Verizon Business' "customer edge to customer edge" SLA option is available at no additional cost for the company's Private IP (Internet Protocol) customers based in the U.S., with the service planned for other Private IP customers by the end of the year. The customer edge SLA covers network facilities that Verizon Business leases from other telecom providers to gain last-mile access to business customers.

Verizon Business offers a 20 percent credit of the customer's monthly recurring charges if it fails to meet the SLA.

Verizon Business is expanding its SLA options because many customers are moving voice, data and video onto Multi Protocol Label Switching (MPLS) networks, said Mike Marcellin, the company's vice president for global product marketing. "The customers we're working with are looking for as robust guarantees as they can get," he said.

In any month, a Verizon Business customer can invoke either the traditional provider edge SLA or the new customer edge SLA.

The two SLAs differ in some details, with the provider edge SLA offering stronger guarantees in some areas. For example, the provider edge SLA guarantees jitter rates of no more than five milliseconds, and the customer edge SLA offers jitter rates of less than 10ms one-way voice over IP traffic and less than 20ms one-way video traffic.

"If it goes off of our private IP network, we lose some level of control, but we're still able to stand behind the overall end-to-end SLA," Marcellin said. "We're giving the customer the best of both worlds."

The customer edge SLAs also offer guarantees on packet delay and packet delivery ratio, as well as time-to-repair guarantees.

Verizon Business has announced other enhancements to its SLAs in the past year, including a voice quality SLA and an enhanced time-to-repair SLA, that did away with the standard average time-to-repair metric in favor of guaranteed time-to-repair in every outage.

The expansion of SLAs are important for customers as they move more applications to wide area networks, said Courtney Munroe, vice president with IDC.

"It's a bid deal in the sense that a lot of [customers] keep asking for more and more tangible SLAs," Munroe said. "A lot of [providers] shy away from giving these SLAs."

Verizon Business' SLAs are among the best in the telecom industry, Munroe said.