Enterprise-size organizations for years have been using Multi-protocol Label Switching (MPLS), a type of carrier transport technology that provides a number of efficiencies and cost benefits in the way traffic is carried over wide-area networks. As is usually the case with such services, MPLS has now reached a level of maturity such that it is a viable option for small and medium-sized businesses as well -- and SMBs would do well to consider them.

MPLS enables an SMB to have a single connection to the carrier network from each site over which it can carry all of its voice, data and video traffic. From that single connection, the SMB can connect directly to every other company site, with a high degree of reliability and quality of service control -- the type you don't get with a simple Internet connection.

For companies that are still operating separate voice and data networks, MPLS presents a significant opportunity for network consolidation -- and the resulting cost savings.

As we discussed last week, VoIP is quickly becoming the go-to option for voice service among SMBs, and MPLS makes great sense as a transport. That's because it supplies features that enable customers to dictate which sorts of traffic get priority over others, a concept known as Quality of Service (QoS) or Class of Service (CoS). Real-time services such as voice and video can be guaranteed an uncongested path through the network, while lower-priority traffic such as email and file transfers will be fine with a "best-effort" CoS.

But even the best effort in an MPLS network is far better than what you'd get on the public Internet due to the way packets are routed in an MPLS network. With traditional IP networks, each router a packet passes through has to make a decision on where to pass the packet next. As a result, packets may take a rather circuitous route from point A to B.

With MPLS, the routing decision is made from the start. A short label (the L in MPLS) is affixed to the packet that dictates the route the packet should take through the network. The idea is to always take the fastest route, taking into account any network congestion at that particular time as well as the CoS affixed to the packet. As the packet passes through the network, each router simply passes it along according to the label instructions.

As the M in MPLS implies, the service is also able to carry virtually any traffic using any protocol, from IP to frame relay, ATM and more. It's also used to deliver other services, such as virtual private networks (VPNs) -- a common offering from carriers that makes good sense for SMBs because it provides a level of security you won't get with simple Internet connections.