Ms-Spring Protection - Alcatel 1850 TSS-320 Technical Handbook

3.6.5 MS-SPRING protection

(See from Figure 73. on page 125 to Figure 78. on page 128)
The following protection MS-SPRING is supported:
– 2 fibers MS-SPRING at STM-16 (VC4 level)
– 2 fibers MS-SPRING at STM-64 (VC4 level)
The supported MS-SPRING is compliant to the ITU-T Rec. G.841
The MS-SPRING protection is realized in the MATRIX (MT320) card.
A 2 fiber MS-SPRING (Multiple Section-Shared Protection Ring) consist of a set of NEs each equipped
with a two bidirectional port, one for the clockwise and the other for the counter-clockwise. The MS-
SPRING is said "two fiber" because each pair of adjacent NEs is linked by two fibers, one for each
direction.
The MS SPRING protection is an alternative with respect to SNCP. While MS SPRING allows the
connection at the same time on the clockwise and on the counterclockwise direction on the same AU4
that can be inserted and extracted in each span, on the contrary the SNCP connection engages the same
AU4 on both sides for the whole link.
Note: In the following the 2F MS-SPRING at STM16 will be explained; the same description can be
applied to 2F MS-SPRING at STM-64 taking into account that 64 AU-4 are available and that the
bandwidth is divided into two halves of equal capacity called respectively "working" (AU4#1 to AU4#32)
and "protection" capacity (AU4#33 to AU#64).
2 fibers MS-SPRING at STM-16 level
The bandwidth of a 2F MS-SPRING is divided into two halves of equal capacity called respectively
"working" (AU4# 1 to AU4# 8) and "protection" capacity (AU4#9 to AU4# 16). The AU4# 1 is protected
by AU4#9 up to AU4#8 that is protected by the AU4#16. The "working " capacity is used to carry the "high
priority traffic", while the "protection" capacity can be used for "low priority" traffic that is lost in case of
failure. See Figure 73. on page125.
In this release the "low priority" connection are not managed.
The MS SPRING algorithm starts as a consequence of the following Section alarms:
• LOS, LOF, MS AIS, EXBER (B2), SIGNAL DEGRADE (B2)
Alcatel 1850 TSS-320 Rel. 1.1
124/270 8DG 07734 AAAA Edition 01
Technical Handbook Common
Functional Description