How North and South Korea talk to each other

This office was designed to foster ties between the two Koreas … until the North blew it up.

South Korea’s president is imploring dialogue.

But what does "dialogue" look like between two states technically still at war?

Well, communication tends to revolve around ‘hotlines’.

Numerous ministries and offices run different lines -- 49 in all.

They are used for everything from arranging talks, to coordinating sea and air traffic.

In terms of physical equipment, photos by the South’s military show drab desktop phones -- labelled “two-sided inter-Korean hotline”.

The South's Unification Ministry handles civilian inter-Korean affairs.

Its system features two color-coded handsets.

A red phone is for incoming calls from the North, green is to make outgoing calls.

No other numbers can be called, and fax machines are used to send documents.

So -- how often are these hotlines used?

The North tends to abandon the hotlines when relations sour -- despite the South keeping up appearances.

Officials still typically try to call every day at the same time, even if there is no answer.

Lines were last restored in 2018, after being cut two years earlier.

A direct connection was set up for the first time between the offices of the two leaders, but it has reportedly never been used.