Since 1997 MPLS has been heralded as the mother of all networking protocols, which would one day make true voice, video, and data convergence a reality. Over the past four years that idea has morphed into proposals calling for MPLS to do virtual private networking (VPN), intelligent optical switching, and 50-millisecond restoration in Ethernet networks. In short, is has become the answer for almost every problem facing the carrier networks.
Many in the industry are worried that this unfocused, catchall approach is simply a reinvention of ATM (see Poll: Is MPLS BS?).
"MPLS is made up of some of the best and worst aspects of our industry," said John McQuillan, co-chair of the NGN conference. “It goes to show that the urge for a do-it-all protocol is still there. But I think we have to resist that urge, since if you look at the history of developing such a protocol you see it hasn’t been successful.”
During a panel presentation and discussion on Thursday, Robert Newcomb, vice president of marketing for the MPLS Forum and former vice president of sales and marketing for Ennovate Networks, acknowledged that MPLS could not be all things to all networks, as he highlighted the current realities of MPLS successes.
“MPLS may not be able to solve every problem in the network,” said Newcomb. “But by this point it could probably solve world hunger." (Appreciative chuckles ensued.)
At a high level, MPLS was originally supposed to bring predictability and reliability to an IP network to differentiate classes of service so that carriers could provide service-level agreements (SLAs) and quality of service (QOS). It also aimed for the convergence of multiple and existing services over the same network. The ultimate promise was that it would also bring operational savings to carriers implementing it, by automating the way bandwidth connections are set up and torn down.
These lofty expectations took root in the development of three key areas: traffic engineering, VPN implementations, and QOS. The question posed at the conference was how well MPLS achieved those goals. The answer is a mixed one.
On the one hand, it has made significant progress in the development of traffic engineering, enabling carriers to automate more efficient provisioning of connections within their networks. Carriers using MPLS for such purposes include big carriers like UUNet and AT&T Corp. (NYSE: T). Several others like Cable and Wireless (NYSE: CWP), Qwest Communications International Corp. (NYSE: Q), and Verizon Communications Inc. (NYSE: VZ) have announced that they plan to deploy MPLS.
Carriers are also starting to use MPLS for VPNs, which allow corporations to set up secure links through public IP-based networks. While Newcomb, who worked for an IP VPN startup,n which has since gone out of business, admits that VPNs haven’t taken off with the gusto that had been anticipated, he says it's now one of the key areas of focus for the MPLS Forum. The number of customers using MPLS-VPNs is still small. Providers like Global One, which launched its VPN service in April 2000; Bell Canada, which started deployments in April 2001; and WorldCom Inc. (Nasdaq: WCOM), which started offering the service in May 2001 have only signed up a few hundred customers each for their services. This pales in comparison to the tens of thousands of Frame Relay customers.
“We haven’t seen as many VPN deployments as we thought we would,” said Newcomb. “I’m not saying that MPLS VPNs are non-existent, they just aren’t on a global scale of deployment yet.”
As for MPLS being used for quality of service, deployments also haven’t taken off yet. In fact, few if any carriers are using MPLS QOS to provide services to customers.
Like other developing technologies, MPLS has had some growing pains. The process of turning it into a standard has been slow. Currently, there are only 10 ratified RFCs from the Internet Engineering Task Force (IETF), the standards body working on the technology. And there are more than 200 proposals. This means that only five percent of the proposals submitted have gone through the standards process.
Because of the lack of standards, there is a lack of interoperability among different vendors’ gear. Companies like Avici Systems Inc. (Nasdaq: AVCI; Frankfurt: BVC7), Cisco Systems Inc. (Nasdaq: CSCO), and Juniper Networks Inc. (Nasdaq: JNPR) have all demonstrated interoperability in research labs; but in reality, carriers deploying MPLS are sticking with single vendors.
The slowdown in capital spending has also slowed down development, because carriers are loath to invest in new technologies in the midst of a recession in their industry.
“I’ve heard more about Frame Relay this week than I have in the past three years,” said McQuillan during his wrapup session at the end of the conference. “It’s a good example of a connection-oriented network, and that seems to be what carriers want and need.”
And, of course, there are the political obstacles that dog every technology. Infighting within the IETF and among other groups like the Optical Internetworking Forum (OIF) and Metro Ethernet Forum, which also have vested interests in MPLS, has contributed to the lack of focus and slow pace of development.
And yet with each passing day, more and more companies dream up different uses for MPLS. The optical equipment companies want to see the development of Generalized MPLS (GMPLS), which will bring packet intelligence to wavelength switching. Metro Ethernet companies want to morph the Layer 3 protocol into a Layer 2 protocol so that they can use it for providing VPNs. They also hope to use MPLS as a way to provide 50 millisecond restoration, a requirement for any network hoping to replace a Sonet-based network. And voice-over-IP vendors push for voice over MPLS. While Newcomb and others involved in the MPLS Forum agree that there are many uses for MPLS, they urge companies to remain focused.
“I don’t mean to be overly critical of MPLS,” said McQuillan. “But I think they should just pick an application and just go with it.”
— Marguerite Reardon, Senior Editor, Light Reading
http://www.lightreading.com Want to know more? This very topic is the subject of a couple of sessions at