The $2.4 billion "is an important number to understand," said Joel Hackney, president of 's enterprise solutions unit. "That money allows us to deliver products we have committed to customers and [continue] product support."

Hackney said that as soon as the bankruptcy filings were announced, he called the CIOs at Nortel's five largest customers to explain the move. "They're savvy, and they get it," he said.

IT managers who might consider switching to rival vendors should look at why they chose Nortel in the first place, Hackney added. "I'm absolutely convinced that our value proposition only gets stronger with the financial protections," he said.

Nortel has debts of about $4 billion and was due to make a $107 million bond payment last week. said in a statement that the bankruptcy filings would enable the company to restructure and narrow its focus.

The International Nortel Networks Users Association, a Chicago-based group with about 4,000 members, issued a statement saying that the filings will give the vendor "an opportunity to truly focus on strengthening" its financial position.