TABLE OF CONTENTS The prior section of the book was devoted to SONET; in this section we examine the same issues as they relate to the Synchronous Digital Hierarchy (SDH). Many industry papers, books, and references refer to SDH as the international version of SONET; I prefer to view SONET as the North American version of SDH because far more countries rely on the SDH standard than on the SONET standard. That, however, is nothing more than a matter of preference and semantics, so we ll leave it at that.
You will recall from earlier chapters that MCI s Bill McGowan played a major role in the development of the SONET standards. His efforts were also centrally important to the development of SDH.
When McGowan went before the Interexchange Carrier Compatibility Forum (ICCF) to request a standard for mid-span meet following divestiture, the ICCF turned around and sent the petition on to the ANSI T1 Committee. ANSI, founded in 1918, was one of the original standards bodies in the U.S., yet it is unique in that it issues no standards itself; instead, it coordinates, facilitates, and approves standards created by other bodies, most of them in the private sector. ANSI also represents the U.S. at the International Organization for Standardization (ISO).
ANSI comprises more than 300 individual standards bodies as well as a number of industry development groups. Among others, the ANSI organization staffs a number of subcommittees, one group of which falls under the T1 hierarchy. The...
