GR 1230 CORE : ISSUE 4

1 Introduction
1.1 Update History
1.2 Scope
1.3 Criteria
1.4 Requirement Labeling Conventions
1.4.1 Numbering of Requirement and Related Objects
1.4.2 Requirement, Conditional Requirement, and
              Objective Object Identification
1.5 Organization
1.6 Source Documents
1.7 Assumptions
2 Definitions, Terminology, and Common Phrases
3 Overview of the BLSR Architecture
3.1 Two-Fiber BLSR Overview
3.2 Four-Fiber BLSR Overview
3.3 VT-access Overview
3.4 Extra Traffic Overview
3.4.1 Squelching to avoid misconnected traffic
3.5 STS Squelching Logic Overview
3.5.1 Squelching for Unidirectional (and Bidirectional)
              Circuits
3.5.2 Squelching for Multiply Sourced/Dropped
              Unidirectional Circuits
3.6 Ring Interworking Overview
3.6.1 Functionality of the BLSR for Inter-ring Traffic
3.6.2 Protection Switching Mechanisms for Inter-ring
              Traffic
3.6.2.1 Interconnection Survivability with Drop and
              Continue on Working Bandwidth
3.6.2.2 Interconnection Survivability with Drop and
              Continue on Protection Bandwidth (Ring
              Interworking on Protection)
3.6.3 Examples of Failure Recovery for Ring
              Interconnections Using RIP
3.6.3.1 Cable Cut in Ring No. 1 and Ring No. 2
3.6.3.2 Primary Node Failure in Ring No. 1 and Cable
              Cut in Ring No. 2
4 Network Applications
5 Functions Needed for NE Deployment in BLSR
6 Equipment Criteria and K1/K2 Byte Protocol
6.1 Equipment Criteria
6.1.1 Equipment Criteria for 2- and 4-Fiber Ring
6.1.2 Equipment Criteria for 4-Fiber BLSRs Only
6.1.3 Equipment Criteria for 2-Fiber BLSRs Only
6.2 Switch Initiation and K1 and K2 Protocol
6.2.1 Switch Initiation Criteria
6.2.1.1 Externally Initiated Protection Switching
              Commands (OS or WS)
6.2.1.2 Automatically Initiated Protection Switch
              Requests
6.2.1.3 Functional Requirements
6.2.2 Bit-Oriented Protocol for K1/K2 Bytes
6.2.2.1 Steady State Behavior
6.2.2.2 State Transition Rules
6.2.2.3 Examples of Protection Switching in a BLSR
7 Requirements for Ring Interconnection
7.1 Ring Interconnection Using Protection Capacity
8 Operations, Administration, Maintenance, and
              Provisioning (OAM&P) Criteria
8.1 Operations Data Networking
8.2 Alarm Surveillance Requirements
8.2.1 Troubles in the APS Channel
8.2.2 Additional Information Needed in BLSR
8.2.3 BLSRs and Routine Operations
8.3 Performance Monitoring (PM)
8.4 Testing and Control Functions
8.5 Memory Administration
9 System Availability Criteria
10 Synchronization Criteria
Requirement - Object List
Requirement - Object Index
References
Acronyms
List of Figures
Figure 2-1 Isolated Node
Figure 2-2 Short and Long Paths
Figure 2-3 Ring Segmentation
Figure 2-4 Service Selector (Interconnection Between Two BLSRs)
Figure 3-1 Traffic Flow Support on a BLSR Ring
Figure 3-2 Simplified Node in a 2-Fiber BLSR
Figure 3-3 4-Node, 2-Fiber BLSR
Figure 3-4 Traffic Assignment Illustration for a 2-Fiber BLSR
Figure 3-5 Dropped and Continued Paths
Figure 3-6 Ring Switching for a Unidirectional Degradation
              on a 2-Fiber BLSR
Figure 3-7 Node Failure on a 2-Fiber BLSR
Figure 3-8 Misconnection for STS-1 No. 1 for Traffic from
              Node 4 to Node 1
Figure 3-9 Misconnection for STS-1 No. 1 for Traffic from
              Node 2 to Node 1
Figure 3-10 Misconnection for STS-1 No. 2 for Traffic from
              Node 3 to Node 1
Figure 3-11 Misconnection for STS-1 No. 3 for Traffic from
              Node 4 to Node 1
Figure 3-12 Isolation of Two Nodes by a Cable Cut
Figure 3-13 Simplified Node in a 4-Fiber BLSR
Figure 3-14 4-Node, 4-Fiber BLSR
Figure 3-15 Unidirectional Span Failure on a 4-Fiber BLSR
Figure 3-16 Cable Cut on a 4-Fiber BLSR
Figure 3-17 Restoration for a Cable Cut on a 4-Fiber BLSR
Figure 3-18 Cable Cut and Span Switch on a 4-Fiber BLSR
              (Before a Ring Switch)
Figure 3-19 Misconnection of Traffic Related to Existing Switches
Figure 3-20 VT Squelch Table Example (Bidirectional Traffic) -
              All Nodes VT-access
Figure 3-21 VT Squelch Table Example (Unidirectional Traffic -
              Not all Nodes VT-access
Figure 3-22 VT Squelch Table Example (Inter-Ring Capability) -
              All Nodes VT-access
Figure 3-23 Example of Potential for Misconnection
Figure 3-24 Signalling during SF-R with Extra Traffic
Figure 3-25 Signalling during SF-S with Extra Traffic
Figure 3-26 Unidirectional Circuit Squelching Example Where the
              Failure is in the Opposite Direction from the
              Unidirectional Circuit
Figure 3-27 Unidirectional Circuit Squelching Example Where the
              Failure is in the Direction of the Unidirectional Circuit
Figure 3-28 Bidirectional Circuit Squelching Example
Figure 3-29 Multiply Sourced Unidirectional Circuit Squelching
              Example where the Failure is in the Opposite
              Direction from the Unidirectional Circuit
Figure 3-30 Multiply Dropped Unidirectional Circuit Squelching
              Example where the Failure is in the Opposite
              Direction from the Unidirectional Circuit
Figure 3-31 Multiply Sourced Unidirectional Circuit Squelching
              Example where the Failure is in the Direction of the
              Unidirectional Circuit
Figure 3-32 Multiply Dropped Unidirectional Circuit Squelching
              Example where the Failure is in the Direction
              of the Unidirectional Circuit
Figure 3-33 Bidirectional Circuit Squelching Example with Multiply
              Sourced and Multiply Dropped Traffic
Figure 3-34 Baseline Ring Interconnection
Figure 3-35 Interconnection of BLSR and Mesh Network
Figure 3-36 Correlation Between Inter-ring Circuit and Multiply
              Sourced and Multiply Dropped Circuits
Figure 3-37 Squelch Table Example for Inter-ring Traffic with
              Secondary Circuit on Working Bandwidth
Figure 3-38 Ring Interworking on Protection
Figure 3-39 Opposite-Side Routing with (1) Service Circuit on
              Protection and (2) Service Circuit on Working:
              Double Link Failures
Figure 3-40 Squelch Table Example for Inter-ring Traffic with
              Secondary Circuit on Protection Bandwidth
Figure 3-41 RIP Table Example for Inter-ring Traffic with
              Secondary Circuit on Protection Bandwidth
Figure 3-42 Primary Node Failure Restoral in a BLSR with
              Secondary Circuit on Protection: Basic Operation
Figure 3-43 Link Failure Restoral in a BLSR with Secondary Circuit
              on Protection: Optional Enhanced Operation
Figure 3-44 Cable Cut in Ring No. 1 and Ring No. 2
Figure 3-45 Primary Node Failure in Ring No. 1 and Cable Cut in
              Ring No. 2 with Optional Enhanced Operation
Figure 3-46 Primary Node Failure in Ring No. 1 and Cable Cut
              in Ring No. 2 with Basic Secondary Node Operation
Figure 6-1 Isolated Node Signaling (Signaling States Before
              B and D Establish a Ring Bridge and Switch)
Figure 6-2 Four-Fiber BLSR - Unidirectional Failure (Span)
              on Working From E to F
Figure 6-3 Four-Fiber BLSR - Unidirectional Failure (Span)
              on Working From E to F (Concluded)
Figure 6-4 Two- or Four-Fiber BLSR - Unidirectional SF (Ring)
Figure 6-5 Two- or Four-Fiber BLSR - Unidirectional SF (Ring)
              (Concluded)
Figure 6-6 Two- or Four-Fiber BLSR - Bidirectional SF (Ring)
Figure 6-7 Two- or Four-Fiber BLSR - Bidirectional SF (Ring)
              (Concluded)
Figure 6-8 Two- or Four-Fiber BLSR - Unidirectional SD (Ring)
Figure 6-9 Two- or Four-Fiber BLSR - Node Failure
Figure 6-10 Two- or Four-Fiber BLSR - Node Failure (Concluded)
Figure 6-11 Four-Fiber BLSR - Unidirectional Signal Fail (Ring)
              Pre-empting a Unidirectional Signal Degrade (Span)
              on Non-Adjacent Spans
Figure 6-12 Four-Fiber BLSR - Unidirectional Signal Fail (Ring)
              Pre-empting a Unidirectional Signal Degrade (Span)
              on Non-Adjacent Spans (Concluded)
Figure 6-13 Four-Fiber BLSR - Unidirectional Signal Fail (Ring)
              Pre-empting a Unidirectional Signal Degrade (Span)
              on Adjacent Spans
Figure 6-14 Four-Fiber BLSR - Unidirectional Signal Fail (Ring)
              Pre-empting a Unidirectional Signal Degrade (Span)
              on Adjacent Spans (Concluded)
Figure 6-15 Four-Fiber BLSR - Unidirectional Signal Fail (Span)
              Pre-empting a Unidirectional Signal Fail (Ring) on
              Adjacent Spans
Figure 6-16 Two- or Four-Fiber BLSR - Unidirectional Signal
              Fail (Ring) Plus Unidirectional Signal Fail (Ring)
              on Non-Adjacent Spans
Figure 6-17 Two- or Four-Fiber BLSR - Node Failure on a Ring
              with VT access
Figure 6-18 Two- or Four-Fiber BLSR - Node Failure on a Ring
              with VT access (Concluded)
Figure 6-19 Two- or Four-Fiber BLSR - Node Failure on a Ring
              with VT access and Extra Traffic
Figure 6-20 Two- or Four-Fiber BLSR - Node Failure on a Ring
              with VT access and Extra Traffic (Concluded)

Defines Telcordia's view on proposed generic criteria for two- and four-fiber Bi-directional Line-Switched Rings (BLSRs). Criteria for BLSR equipment, BLSR basic APS protocol, ring interconnection, and OAM&P are given, including criteria for enhancements to the basic BLSR APS protocol (i.e. extra traffic, VT-access, and support for unidirectional services). Criteria for Dual Transmit and Enhanced Non-preemptible Unprotected Traffic is also included. Tutorial material is also supplied in this GR.