Concert will roll out the service to its PoPs (points of presence) in 35 countries. There are four classes of service defined: two Class 1 services (one for voice, one for interactive data), Class 2 for noninteractive, time-critical applications, such as ERP (enterprise resource planning), and Class 3 for everything else, such as e-mail.

The service will be achieved using Tag VPN, Cisco Systems' implementation of MPLS (Multiprotocol Label Switching). Concert has worked closely with Cisco to automate the configuration process, according to Tony Watson, a senior product manager for Concert. What's particularly interesting is that Concert will also be charging based on CoS. That is, you buy a certain amount of traffic per CoS (in addition to access, CPE and port charges).

Why is CoS important? Because it facilitates deploying robust VoIP (voice over IP) services. The intention, says Watson, is that the service will form the basis of Concert's "one line per customer" strategy. In other words, Concert will be able to run a single IP access line to a customer site and use that one line to support both voice and data traffic.