The growing distributed enterprise requires special consideration when selecting a WAN strategy. Requirements of the branch office should be paramount, considering that without them, you wouldn't need much of a WAN.

So what are the network requirements of branch offices? For users, it’s primarily fast application response time and no downtime. For IT, that means QoS capabilities, redundancy, reliability - and let’s not forget the ability to centrally monitor and manage the network and keep it secure.

Though many companies continue to operate frame-relay and ATM networks, MPLS has emerged as the top technology choice for the majority of midsize to large companies looking to provide reliable networks that can effectively deliver multiple application types.

In fact, 73% report using MPLS in some capacity (either as the WAN technology, or one of their WAN technologies), according to Nemertes’ Advanced Communications Services research benchmark. That’s up from 56% in 2007 and 42% in 2006.

Displacing more costly and less flexible frame relay and ATM services, MPLS has become the de-facto standard for site-to-site connectivity because it has:

* Lower cost (in terms of price and the actual costs for the carriers to operate) when compared with private line, frame-relay or ATM alternatives.
* Native ability to support service guarantees for classes of IP traffic.
* Ability to support any-to-any connectivity, eliminating the need for hub-and-spoke routing architectures.
* Support for services hosted in the carrier network, such as Internet access (often coupled with managed security services) or hosted applications, such voice or video.

Though branch-office proliferation contributes to the decision to use MPLS, the concurrent move toward converged infrastructures also plays a role. Numerous application types with different performance requirements mesh well with MPLS’ ability to classify packets into different priorities.

There are numerous service providers offering MPLS, from the major carriers such as AT&T, Sprint, Qwest, and Verizon, to the emerging carriers, such as Global Crossing, Masergy, and New Edge Networks.

Stay tuned for more details on MPLS differentiators. Nemertes recently completed research, including ratings from 640 carrier customers who rated them on their MPLS services.

Robin Gareiss is executive vice president and senior founding partner of Nemertes Research. Click  here for the newsletter archive.