MPLS Forum Hopes to Add Quality of Service to Internet Protocol
Sixteen leading networking and telecommunication companies this week announced the formation of The MPLS Forum, an industry-wide association whose mission is to accelerate interoperability and deployment of MultiProtocol Label Switching (MPLS) and its associated technologies. The MPLS protocol is a critical component for extending best-effort IP networks to include support for traffic engineering, quality of service (QoS) and virtual private networks (VPN).
What MPLS offers is a technology to help IP carry time-critical data such as voice traffic or even video traffic. Today IP is a best-effort medium. This is evidenced by the browser you are reading this by: it is festooned with a Stop and a Reload (resend) button which are often used when a TCP/IP timer somewhere down the line has stopped the data that you are expecting. With an IP voice call it is not practical to stop and resend the last four syllables of conversation, so a method to QoS to the network is necessary.
MPLS roots
MultiProtocol Label Switching is an outgrowth of a proposal by <%=company%> (San Jose, CA) called Tag Distribution Protocol or Tag Switching; itself a competitive response to an almost forgotten technique call IP Switching created by a startup company Ipsilon Networks. Dating back to the dark ages of the World Wide Web (early 1996), the company's solution implemented IP routing software directly on an asynchronous transfer mode (ATM) switch. Ipsilon's IP Switch used its routing software for short-lived data flows and its ATM hardware for long-duration flows, which comprise a large percentage of Internet traffic.
The result is essentially an IP router that had been hotrodded with ATM silicon that handled connectionless datagrams and worked much the same as any conventional router. While the concept of IP Switching was remarkable in its simplicity, it also throws away nearly all of the ATM Forum's standard protocols, making it more than just a bit controversial. The fact that it potentially could replace all the Cisco routers in the Internet made it more controversial.
The IP Switch didn't fly for a number of reasons. The company as eventually acquired by Nokia Corporation (Espoo, Finland) and the concept of IP Switching forgotten. But it did provide the impetus for MPLS, which is now getting closer to practical application. MPLS has the same goal as the original IP Switching in that it seeks to reduce or eliminate as much as possible the processing of each packet at Layer 3 of the network architecture. This processing is the Layer 3 routing table lookups that make routers so much slower than backbone switches.
How MPLS works
In basic terms, MPLS is a software solution to allow routers and ATM switches to apply "labels" to packets as they enter the network and then switch those packets based on the labels. The technology is optimized for very large backbones, like the Internet. Like IP Switching it starts with ordinary routing protocols to lay out paths through the network. But instead of identifying flows, any coherent set of packets leading to the same destination is given the same "label."
The MPLS protocol maintains tables in each node that associates the labels with their destinations. As each packet enters the network, a router does the Layer 3 processing and assigns each packet a label. At any subsequent nodes, Layer 3 processing is bypassed and packets are forwarded solely on the information contained in the label. This holds true whether the subsequent nodes are routers, ATM switches or frame relay switches. In this way MPLS eliminates routing hops from the interior of the network.
The bottom line for IT managers is that there will be a way to control the quality of service of new applications such as virtual private networks or voice over IP that are supposed to run over public IP networks. But it hinges on the acceptance of MPLS technology, a major goal of the new forum.
Getting started
The MPLS Forum has scheduled the first Technical Committee meetings for April 3-4, 2000 at the Sheraton San Jose Hotel in Milpitas, CA. There will be an open session of the committee meeting on April 3 starting at 3:30 p.m. and continuing on April 4 at 8:30 a.m. to allow non-member companies to learn more about the Forum and the activities of the Technical Committee. Companies interested in joining The MPLS Forum are encouraged to participate in this free open session.
The founding members are from the communications software, equipment manufacturer and network service provider communities and comprise: Broadband Office (Vienna, VA), Data Connection Ltd. (Middlesex, UK), Ennovate Networks (Boxboro MA), George Mason University Advanced Internet Lab (Fairfax, VA), GlobeSpan Semiconductor (Red Bank, NJ), Harris & Jeffries (Dedham, MA), Integral Access (Oak Brook, IL), Inverness Systems (Marlborough, MA), Nokia High-Speed Access Products, Lucent Technologies (Murray Hill, NJ), Marconi plc (London), Qwest Communications (Denver), Telcordia Technologies (Morristown, NJ), Tenor Networks (Acton MA), Valient Networks, and Vivace Networks (San Jose, CA).
The MPLS Forum will act as a liaison to provide inputs to the appropriate national and international standards bodies including the IETF, the ITU, the ATM Forum and the Frame Relay Forum.
The Executive Committee, as elected at the founding members meeting on January 28, 2000 at the ComNet 2000 tradeshow, is comprised of:
- David Drury (Marconi plc) as president and chairman
- Andrew Malis (Lucent Technologies) as vice chairman and Technical Committee chair
- Ian Mashiter (Ennovate Networks) as secretary
- John Fryer (Harris & Jeffries) as treasurer along with
- Paul Doolan (Ennovate Networks) and Robert Newcomb (Inverness Systems) as joint chairs of the Marketing and Education Committee.
For more information about The MPLS Forum or the upcoming Technical Committee meetings, please contact Alexa Morris, MPLS Forum Executive Director, at 510-608-5914 or via e-mail at amorris@mplsforum.org. Additional information regarding Forum membership and the Forum's mission is available on The MPLS Forum web site found at http://www.mplsforum.org/.
By: John Spofford, Managing Editor, Premises Networks Online