* Readers help to clarify AT&T's MPLS strategy
* MCI enables customers to mix IP VPN, private IP, frame relay and ATM nets
* MCI details enhancements plans to its VoIP offerings around the world
* Testing of IPv6 was carried out on Moonv6
* Issues you face if your ISP is sold or changes business strategy
* Your views on whether MCI could still be viewed as a financially viable company
