From: http://www.civilwarsignals.org/1st/epalexander/epalexander.html Known to his friends as "Porter" he had a wonderful childhood at Fairfield, knowing many of his father's plantation slaves, calling them by name and eating and playing with their children
He had a different nickname, though. From the same source: As the two armies were positioning themselves, Porter earned the nickname "the cuss with the spy glass" from the Federal troops, because he was shelling Federal sharpshooters with one of Capt. Moody's 24 pdr. howitzers, his favorite type gun.
But as you asked how he wanted to be called by his friends, my answer is: Porter