Digital extensionthe nec xn talk system telephone is a digital telephone designed to work on the nec xn120 telephone system it needs to be connected to a digital extension on the nec system as it can not function on a standard analogue telephone socket another model available in the xn range is the xn vision which has similar features to the xn talk except it features a visual display as well22 programmable buttonsthe nec xn talk has a number of fixed buttons as standard and also 22 buttons t