Managed LAN services aren't for everyone, however. For companies that require immediate fixes to LAN problems, for example, having an outside party manage the LAN may be less than ideal. Pazour says that while Verizon Business works as quickly as possible to fix problems in the system, it still takes time for IT workers on his staff to report problems.

"You can't make changes on fly," he says. "You have to submit a trouble ticket, so it does create some delays. In a way it's a bad point, but there are both drawbacks and advantages to it. There's checks and balances in place to make sure that the network is up and running."

Lazar says another potential downside is the complexity of negotiating a managed LAN contract, as companies have to cover a lot of different bases to set parameters for both service quality and application management. Additionally, companies with a large international presence might have trouble finding one managed LAN vendor that can service branches all across the world and many companies will likely have to go with more than one vendor, he says.

"First and foremost, companies should cast a wide net and look at a wide variety of providers," he says. "As a rule during negotiations, you want to tell the vendor everything that's important to you, such as your criteria for success. Obviously, if the provider doesn't know how to handle voice services, then that's a mismatch."

Finally, companies should think long and hard about whether they really need to have a carrier manage their LAN for them, or whether they simply need a good LAN management tool that they can use to manage the LAN themselves. Small businesses with few branch locations and relatively simple LAN demands in particular might want to think twice before paying an outside party to take over their LAN management duties. Curt Benton, the president of fine art print house Pixel2Canvas in Lake Forrest, Calif., uses XRoads Networks' Edge WAN and Internet Load Balancer to ensure network uptime and to add incremental bandwidth during peak hours.