Recommendation ITU-T G.987.3 Amendment 2 (05/2021) 10-Gigabit-capable passive optical networks (XG-PON): Transmission convergence (TC) layer specification
Summary
History
FOREWORD
Table of Contents
1 Scope
2 References
3 Definitions
4 Abbreviations and acronyms
5 Conventions
6 XG-PON transmission convergence layer overview
     6.1 XGTC layer structure
     6.2 XGTC sublayer functions
          6.2.1 XGTC service adaptation sublayer
          6.2.2 XGTC framing sublayer
          6.2.3 XGTC PHY adaptation sublayer
     6.3 Management of an XG-PON system
          6.3.1 Embedded OAM
          6.3.2 PLOAM channel
          6.3.3 ONU management and control interface (OMCI)
     6.4 Time division multiplexing architecture
          6.4.1 Overview
          6.4.2 ONU identifier
          6.4.3 Allocation identifier (Alloc-ID)
          6.4.4 XGEM port identifier
     6.5 Media access control
7 Resource allocation and quality of service
     7.1 Principles of downstream and upstream resource allocation
          7.1.1 Forms of traffic descriptor
          7.1.2 Traffic descriptor constraints
     7.2 Dynamic bandwidth assignment overview
          7.2.1 PON DBA abstraction
          7.2.2 DBA functional requirements
          7.2.3 DBA methods
     7.3 Reference model of dynamic bandwidth assignment
          7.3.1 Summary of notation
          7.3.2 Offered traffic load
          7.3.3 Components of assigned bandwidth
          7.3.4 Guaranteed bandwidth assignment
          7.3.5 Rate-proportional assignment of additional bandwidth
          7.3.6 Additional bandwidth assignment based on priority and weights
          7.3.7 Timing control of assigned bandwidth
     7.4 DBA performance requirements
          7.4.1 Stationary bandwidth assignment
          7.4.2 Assured bandwidth restoration time
          7.4.3 DBA convergence time
8 XG-PON transmission convergence layer framing
     8.1 Downstream XGTC framing
          8.1.1 HLend structure
          8.1.2 BWmap partition
               8.1.2.1 Alloc-ID field
               8.1.2.2 Flags field
               8.1.2.3 StartTime field
               8.1.2.4 GrantSize field
               8.1.2.5 Forced wake-up indication (FWI) bit
               8.1.2.6 BurstProfile field
               8.1.2.7 HEC field
          8.1.3 BWmap construction limitations and parsing rules
               8.1.3.1 BWmap construction limitations
               8.1.3.2 BWmap parsing exceptions
          8.1.4 PLOAMd partition
     8.2 Upstream XGTC framing
          8.2.1 Upstream XGTC burst header
               8.2.1.1 ONU-ID field
               8.2.1.2 Ind field
               8.2.1.3 HEC field
               8.2.1.4 Upstream PLOAM (PLOAMu) field
          8.2.2 Allocation overhead
               8.2.2.1 BufOcc field
               8.2.2.2 CRC field
          8.2.3 Upstream XGTC burst trailer
9 XG-PON encapsulation method
     9.1 XGEM framing
          9.1.1 XGTC payload structure
          9.1.2 XGEM frame header
          9.1.3 XGEM payload format
          9.1.4 Idle XGEM frame
     9.2 XGEM frame delineation
     9.3 SDU fragmentation
     9.4 Mapping of services into XGEM frames
          9.4.1 Ethernet over XGEM
          9.4.2 MPLS over XGEM
10 PHY adaptation sublayer
     10.1 Downstream PHY frame
          10.1.1 Downstream physical synchronization block (PSBd)
               10.1.1.1 Physical synchronization sequence (PSync)
               10.1.1.2 Superframe counter structure
               10.1.1.3 PON-ID structure
               10.1.1.4 PSBd field scrambling
          10.1.2 ONU downstream synchronization
          10.1.3 Downstream PHY frame payload
     10.2 Upstream PHY frames and upstream PHY bursts
          10.2.1 Upstream physical synchronization block (PSBu)
          10.2.2 Upstream PHY burst payload
          10.2.3 Guard time
     10.3 Forward error correction
          10.3.1 Downstream FEC
          10.3.2 Upstream FEC
               10.3.2.1 Shortened last codeword
               10.3.2.2 BWmap considerations
               10.3.2.3 Upstream FEC on/off control
     10.4 Scrambling
          10.4.1 Scrambling of the downstream PHY frame
          10.4.2 Scrambling of the upstream PHY burst
11 PLOAM messaging channel
     11.1 Overview
          11.1.1 PLOAM channel functionality
          11.1.2 PLOAM channel rate limitations
          11.1.3 PLOAM channel robustness
          11.1.4 Extensibility
     11.2 PLOAM message format
          11.2.1 ONU-ID
          11.2.2 Message type ID
          11.2.3 SeqNo
          11.2.4 Message content
          11.2.5 Message integrity check
     11.3 PLOAM message definitions
          11.3.1 Downstream message summary
          11.3.2 Upstream message summary
          11.3.3 Downstream message formats
               11.3.3.1 Profile message
               11.3.3.2 Assign_ONU-ID message
               11.3.3.3 Ranging_Time message
               11.3.3.4 Deactivate_ONU-ID message
               11.3.3.5 Disable_Serial_Number message
               11.3.3.6 Request_Registration message
               11.3.3.7 Assign_Alloc-ID message
               11.3.3.8 Key_Control message
               11.3.3.9 Sleep_Allow message
          11.3.4 Upstream message formats
               11.3.4.1 Serial_Number_ONU message
               11.3.4.2 Registration message
               11.3.4.3 Key_Report message
               11.3.4.4 Acknowledgment message
               11.3.4.5 Sleep_Request message
12 ONU activation
     12.1 Overview
          12.1.1 Definitions
          12.1.2 Causal sequence of activation events
     12.2 Activation mechanism at the ONU
          12.2.1 ONU activation states, timers and counters
          12.2.2 ONU activation state specification
          12.2.3 ONU state diagram
          12.2.4 ONU state transition table
     12.3 OLT support of the activation process
13 OLT and ONU timing relationships
     13.1 ONU transmission timing and equalization delay
          13.1.1 Timing of ONU upstream transmissions
          13.1.2 Timing relationships and quiet window during serial number acquisition
          13.1.3 Timing relationships and quiet window during ranging
          13.1.4 Calculating the equalization delay
          13.1.5 Timing relationships during regular operation
          13.1.6 In-service equalization delay adjustment
          13.1.7 Quiet window implementation considerations
          13.1.8 Fibre distance measurement
     13.2 Time of day distribution over XG-PON
          13.2.1 Notation
          13.2.2 ONU clock synchronization process
          13.2.3 Performance analysis
               13.2.3.1 Equalization delay accuracy
               13.2.3.2  Fibre propagation delay
               13.2.3.3 Internal timing corrections
14 Performance monitoring, supervision, and defects
     14.1 Performance monitoring
     14.2 Defects
          14.2.1 Items detected at OLT
          14.2.2 Items detected at ONU
15 XG-PON security
     15.1 Threat model for XG-PON
     15.2 Authentication
          15.2.1 Registration ID-based authentication
               15.2.1.1 The OLT perspective
               15.2.1.2 The ONU perspective
          15.2.2 Secure mutual authentication options
     15.3 Key derivation
          15.3.1 Cryptographic method
          15.3.2 Master session key
          15.3.3 Derived shared keys
     15.4 XGEM payload encryption system
          15.4.1 Cryptographic method
          15.4.2 Secret key selection
          15.4.3 Initial counter block
     15.5 Data encryption key exchange and activation mechanism
          15.5.1 Overview
          15.5.2 Cryptographic method
          15.5.3 Unicast encryption
               15.5.3.1 Sequence of encryption key exchange and activation events
               15.5.3.2 OLT states and state diagram
               15.5.3.3 ONU states and state diagram
          15.5.4 Downstream multicast encryption
     15.6 Integrity protection and data origin verification for PLOAM
          15.6.1 Cryptographic method
          15.6.2 MIC calculation
     15.7 Integrity protection and data origin verification for OMCI
          15.7.1 Cryptographic method
          15.7.2 MIC calculation
     15.8 Integrity and data origin verification key switching
          15.8.1 Use of the default key
          15.8.2  Key switching for OMCI-based secure mutual authentication
          15.8.3  Key switching for IEEE 802.1x-based authentication
          15.8.4  MIC failure considerations
     15.9 XG-PON systems with reduced data encryption strength
          15.9.1 Effective key length
          15.9.2 Data encryption key format
16 ONU power management
     16.1 Power management configuration and signalling
     16.2 Power management parameter definitions
     16.3 Power management state machine specifications
          16.3.1 ONU state machine
          16.3.2 OLT state machine
     16.4 Management transactions during low power mode
Annex A  Hybrid error correction (HEC) decoding and scrambler sequence
     A.1 HEC decoding
     A.2 Scrambler sequence
Annex B  Forward error correction using shortened Reed-Solomon codes
     B.1 Polynomial representation over Galois field
     B.2 Construction of RS(248, 232) codeword
     B.3 Construction of RS(248, 216) codeword
Annex C  Secure mutual authentication via OMCI
Annex D  Secure mutual authentication based on IEEE 802.1X
     D.1 Introduction
          D.1.1 Network model for authentication in [IEEE 802.1X]
          D.1.2 Credentials for XG-PON authentication with [IEEE 802.1X]
     D.2 Stack model for XG-PON authentication using [IEEE 802.1X]
     D.3 Behaviour at network entry
Annex E  PON-ID maintenance
     E.1 Introduction
     E.2 PON-ID structure
Annex F  Extended rogue ONU mitigation capabilities
     F.1 Introduction
     F.2 Extra codepoint of disable PLOAM message type
     F.3 Extra transition of the ONU activation cycle state transition diagram
          F.3.1 State transition diagram
          F.3.2 ONU state transition table
Appendix I  Downstream line data pattern conditioning
     I.1 Spectrum control using idle XGEM frames
          I.1.1 Scrambler phase-dependent payload
     I.2 Intentional PON disruption
          I.2.1 Data encryption
          I.2.2 Packet timing control
Appendix II  Time of day derivation and error analysis
Appendix III  Burst profiles
Appendix IV  Golden vectors
     IV.1 Downstream FEC codeword
     IV.2 Upstream FEC codeword
     IV.3 Upstream FEC short codeword
     IV.4 Downstream AES-128 encryption
     IV.5 Upstream AES-128 encryption
     IV.6 Key derivation encryption
     IV.7 Downstream PLOAM message integrity check
     IV.8 Upstream PLOAM message integrity check
     IV.9 Upstream key reporting
     IV.10 Downstream OMCI message integrity check
Bibliography
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