SONET Bidirectional Line-Switched Ring Equipment Generic Criteria

Transcription

1 Contents SONET Bidirectional Line-Switched Ring Equipment Generic Criteria Contents Contents 1. Introduction Update History Scope Criteria Requirement Labeling Conventions Numbering of Requirement and Related Objects Requirement, Conditional Requirement, and Objective Object Identification Organization Source Documents Assumptions Definitions, Terminology, and Common Phrases Overview of the BLSR Architecture Two-Fiber BLSR Overview Four-Fiber BLSR Overview VT-Access Overview Extra Traffic Overview Squelching to Avoid Misconnected Traffic Enhanced Non-preemptible Unprotected Traffic (E-NUT) Overview STS Squelching Logic Overview Squelching for Unidirectional (and Bidirectional) Circuits Squelching for Multiply Sourced/Dropped Unidirectional Circuits Ring Interworking Overview Drop-and-Continue Method Protection Switching Mechanisms for Inter-ring Traffic Interconnection Survivability with Drop and Continue on Working BandwidthChannels Interconnection Survivability with Drop and Continue on Protection Bandwidth (Ring Interworking on Protection) Cable Cut in Ring #1 and Ring # Primary Node Failure in Ring #1 and Cable Cut in Ring # Dual Transmit Method Dual Transmit On Working Channels Dual Transmit On Protection Channels vii

2 GR 1230 CORE Contents 4. Network Applications Functions Needed for NE Deployment in a BLSR Equipment Criteria and K1/K2 Byte Protocol Equipment Criteria Equipment Criteria for 2- and 4-Fiber Ring Equipment Criteria for 4-Fiber BLSRs Only Equipment Criteria for 2-Fiber BLSRs Only Switch Initiation and K1 and K2 Protocol Switch Initiation Criteria Externally Initiated Protection Switching Commands (OS or WS) Automatically Initiated Protection Switch Requests Functional Requirements Bit-Oriented Protocol for K1/K2 Bytes Steady State Behavior State Transition Rules Examples of Protection Switching in a BLSR Requirements for Ring Interconnection Ring Interconnection Using Protection Capacity Dual Transmit Method Operations, Administration, Maintenance, and Provisioning (OAM&P) Criteria Operations Data Networking Alarm Surveillance Requirements Troubles in the APS Channel Additional Information Needed in BLSR BLSRs and Routine Operations Performance Monitoring (PM) Testing and Control Functions Memory Administration System Availability Criteria Synchronization Criteria Requirement-Object List...ROL 1 Requirement-Object Index... ROI 1 References... References 1 Acronyms... Acronyms 1 viii

3 List of Figures List of Figures Figures Figure 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 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 #1 for Traffic from Node 4 to Node Figure 3-9. Misconnection for STS-1 #1 for Traffic from Node 2 to Node Figure Misconnection for STS-1 #2 for Traffic from Node 3 to Node Figure Misconnection for STS-1 #3 for Traffic from Node 4 to Node Figure Isolation of Two Nodes by a Cable Cut Figure Simplified Node in a 4-Fiber BLSR Figure Node, 4-Fiber BLSR Figure Unidirectional Span Failure on a 4-Fiber BLSR Figure Cable Cut on a 4-Fiber BLSR Figure Restoration for a Cable Cut on a 4-Fiber BLSR Figure Cable Cut and a Span Switch on a 4-Fiber BLSR (Before a Ring Switch) Figure Misconnection of Traffic Related to Existing Switches Figure VT Squelch Table Example (Bidirectional Traffic) All Nodes VTaccess Figure VT Squelch Table Example (Unidirectional Traffic) Not All Nodes VTaccess VT Squelch Table Example (Inter-Ring Capability) All Nodes VTaccess Figure Example of Potential for Misconnection Figure Signalling during SF-R with Extra Traffic Figure Signalling during SF-S with Extra Traffic Figure Conceptual Representation of a E-NUT Table Figure Unidirectional Circuit Squelching Example Where the Failure is in the Opposite Direction from the Unidirectional Circuit Figure Unidirectional Circuit Squelching Example Where the Failure is in the Direction of the Unidirectional Circuit Figure Bidirectional Circuit Squelching Example Figure Multiply Sourced Unidirectional Circuit Squelching Example where the Failure is in the Opposite Direction from the Unidirectional Circuit ix

4 GR 1230 CORE List of Figures Figure Multiply Dropped Unidirectional Circuit Squelching Example where the Failure is in the Opposite Direction from the Unidirectional Circuit Figure Multiply Sourced Unidirectional Circuit Squelching Example where the Failure is in the Direction of the Unidirectional Circuit Figure Multiply Dropped Unidirectional Circuit Squelching Example where the Failure is in the Direction of the Unidirectional Circuit Figure Bidirectional Circuit Squelching Example with Multiply Sourced and Multiply Dropped Traffic Figure Baseline Ring Interconnection Figure Interconnection of BLSR and Mesh Network Figure Correlation Between Inter-ring Circuit and Multiply Sourced and Multiply Dropped Circuits Figure Squelch Table Example for Inter-ring Traffic with Secondary Circuit on Working Bandwidth Figure Ring Interworking on Protection Figure Opposite-Side Routing with (1) Service Circuit on Protection and (2) Service Circuit on Working: Double Link Failures Figure Squelch Table Example for Inter-ring Traffic with Secondary Circuit on Protection Bandwidth Figure RIP Table Example for Inter-ring Traffic with Secondary Circuit on Protection Bandwidth Figure Primary Node Failure Restoral in a BLSR with Secondary Circuit on Protection: Basic Operation Figure Link Failure Restoral in a BLSR with Secondary Circuit on Protection: Optional Enhanced Operation Figure Cable Cut in Ring #1 and Ring # Figure Primary Node Failure in Ring #1 and Cable Cut in Ring #2 with Optional Enhanced Operation Figure Primary Node Failure in Ring #1 and Cable Cut in Ring #2 with Basic Secondary Node Operation Figure Dual transmit Ring Interworking - Relieved Congestion P-S Figure Dual Transmit Ring Interworking - Improved Bandwidth Efficiency Figure BLSR Interconnection with Dual Transmit and Same Side Routing Figure BLSR Interconnection with Dual Transmit and Opposite Side Routing 3 61 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 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) x

5 List of Figures Figure 6-8. Two- or Four-Fiber BLSR - Unidirectional SD (Ring) Figure 6-9. Two- or Four-Fiber BLSR - Node Failure Figure Two- or Four-Fiber BLSR - Node Failure (Concluded) Figure Four-Fiber BLSR - Unidirectional Signal Fail (Ring) Pre-empting a Unidirectional Signal Degrade (Span) on Non-Adjacent Spans Figure Four-Fiber BLSR - Unidirectional Signal Fail (Ring) Pre-empting a Unidirectional Signal Degrade (Span) on Non-Adjacent Spans (Concluded) 6 68 Figure Four-Fiber BLSR - Unidirectional Signal Fail (Ring) Pre-empting a Unidirectional Signal Degrade (Span) on Adjacent Spans Figure Four-Fiber BLSR - Unidirectional Signal Fail (Ring) Pre-empting a Unidirectional Signal Degrade (Span) on Adjacent Spans (Concluded) 6 71 Figure Four-Fiber BLSR - Unidirectional Signal Fail (Span) Pre-empting a Unidirectional Signal Fail (Ring) on Adjacent Spans Figure Two- or Four-Fiber BLSR - Unidirectional Signal Fail (Ring) Plus Unidirectional Signal Fail (Ring) on Non-Adjacent Spans Figure Two- or Four-Fiber BLSR - Node Failure on a Ring with VT access Figure Two- or Four-Fiber BLSR - Node Failure on a Ring with VT access (Concluded) Figure Two- or Four-Fiber BLSR - Node Failure on a Ring with VT access and Extra Traffic Figure Two- or Four-Fiber BLSR - Node Failure on a Ring with VT access and Extra Traffic (Concluded) Figure 7-1. Interconnection between Two BLSRs (Same-side Routing) Figure 7-2. Interconnection between Two BLSRs (Opposite-side Routing) Figure 7-3. Primary Node Failure on a BLSR Figure 7-4. Interconnection of a BLSR with a UPSR Figure 7-5. Service Selection in the Presence of STS PDI-P and STS-SD Figure 8-1. Protection Switch Counts: 2-Fiber BLSR Figure 8-2. Protection Switch Counts: 4-Fiber BLSR Figure 8-3. Squelch Table Example (Based on Table 3-1) xi

6 GR 1230 CORE List of Figures xii

7 List of Tables List of Tables Tables Table 3-1. Traffic Assignments on a 2-Fiber BLSR Table 3-2. Interconnection Options Between Two BLSRs Table 6-1. K1 Bit Assignments Table 6-2. K2 Bit Assignments Table 6-3. Relationships Between K2 Bit 5 and K1 Bits Table 6-4. Byte K1 and K2 Values Sourced in the Idle State Table 6-5. Default APS Codes Table 6-6. Byte K1 and K2 Values Sourced in the Switching State Table 6-7. SD-P and SF-P (LP-S) Coexisting with Ring Switches on the Same Span Table 7-1. Hierarchy of Conditions for Service Selection xiii