10 Mar 2013, 14:00

SimCity Network Traffic – World List


Like many other who have tried playing Simcity since it’s launch, I’ve had time wasted fighting with their servers trying to get online.  This motivated me to start looking at the game’s network traffic to see what I could find.

Simcity Launcher

When you initially start up the game, the launcher connects to a number of different servers; this includes the advertisement area (the newsletter in the above screenshot) and recent news.  If you click the “SELECT SERVER” button, it does a GET on this URL:

If you capture the data yourself you’ll see it actually tacks a “?###” on the URL, with ### being an 18-digit number.  This number does not seem to change between views of the server list, restarts of Simcity, or restarting Origin.  Though, launching the game on another computer behaves similarly, the number is slightly different (first 9-digits were the same). I would guess this is either a unique ID for users, or a “last changed” time, but I’m not sure yet.

World List Data

  "version": 4,
  "hosts": [
      "Desc": "Antarctica",
      "name": "0x0f3b425d",
      "url": "api.p21.simcity.com",
      "game": "api.p21.simcity.com",
      "websocket": "socket.p21.simcity.com",
      "telemetry": "http://telemetry.simcity.com",
      "news": "api.p21.simcity.com",
      "statuses": [
          "status": "available"
      "id": 999143101,
      "sort": 0

(all but 1 server has been trimmed for space reasons)

What’s listed here:

  • Name of each host.
  • 5 different servers entries per host, only 3 of them having unique DNS names.
  • A name and id that are key values for the host.
  • Status information, which is interesting on servers when they are full, as they contain both the “full” and “available” values as seen below.  It seems the client will only use the first status entry it hits.

What’s not listed here:

  • Which servers you have regions/cities on. This functionality was added with patch 1.4, but it seems it’s tracked through other means.

I’ll be writing up more on this information later, but this is a start.