MPLS VPN services will be the focus of MPLScon, an MPLS conference in New York next week designed for potential customers of such services.MPLScon runs May 24-27 with the 26th pretty much dedicated to VPN services with sessions from some vendors, some customers and some consultants who help potential customers decide.The attraction of this type of VPN can be that customers can fully mesh any number of sites much the same way they would using a fully meshed frame relay network but without having to buy separate virtual circuits to connect each site. Instead, they buy a single circuit to the provider's network, which then routes traffic to other customer sites.This can streamline networks for customers, but there are subtleties that customers will want to know before buying these services, and sessions at the conference try to address some of these. For instance, IP routing changes including use of border gateway protocol and interior gateway protocols come into play, and there is an entire session dedicated to these and other routing issues.One reason for the growing popularity of MPLS VPNs is the ability to interwork these services with better established frame relay and ATM services. So if a customer has several sites connected to a network via frame relay, it is possible to connect others via MPLS and still have them communicate with each other by virtue of interworking the services within the provider's network. A session outlining various ways this can be done could prove useful to someone evaluating competing services.The conference offers sessions on other key topics including MPLS and its relationship with VoIP services, virtual LAN services based on MPLS and how to secure remote access to MPLS VPNs.For those considering MPLS services, the conference could be a good spot to pick up background and confront vendors with specific questions.