Even a $10M upgrade won't fix congested Internet exchange points

What does $10 million get you? Maybe only a Band-Aid if you're operating some of the busiest Internet exchange points in the world.

That is what WorldCom, Inc. is spending to fix MAE-East and MAE-West, its two metropolitan area exchange (MAE) points that are buckling under the demand of Internet service providers. But according to most industry observers, WorldCom's two-year $10 million antidote will not be the cure.

The dramatic growth of the Internet increasingly translates into intense packet loss, frequent switch rebooting and overall network congestion at the more than one dozen MAEs and network access points in operation. And that means headaches for businesses that depend on the 'Net.

Dwight Gibbs, chief technical fool for Web-based financial advisory firm Motley Fool, knows this firsthand. His users accuse him of poor quality of service when Web pages are slow to appear. He then shows them trace routes he has done to track where slowdowns occur and points to congestion at the MAEs, he said.

WorldCom and the ISPs have identified the problems as head-of-line blocking, which causes pipes into the exchange point to jam up, resulting in packets being dropped, and congestion. Dropped packets mean ISPs have to dedicate more resources to retransmitting, which, in turn, wastes bandwidth. Nowhere is the dramatic growth of the Internet felt more strongly than at WorldCom's MAE-East, in Vienna, Va.; the busiest MAE.

Packet loss at MAE-East has recently approached 40%. As a result ISPs that link to the MAE to exchange traffic with other ISPs are screaming for upgrades. WorldCom, which got the job of fixing the MAEs when it bought original architect MFS Communications Co., Inc., has answered the call with more Digital Equipment Corp. FDDI GIGAswitches, but most observers believe FDDI's days are numbered.

Past and present

Less than four years ago, MAE-East had a single GIGAswitch. Today, it has seven - three of them deployed this year as the first part of the MAEs' overhaul.

To put further packet loss at bay, MAE technicians recently revamped the MAE-East architecture. What was simply a ring of GIGAswitches strung together has been rearchitected to a mesh formation with one switch at the core.

"We've also dispersed high-load customers to reduce the stress on a single switch," said Larry Walberg, director of global network operations at WorldCom.

Despite these fixes, WorldCom believes MAE-East still will reach full capacity by January, said Dan Lasater, vice president of broadband applications at WorldCom. But if even one exchange point is going to reach full capacity in a handful of months, why invest millions in FDDI?

This question has many scratching their heads.

There are really only three technology choices for MAE and NAP operators today -- ATM, Gigabit Ethernet and IP over Synchronous Optical Network (SONET), said Tim Weingarten, research associate at BancAmerica Robertson Stephens, a San Francisco-based consulting firm.

These technologies support wire-speed switching, unlike FDDI, he said. When the MAEs and NAPs were first constructed, FDDI was a good, solid choice, Weingarten said. But not today. FDDI can only switch at 100M bit/sec. If you are connecting to a MAE with an OC-3 or OC-12 connection, you will not get 155M bit/sec or 622M bit/sec respectively, he said.

Although the second installment of the $10 million will fund research to determine which of these technologies is viable, principal MAE architect Steve Feldman said WorldCom is not ready to commit to a single architecture but is considering all the options.

ISPs that are dependent on the MAEs are not happy with WorldCom's choices thus far. "There has to be more thought put into the scaling of the interconnects," said Rodney Joffe, chief technical officer for Phoenix-based ISP Genuity, Inc.

Joffe contends that WorldCom is already too late to solve the problem. "They should already be up and running with a test bed."

"The MAEs suck," said Motley Fool's Gibbs. He has been dealing with the MAE problems for many months now and is excited when UUNET Technologies, Inc., his ISP, enters into private peering with his customers' ISPs.

In fact, private peering is quite popular among the top-tier ISPs. Private peering arrangements are typically two dedicated T-3 connections between two ISPs. Each ISP takes responsibility for one of the T-3 lines. Here, ISPs can exchange traffic without going through any of the public exchange points.

However, all maintain public peering connections to MAEs and NAPs around the country.