In this article, we describe our experiences in implementing an experimental wide-area GMPLS network called CHEETAH (Circuit-Switched End-to-End Transport Architecture). The key concept is to add a complementary end-to-end circuit based service with dynamic call-by-call bandwidth sharing to the connectionless service already available to end hosts via the Internet. The current CHEETAH experimental network consists of off-the-shelf GMPLS-capable SONET switches (with Ethernet interfaces) deployed at three locations, Research Triangle Park, North Carolina, Atlanta, Georgia, and Oak Ridge, Tennessee. We describe our solutions to various problems relating to control-plane design, IP addressing and control-plane security. We designed and implemented a CHEETAH software package to run on Linux end hosts connected to the CHEETAH network. Among other functions, this software package includes an RSVP-TE module to enable end users and applications to dynamically initiate requests for dedicated en...