Masergy is one of a number of companies now offering what it calls "Global Ethernet" - a WAN service that's Ethernet from end to end, albeit using different underlying transports. We talked to Tony Hurtado, Masergy's global marketing VP, to find out more about the concepts and technologies involved.

How do you go about building a "Global Ethernet" network?

It's to do with your business model and service architecture - for us, that's Ethernet over MPLS. It's all the same seamless network, the core is making it transparent.

The limitation for others is the need to do Ethernet hand-off at the customer's location. Whether you can do seamless hand-off depends on how your network is engineered - whether legacy networks such as ATM are still involved and so on.

What about QoS for real-time traffic?

Five levels of priority is pretty standard for MPLS now - although it wasn't originally so. We can offer up to eight, but we find five is enough for most enterprises.

A lot of service providers will offer one real-time service level, but we found enterprises wanted the ability to see their voice and video performance separately - it's more of a visibility issue than performance.

The problem enterprises have is not prioritisation across the WAN, it's on the local loop. Some solutions strip the headers and lose the prioritisation - it's an issue of having to integrate MPLS into legacy networks.

Does it need CPE?

Global Ethernet relies on intelligence at the edge to deal with the sophisticated services, then the core is just commodity routing. With our own CPE (customer premises equipment) we can sometimes guarantee a service level that the local carrier can't.

And the local loop?

There's a lot we don't use. We don't use DSL in the US because businesses tend to demand T1 and DS3 connections - the demand is for more predictable performance and more bandwidth for real-time traffic, large packets and images, for example.

How about the management aspect?

An advantage of having CPE is we have edge-to-edge visibility. Then we have Network Analyst, which is an embedded web service that lets our customers monitor and manage their network. It's available at no extra cost because we want our customers to do their own management and not call our NOC all the time.

I estimate that 60 to 70 percent of our customers buy our service because of the sense of empowerment that gives them - it's an attractive option, even for those that rarely use it.