• United States
by Steve Taylor and Joanie Wexler

Diversify, diversify, diversify!

May 20, 20032 mins

* Network-to network interfaces are still scarce, but requirements remain

As part of our five-year retrospective, today we’ll compare the newsletters we authored in early June of 1998, which discussed the need for network diversification – not only in the access link but also across core service provider networks.

On the rare occasion that a snafu causes switches within the carrier’s backbone to communicate inaccurate forwarding information to one another, the redundant paths carriers have built into their networks for diversity become useless. If yours is the type of business that can’t tolerate a single catastrophe, ever, you need to spread your traffic across multiple WAN service providers.

In today’s economy, diversification is more the rule than the exception. Businesses are worried that cash-strapped carriers might pull back on service and support or even disappear altogether. So business customers have more incentive to spread their risk around. If your network provider were to close up shop, think how long it would take to order circuits and get them provisioned if a secondary carrier weren’t already in place.

But what about getting connectivity between the diversified services? Back in 1998, we pointed out that network-to-network interface (NNI) services, which interconnect frame relay networks run by different carriers, were scarce. Unfortunately, the situation persists today in long-haul networks, both in frame relay and private IP VPN services. So how can you make sure your disparate “pockets” of users can still intercommunicate? This is where Internet-based VPN services, such as those offered by Virtela, might come in handy, since everything in the Internet can get to everything else.

Or, as we pointed out five years ago, you could still provision diverse permanent virtual circuits from a common router in your data center – one PVC connected to one carrier and another PVC connected to a second carrier.

And while we don’t formally have “NNIs” in the IP world, the interconnectivity requirements are the same. How do you make a voice-over-IP phone call from your site to someone on a different carrier’s VoIP network? For ideas on this one, please see Steve’s opinion column this week at