I've just seen a post regarding the gunfire falling silent at 11am at the end of the war and another thing saying when the agreement was signed at 5am that day 11,000 people died leading up to 11am

Who got together to say ok, ok let's stop this at um, 11am

How did they communicate this out to the battlefield, obviously technology wasn't as good as it is now

At 11am did the people just stop shooting, get out of the trenches and walk off? How did it end?