Nortel is in the news as it weighs bankruptcy. Rich Tehrani has an historic view of Nortel here, as he makes an excellent point:

Sadly, we are learning now (as we do in every downturn) that branding, marketing and "perception augmentation" is something that needs to be done constantly. In good times and especially in bad.

Nortel is experiencing what the VoIP hardware market is feeling: not enough money for everyone to live off. If Cisco is reaping the most benefits, the rest of the hardware companies have to learn to live with a diet of scraps as consolidation and trimmed CAPEX hits the industry.  How many Class 5 or Session Border Controllers do you need before you have maxed out?

Nortel suffers from what many companies do: You cannot be everything to everyone.  You need an Identity that Differentiates you from the pack.