Multiplex Section Shared Protection Ring (Ms-Spring) And Bidirectional Line Switched Ring (Blsr); Figure 5-4: Msp/Aps Protection Modes - Eci Telecom XDM-100 General Description Manual

Protection and Redundancy
Figure 5-4 shows a four-fiber star XDM-100 with all links protected. This ensures
uninterrupted service even in the case of a double fault. In this case, the system
automatically performs MSP/APS switching within 50 ms.
5.3.2 Multiplex Section Shared Protection Ring
(MS-SPRing) and Bidirectional Line Switched
Ring (BLSR)
In addition to SNCP and path protection, which may also be implemented in ring
topologies, the XDM-100 supports MS-SPRing and BLSR protection. These modes
may provide bandwidth advantages for some ring-based traffic patterns.
Two-fiber MS-SPRing/BLSR supports any 2.5 Gbps rings closed by the XDM-100
via SAM 16-1 cards, in compliance with applicable ITU-T and Telcordia standards.
These protection mechanisms are fully automatic and are performed in less than
50 ms.
In the MS-SPRing/BLSR modes, the STM-16/OC-48 signal is divided into working
and protection capacity per multiplex section/line. In case of a failure in one
multiplex section/line of the ring, protection is performed by looping back the
affected traffic at both ends of the faulty section using the protection capacity.
MS-SPRing/BLSR is particularly beneficial in ring applications with uniform or
adjacent traffic patterns as they offer significant capacity advantage compared to
other protection schemes.
Figure 5-5 shows an XDM-100 in a two-fiber MS-SPRing/BLSR. In this
configuration, two fibers are connected between each site. Each fiber delivers 50%
of the active traffic and 50% of the shared protection traffic. For example, in an
STM-16/OC-48 ring, 8 x VC-4/STS-3c are active and 8 x VC-4/STS-3c are reserved
for shared protection.
5-6

Figure 5-4: MSP/APS protection modes

ECI Telecom Ltd. Proprietary
XDM® -100
417006-2005-013-A02