HUNTSVILLE, Ala., Feb. 28, 2018 /PRNewswire/ -- Digium®, Inc., the Asterisk® Company, today announced the call for speakers is now open for AstriCon 2018, its 15th annual Asterisk user conference and expo to be held Oct. 9-11 at the Omni Orlando Resort at ChampionsGate in Orlando, Fla. Tho...