Let IP VPNs roll: WorldCom's MPLS-based VPN is a single solution for investment banker Putnam Lovell - Technologies Work

Putnam Lovell not only saw the quality of its video traffic improve after it began using WorldCom's Private IP service a year ago, but as an investment banker particularly appreciates the cost savings from the new service. According to Rodric O'Connor, Putnam Lovell's CTO, the company has reduced its telecom costs by about 20 percent because it also uses the service for its data and voice traffic. Moreover, Putnam Lovell is getting more bandwidth for less; whereas previously it had 1 Mbps of capacity for data traffic between its San Francisco and New York offices, it now has a 3-Mbps pipe for its data, voice and video needs. The company estimates that on average this yields about twice as much bandwidth for data whenever there's no video traffic.

Janel Crabtree, WorldGom's director of global VPN services, says WorldCom has seen a "lot of success" with the service which it launched early last year. It is also WorldCom's only network-based VPN offering; WorldCom's other VPN service, IPSec, which WorldCom has been offering for the past three years, is only offered as a CPE-based service. Although initially Private IP used the ToS (Type of Service) method to prioritize traffic, it has recently upgraded its network to use the more complex DiffServ mechanism for giving one type of traffic precedence over other types. With DiffServ, Private IP offers customers four service classes-expedited forwarding for real-time traffic, two classes of assured forwarding for mission-critical traffic, and best effort-instead of the three that were previously offered with ToS.

Private IP also uses what WorldCom officials call a CAR (committed access rate), which guarantees bandwidth to the Private IP network, somewhat analogously to the CIR (committed information rate) used in frame relay networks. A customer desiring the premium service subscribes to two CARs, one reserved exclusively for the premium service, and the second CAR for all other traffic while allowing for some differentiation for traffic using the second CAR. Once packets sent by the CPE router hit the WorldCom network, the edge router looks at the dataflow per the subscribed CAR and how the packets are marked before affixing an MPLS label onto the packets. From then on, it's all MPLS switching using Cisco routers supporting BGP MPLS VPNs, as specified in RFC 2547, WorldCom officials say.

WorldCom claims that while it continues to see growth for its frame relay service, and even some growth in leased lines, it expects MPLS to rev up fast. "MPLS is going to grow quickly and at some point you'll see a decline in frame relay," says Crabtree. "We're definitely targeting the Fortune 500 customers but really where we're seeing the majority of customers for Private IP are the SMBs, many with 20 to 30 sites, but we're also selling to customers that might have just five sites or hundreds of site," Crabtree says.

At the same time, Crabtree notes, MPLS VPNs might not be suitable for those customers that use frame relay in a typical hub-and-spoke topology to connect branch sites to the data center. While this may hold true for those customers that use frame relay for data, it doesn't apply to a customer like Putnam Lovell which has replaced three network services with an IP network and wants the full meshing enabled by MPLS for its voice and video conferencing applications. O'Connor says the attraction of Private IP was that whereas previously the company was doing data over frame relay, voice over circuit-switched connections, and video over ISDN lines, it has now combined all three over IP.

And Putnam Lovell hasn't gotten fancy by taking advantage of the four CoS capabilities offered by Private IP. All of the company's traffic uses a single CoS, and it's not WorldCom's premium service. Still, O'Connor has been especially pleased with moving the company's video conferencing traffic off ISDN to IP. "We used to have horrendous issues with ISDN reliability, especially with trans-Atlantic calls," he says. The company found that with ISDN the quality of a video call would degrade after about a minute and might get dropped all together after about 10 minutes. Putnam Lovell typically was doing video over ISDN at 384 kbps and 512 kbps, and O'Connor figures that the poor quality of the service was due in great part to the fact that various bearer channels were routed differently. "During high peak periods, the couple of hours in the morning when everybody else also wants to video conference, it was just horrible for us," says O'Connor, noting that about 40 percent of ISDN-based video calls failed when mul tiple sites were involved. "I've not had any complaints since moving video onto IP. Even with frame relay you expect some outage at some location every six months, but there's remarkably been no outage with Private IP even though it's a new product of WorldCom."

Putnam Lovell is continuing to use circuit-switched voice as a back-up service, so should a voice call fail, the company's PBXs would route the next call via the PSTN. And with the savings from Private IP, the company has also quickly been able to recoup--in five months--the money it spent on consulting services needed in connection with the move to Private IP and to upgrade routers at some of the locations. That existing customers such as Putnam Lovell, which was using WorldCom for both its frame relay and long-distance voice services, might dump existing services in favor of MPLS VPNs isn't a big concern for WorldGom. "People went to frame relay from private lines because it was cheaper to do so. MPLS is the next logical progression; the technology is out there and it's what customers are looking for," Crabtree says.

Sam Masud, senior technology editor

smasud@telecommagazine.com

COPYRIGHT 2002 Horizon House Publications, Inc.
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