The MPLS answer

How to make the most of this robust WAN technology.

When faced with recovery after the Sept. 11 terrorist attacks, Syed Ghaus had to reroute his users to a New Jersey branch office so they could access the corporate network using dial-up connections from laptops. With a private Multi-protocol Label Switching-based network, he says, failover would have happened seamlessly.

For Ghaus, who has since joined Resun Leasing, MPLS has become a facet of business continuity. The flexible, decentralized routing structure of MPLS allows connectivity among 34 branch offices in the U.S. without requiring routing through a hub, says Ghaus, who is director of business technology at the Dulles, Va., supplier of modular buildings. Thus, MPLS eliminates the single point of failure found in traditional spoke-and-wheel networks.

This any-to-any connectivity presents a great opportunity for redundancy and seamless transition to back-up systems and applications at other locations. But as with any new technology, early adopters warn, MPLS comes with trade-offs. And without proper planning, MPLS can create more problems for business continuity than it solves.

Scott Peterson, director of network services for Accenture, points to standards as one weak point. MPLS is still new, so standards for vendor peering and multi-carrier QoS only now are making service-level agreements (SLA) achievable. So while you might have a strong MPLS network out in the WAN cloud, you could have trouble with last-mile local connections, he says.

Planning for the apps

Defining how mission-critical applications are transported over the MPLS infrastructure becomes highly important because of IP's nebulous nature, Peterson says. So you must take the time to map the IP infrastructure with performance and end-to-end management. "Then you can achieve a continuous quality of service across the infrastructure, into your data centers and remote facilities, and pass it off into the cloud" for the carrier to uphold, he says.

IT departments already should know the applications most critical to the business and how they're being used. So defining QoS should be easy. But to make your MPLS network even more fail-safe, you should take the opportunity to standardize platforms, applications and versions, suggests Jermaine Mason, IT manager at Wilson's Sporting Goods, a division of Ameri Sports in Chicago.

Then you need to select a carrier that can guarantee end-to-end service quality. The carrier also should be able to accommodate security requirements (primarily IP VPN) and support new, demanding applications (such as VoIP and videostreaming) with minimal latency, early adopters say.

Large carriers offer two ways to allocate bandwidth - static and dynamic. MCI, for example, offers committed access rate for static bandwidth allocation and supports differentiated services for dynamically allocating bandwidth to applications that otherwise would be affected by link failures or congestion. Some carriers offer the ability to directly run over the Internet using a VPN, which most companies chose for better privacy and reliability.

But not every carrier supports dynamic bandwidth allocation, so getting exactly what you need from your MPLS network might require writing your own tools, early adopters say.

Champps Entertainment, for example, uses an MPLS VPN from Netifice Communications to create any-to-any tunneling between 51 restaurants and the Littleton, Colo., headquarters. "When moving to the MPLS VPN, we . . . wrote a homegrown application to crank up and down the amount of bandwidth to make room for videoconferencing when needed," says Steve Johnson, IT director for Champps.

Managing MPLS

Another gotcha with MPLS can be management complexity, as those same routing redundancies that make MPLS so  hardy also make it more difficult to manage. With MPLS, you need a way to monitor your network to check on bandwidth allocations and hold service providers accountable to SLAs.

"We're trying to run transport at 300 milliseconds or better from global offices to our centralized data centers," says Peterson, who uses an integrated, multi-vendor suite to manage and monitor Accenture's MPLS infrastructure. "We want our network to be a business enabler, not the other way around."

Most businesses manage to their edge routers and then hand off management to the carrier, although carriers such as MCI will manage all the way through to the data center if clients are willing to pay for the service and are willing to give up control. "I wanted a hybrid relationship with my carrier, so I manage my part of it, and MCI clearly knows what it's responsible for," Ghaus says. "This reduces finger-pointing by a great deal."

Finally, to prevent outages during the transition to MPLS, Johnson recommends running the MPLS network in parallel with your current network for a few months to be sure everything's going smoothly before completing the transition.

"You need to understand you can mess up your installation if you don't introduce quality of service on your network before you move to MPLS," Ghaus says. "Know your network. Know your business. And know the applications. Then take all this information and overlay it on top of your MPLS."

Copyright © 2005 IDG Communications, Inc.

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