White Paper Abstract:
This paper discusses that large inter exchange and some metro service providers leverage four fiber BLSR technology (Telcordia GR-1230-CORE) for their interoffice facility networks. BLSR networks, with their inherent ability to efficiently support distributed traffic patterns, plus the extended restoration that four fiber BLSR provides, proves ideal for IOF networks carrying large amounts of mission-critical traffic. Four-fiber BLSR networks, although requiring double the fiber of a two-fiber BLSR restoration scheme, service providers gain twice the bandwidth capacity per span with a significant increase in reliability through the support of both span switching and ring switching upon a nodal failure. Figure 1 shows a high-level view of a four-fiber BLSR configuration.