[qi:gigaom_icon_voip] The piece-by-piece sale of fallen Canadian giant Nortel (s nt) continues. Avaya, an enterprise telephony company that was carved out of telephony’s fallen star, Lucent Technologies (s lu), has bought Nortel’s PBX business for $900 million in cash, the two companies announced today. Initially Avaya had bid $475 million for the business, but raised its offer. Avaya is going to spend another $15 million for an employee retention program. Verizon (s vz) recently filed a motion to block this deal on the grounds that it doesn’t take into account the current installed base of Nortel equipment. What do you think? Did Avaya get a good deal or did they overpay for a legacy business that is slowly shrinking and losing ground to Cisco (s csco) and upstarts who are offering open-source PBX options?