A 2-Fiber Multiplex Section Shared Protection Ring (MS-SPRing) / Bidirectional Line-Switched Ring (BLSR) is a ring network of nodes
interconnected by a pair of optical fibers. MS-SPRing/BLSR traffic protection provides 100% restoration of restorable traffic for single failures by reserving 50% of the ring’s capacity for protection. As a result, a 2-Fiber STM-16/OC-48 ring effectively has a span capacity of STM-8/STS-24.
For a 2-Fiber MS-SPRing/BLSR operating at the STM-16/OC-48 level, time slot numbers 1 through 8 (SDH) or 1 through 24 (SONET) at the multiplex input are reserved for working channels. Time slot number ‘X’ of the first fiber is protected using time slot number ‘X+8’ (SDH) or ‘X+24’ (SONET) of the second fiber in the opposite direction, where X is an integer between 1 and 8 (SDH) or between 1 and 24 (SONET).
In a MS-SPRing/BLSR, switching nodes communicate to each other through K-bytes. All of the VC-4s/STS-1s within the line are protected together.
A maximum of 16 NEs is supported for each MS-SPRing/BLSR ring
configuration. The traffic protection switch time is less than 50 ms for rings of up to 1200 km of fiber (ring circumference).
Table 6-12:
SNCP/UPSR protection - command hierarchy
Switch request Priority
Lockout of protection 1 (Highest)
Forced switch 2
Auto switch (P-AIS, P-LOP, P-UNEQ) 3
Auto switch (P-SF) 4
Auto switch (P-SD) 5
Manual switch on protection path 6
Manual switch on working path 7
Wait-to-Restore 8 (lowest)
OAM&P description 6-35
Provisioning MS-SPRing/BLSR protected configurations
The user performs protection group provisioning from the MS-SPRing/BLSR application in the Configuration main menu of the Node Manager (WUI). The user creates the MS-SPRing/BLSR protection group for the STM-16/OC-48 interfaces located on the 1x2.5G+4x155M/2x622M aggregate cards.
East and west ports provisioning
There is no fix mapping between the two ports (east and west) of a MS-SPRing/BLSR traffic protection group. The east and west ports of a protection group must have the same rate and they are provisioned with the following rules:
• STM-16/OC-48 interfaces on the 1x2.5G+4x155M/2x622M aggregate cards:
— protection group members: slot 6 port 1 and slot 7 port 1
— one MS-SPRing/BLSR configuration is supported on the 6130 with STM-16/OC-48 interfaces
Attention: MS-SPRing/BLSR is only supported on the STM-16/OC-48 interfaces of the 1x2.5G+4x155M/2x622M aggregate cards.
Ring map provisioning
The Ring map contains an ordered list of up to 16 APS IDs, ranging in value from 0 to 15 (APS ID0;APS ID1;APS ID2;…;APS ID15). Although ordered, the list does not have to be in sequential order of 0 to 15.
Node ID, Ring ID and WTR Time provisioning
Each NE in the ring must have a unique Node ID number (i.e. APS ID) from 0 to 15. The user also provisions the Ring ID identifier of the MS-SPRing/BLSR configuration. The reversion mode for the MS-SPRing/BLSR configuration is always revertive and the Ring WTR time period is user configurable from 1 to 12 minutes (default value is 5 minutes).
For detailed procedures for MS-SPRing/BLSR protection, refer to Provisioning and Protection Switching Procedures, 323-1855-310.
Cross-connect provisioning for MS-SPRing/BLSR
The user performs cross-connect provisioning from the Cross-connect application in the Configuration main menu of the Node Manager (WUI). The user provisions a 2WAY connection type at the end points and any pass through nodes if applicable. For dual feed applications on MS-SPRing/BLSR configurations, use the 1WAY connection type to create drop-and-continue connections.
For MS-SPRing/BLSR connections only, the MS-SPRing/BLSR end points must be identified. The MS-SPRing/BLSR end points are the APS IDs of the connection end points.
The 6130 supports nodal provisioning. When provisioning an end-to-end circuit, you must provision the traffic protection and cross-connects at the end points and at any pass through nodes that make up the end-to-end circuit.
The following rates are supported for add/drop cross-connects:
• VC-11/VT1.5, VC-12/VT2, VC-3/STS-1 and VC-4
The following rate is supported for pass-through cross-connects:
• STS-1, VC-4
Attention: STS-3c, VC-4-4c/STS-12c cross-connects are not supported in MS-SPRing/BLSR configurations.
VC/STS MS-SPRing/BLSR with LO VC/VT assignment
6130 supports low order (LO) VC/VT assignment on MS-SPRing/BLSR configurations. Payload connectivity in the MS-SPRing/BLSR configurations is at the STS-1, VC-4 level where the STS-1, VC-4 managed connection can contain LO VC/VT payloads. Individual LO VC/VT payload overheads are not monitored.
In LO VC/VT assigned MS-SPRing/BLSR configurations, users must
provision STS-1 or VC-4 connections at pass-through nodes for the LO VC/VT traffic. This gives a number of distinct advantages to the user:
• less connections for the user to manage
• less, therefore quicker, connection retrievals on pass-through nodes
• interoperability support with STS-1 or VC4 based products LO VC/VT assigned end-to-end connections must have the following characteristics:
• for any given end-to-end LO VC/VT connection, add and drop nodes must be provisioned with LO VC/VT connections and pass-through nodes must be provisioned with STS-1 or VC4 connections for the LO VC/VT traffic
• if one LO VC/VT connection is provisioned within an STS-1 or VC4, then the entire STS-1 or VC-4 must be LO VC/VT assigned
• all LO VC/VT assigned end-to-end connections within an STS-1 or VC-4 channel must terminate (add/drop) at the same node
OAM&P description 6-37
Attention:
Extra traffic is not supported with 6130 Release 5.0.
Enhanced non-preemptible unprotected traffic (ENUT) feature is not supported with 6130 Rel 5.0.
For detailed procedures for MS-SPRing/BLSR co5.0nnection provisioning, see Bandwidth and Data Services Procedures, 323-1855-320.
MS-SPRing/BLSR protection switch types
MS-SPRing/BLSR protection switch requests can occur automatically by the system or by user initiated actions. All user-initiated MS-SPRing/BLSR switching commands are signaled on the APS channels (K1 and K2 bytes).
Table 6-13 summarizes the hierarchy of protection commands.
For detailed procedures, see Provisioning and Protection Switching Procedures, 323-1855-310.