information on hardware compatibility and flashing instructions can be found on their respective websites.

Sandy Bridge, nor the author of this blog is not responsible for any damages caused by modifying critical system components of any router, gateway, CPE, or any other piece of network equipment. Flash firmware at your own risk!

This is the end of part one. Part two will be on 2 ways to set up IPTV, with detailed instructions for both, on OpenWRT.