Nortel has been manufacturing phones for business users since the 1980s beginning with the Meridian series phones.
A list of past and current products:
Nortel no longer makes the above listed business phones and are now made by Aastra Technologies Limited of Concord, Ontario since 2001.
Due to Proprietary Digital Signalling VoIP ATA cant be use for VoIP Enable this Phone, Portico TVA allows these phones to seamlessly integrate with softswitches .[1]