External Connection Terminal

An External Connection Terminal (外部接続ターミナル) is a terminal which allows connection to the internet outside of Academy City.

Principles
Academy City runs on its own network and is detached from the normal internet that the rest of the world uses. The external lines that connect to the outside internet all have to pass through an External Connection Terminal to make contact. There are four terminals found in the north ( District 3), south ( District 2), east ( District 12), and west ( District 13) of Academy City. In an emergency they can all be cut off to completely separate Academy City from the outside internet.

Battle Royale Arc
BLOCK begins their move on October 9, hacking the Virus Isolation Center and the External Connection Terminals and spread the viruses through them and at the same time hack Hikoboshi II's satellite control center as so they can use the satellite. This simultaneous attacks would then confuse Academy City's network countermeasures team and split the forces that would be sent out to deal with it. BLOCK's main goal with the hacking however was to take down the surveillance system that Hikoboshi II satellite had and deliberately spread false information of using it's large caliber ground-attack laser to attack District 13.

was contacted about a cracking attempt being carried out against the Center. Due to an attempted assassination of Oyafune Monaka by SCHOOL earlier in the day, it was assumed they were behind it. Knowing the damage an Academy City virus would wreak when it is leaked the External Connection Terminals begin shutting down in order to prevent their spread. All of the terminals other the one in District 13 have been cut-off as a result of BLOCK's attack, forcing  to go the district to stop it themselves. While doing so, they later receive a report of the satellite control center for Hikoboshi II, forcing to split up responsibilities. Accelerator goes to District 23 to destroy the antenna that is for the satellite, while Tsuchimikado Motoharu and Musujime Awaki continue towards  District 13. Both later succeed in their actions, with Accelerator inadvertently fulfilling BLOCK's desires. Meanwhile, Motoharu and Awaki just decided to blow up the center of the facility, ending the danger of the viruses from the Center from spreading.