Leitner Corded Compat Settings. Leitner headset + an Easy Connect cord would only have compatibility switches in the headset part Leitner headset with a Leitner Avaya cord or a USB cord you will have TWO compatibility switches (headset & qd cord) Common known compats ( If these compats do not work, encourage a quick experiment until you find the right ones) Computer: 2 & 3 (Older QD cord also had their own set of compat switches [which should also be set at 2 & 3], but the newer ones DO NOT) Aastra: 2 & 3 Alcatel: 2 & 3 Avaya: Headset - Unknown, QD Cord - 6 or 7 Cisco: 2 & 4 or 1 & 4 Cortelco: 2 & 4 Mitel: 1 & 3 or 2 & 3 NEC: 2 & 3 Nortel: 2 & 3 Panasonic: 2 & 3 or 2 & 4 Polycom: 2 & 3 or 2 & 4 Shoretel: 2 & 3 Yealink: 1 & 4 or 2 & 4 Zultys: 2 & 3 Grandstream: 2 & 4 All cordless phones: 2 & 3