This allows Ethernet bridging functions
(required for E-LAN services) in MSPPs to view the SONET network not as a collection
of point-to-point links, but as a shared LAN, which can improve significantly the
efficiency of MSPP bridging implementations.6 For this reason, some carriers have
deployed MSPPs with Ethernet/RPR/SONET for dedicated ring applications. However,
in North America the application of RPR has not gone far beyond this, due, in part, to
some RPR limitations:
?– RPR is confined to a single ring, which limits its use as a general-purpose infrastructure
technology.
?– For a number of reasons, including the complexity of the IEEE 802.17 standard,
multi-vendor interoperability has been slow to develop.
Multi-protocol label switching (MPLS) technology represents an intriguing, if not
obvious, complement to the GFP/VCAT/LCAS protocols. MPLS was born as a way to
speed up forwarding of IP packets; later its connection-oriented properties helped to
provide traffic engineering for IP networks. Now segments of the industry are beginning
to view MPLS for what it fundamentally is??”a switching and transport layer for
IP, Ethernet, and other packet-based protocols.
Pages:
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743