Multiprotocol Label Switching (MPLS) may be the potion that transforms the public Internet from a best-effort network not good for mission-critical applications to a network that could meet the most stringent business requirements.
But so far, MPLS has not delivered on its promise. Operators and vendors say it is too early to expect significant results, since only a few carriers have implemented the technology and few vendors have standardized on it. MPLS today is just a specification, though the Internet Engineering Task Force is believed to be close to ratifying it as a standard.
In the circa-2000 Internet, MPLS exists as an overlay technology offering the owners better tools for managing their Internet Protocol (IP) networks and their customers' access to premium services.
What network operators do next may define the future of the technology and, to some extent, the future of the Internet. Companies will have to decide between investing in a common infrastructure with no immediate returns - Internetwide deployment of MPLS and peering MPLS traffic - or investing in a particular project with a clearly defined goal - building a for-profit MPLS overlay network. Either option could terribly slow the Net's development for the next 30 years, or boost the medium's potential to new heights, depending on who is talking.
What is MPLS?
MPLS , a technology hatched in cisco systems' labs in 1996 as Tag Switching, enables carriers to route traffic while taking into account the nature of the traffic. The basic principle is that each IP packet is identified according to the type of information it carries - a telephone conversation, a videoconferencing bridge or a rush e-mail message. Based on this, identification routers "know" which traffic has priority and regulate the traffic flow accordingly.
It may be possible to deploy MPLS across the entire fabric of the Internet because all Web traffic is routed. Setting up identification rules as well is just around the corner, since MPLS is about to become a standard. Once the standard is established, all devices running the protocol would know what each packet identification stands for.
Since MPLS is a labeling protocol, not a routing protocol like Border Gateway Protocol, it can work over any kind of data network. It could provide much needed end-to-end continuity for the Internet as it rides over networks that are modern or antiquated, slow or fast. But that scenario can only play out if network operators agree to include MPLS in their peering arrangements.
By engineering peering exchanges to support the labeling protocol, network operators could answer users' pleas for application-specific, dependable performance. Today, carriers peer their networks, or barter long-distance traffic, based on volume. The introduction of MPLS suggests carriers would have to begin exchanging videoconferencing traffic for videoconferencing traffic, voice for voice or perhaps renegotiate deals based on which company is sending best-effort traffic and which is sending "premium" traffic.
Since the IETF has not addressed MPLS peering on the industrywide level, many engineers say the need to establish such a setup is a no-brainer.
