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![97
Layer 2 functions
OMCI supports two major layer 2 traffic mapping
models:
• MAC bridging: described in [IEEE 802.1D] and [IEEE
802.1Q]
• "IEEE 802.1p mapping".
OMCI](https://image.slidesharecdn.com/gponthetechnology-rev1-191226144542/85/Gpon-the-technology-rev-1-97-320.jpg)
![99
IEEE 802.1p mapping
IEEE 802.1p mapper service profile A
managed entity witch associates the priorities
of IEEE 802.1p [IEEE 802.1D] priority tagged
frames with specific connections. This
managed entity directs upstream traffic to the
designated GEM ports.
OMCI](https://image.slidesharecdn.com/gponthetechnology-rev1-191226144542/85/Gpon-the-technology-rev-1-99-320.jpg)
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Gpon the technology --rev 1
- 1. GPON Technology Pushing FiberOptic to the Access Networks
- 2. Quien no conocenada; no ama nada. Quien no puede hacer nada; no comprende nada. Quien nada comprende, nada vale. Pero quien comprende también ama, observa, ve. Cuanto mayor es el conocimiento inherente a una cosa, mas grande es el amor que se le tiene. Anonimo
- 3.
- 4. 4 Bandwidth grow expectations BitMovement will grow significatly next years mainly puched by Video app 1 Petabyte (Pb) = 1015 bytes Google move 20Pb/day
- 5.
- 6. 6 GPON On BRICcountries GPON Equipment Revenue, BRIC Countries and Worldwide GPON Ports, BRIC Countries and Worldwide GPON Revenue ($Millions) CY09 CY10 CY11 CY12 CY13 CY14 CY15 CY16 CY17 BRIC GPON $157 $822 $850 $1,368 $1,394 $1,374 $1,385 $1,393 $1,417 WW GPON $631 $1,489 $1,921 $2,523 $2,516 $2,512 $2,447 $2,464 $2,569 % BRIC 25% 55% 44% 54% 55% 55% 57% 57% 55% GPON Ports (Millions) CY09 CY10 CY11 CY12 CY13 CY14 CY15 CY16 CY17 BRIC GPON 0.8 2.4 6.5 14.5 16.7 18.6 20.3 21.5 22.4 WW GPON 2.4 5.0 11.5 20.1 23.2 25.6 27.6 29.0 30.3 % BRIC 32% 48% 57% 72% 72% 73% 74% 74% 74%
- 7. 7 Cumulative port shipmentsby country • Total BRIC port shipments were up nearly 122% in CY12 • From 2013–2017, cumulative BRIC 2.5G GPON port shipments will top 97 million • The bulk will be on ONTs to directly connect subscribers – Especially in China, where China Telecom and China Unicom are moving from an architecture based on fiber-to-the-building to direct fiber connections in the home in order to achieve stated goals of providing 20M service across their urban footprints 2013–2017 Cumulative 2.5 GPON Port Shipments China Russia Brazil India 2.5G GPON 89M 5.3M 1.9M 0.7M
- 8.
- 9. 9 • Point-to-Point links –Simple, standardized and mature technology – N fiber lines – 2N transceivers A Litle Bit of History
- 10. 10 • Active OpticalNetwork – Simple, standardized and mature technology – 1 fiber line – Curb Switch power in the field – 2N+2 transcievers A Litle Bit of History
- 11. 11 • Passive OpticalNetwork (PON) – “Simple”, standardized technology – 1 fiber line shared between N users. – N+1 transceivers. – passive devices (splitters) as main componets on the street Current Solution
- 12. 12 ODN Optical Data Network OLT:Optical Line Terminator ONU: Optical Network Unit ODN: Optical Distribution Network Elements
- 13.
- 14. 14 Why GPON? GPON（Gigabit-capable PassiveOptical Networks） GPON supports : • Triple－play service • high-bandwidth • long-reach (up to 20 km) • GPON is the choice of large carriers in the international market
- 15.
- 16. 16 ODN OLTONU FTTH 1:64 Fiber Tothe Home Spliter Spliter OLT ONU ONU ONU Scenarios
- 17. 17 FIber OLTONU FTTB/C CopperNT 1:64 Fiber Tothe Business or Fiber to MDU XDSL Node Scenarios
- 18. 18 FIber OLTONU FTTCab CopperNT Fiber ToCabinet 1:64 XDSL Node Cabienet Scenarios
- 19. 19 Logical reach –Logical reach is the maximum logical distance between ONU/ONT and OLT. – In GPON, the maximum logical reach is defined as 60 km. (Delay) Physical reach – Physical reach is the maximum physical distance between the ONU/ONT and the OLT. – In GPON, two options are defined for the physical reach: 10 km and 20 km. Differential fiber distance – In GPON, the maximum differential fiber distance is 20 km. The distance between nearest and farthest ONT
- 20.
- 21.
- 22. 22 Elements A Way toProtect FO 1:64 Spliter Spliter OLT ONU ONU ONU Optical Key Optical Key
- 23.
- 24. 24 Elements Spliters: • Two BasicTypes Fuser Biconical Tapper (FBT) Planar lightwave circuit (PLC)
- 25. 25 10 Log 𝑃0 1𝑚𝑤= P0 𝐷𝑏𝑚 P0 𝑚𝑤 = 3,1 mw = 5 𝐷𝑏𝑚 3,1 mw 1,5 mw 1,5 mw 3 db Lost 5 𝐷𝑏𝑚 Elements Spliters: (FBT) Fuser Biconical Tapper Splitters of this type support three wavelengths (850/1310/1550 nm), and are incapable of operating at other wavelengths
- 26. 26 Elements Spliters: Planar lightwave circuit(PLC) They have a broader operating wavelength range (1260-1650 nm) than low-cost fused biconic tapered (FBT) couplers.
- 27. 27 Planar lightwave circuit(PLC) Fiber Type Single mode G657A1 or G652D Typical Insertion Loss (≤) dB 19.7
- 28. 28 Número de puertos Pérdidade divisor (dB) (excluidas conexiones) 2 3 4 6 8 9 16 12 32 15 64 18 Elements Spliters: Typical Loose Loss = 10 Log {N} N:: Port Quantitie
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- 33. 33 • The greaterthe division ratio, the lower the infrastructure cost per user. • But the division causes energy loss (in an ideal division by N, the loss is 10 log (N) dB (aprox). • Therefore, for a higher division they should be used more power • Components and lower losses, which have a higher cost. • Commercial lasers have power in the range from 0 to 10 dBm • The highest number of users on the network involves reducing the bandwidth available to each. • Studies show 1:40 as the optimal division (J. Wellen, "High-speed FFTH technologies in an open access plataform" in Broadband Optical Access Networks and Fiber to the home, edited by C.Lin, 139-166, John Wiley & Sons, 1995.) • In practice are used ratios of 1:16, 1:32 Division Ratio Elements
- 34. Band Occupancy forGPON and XGPON
- 35. 35 Band Occupancy forGPON and XGPON Optical Fiber Bands and Losses The C-band (Conventional) is the most used for transmission over long distances The peak in the band E is due to water absorption and can be removed in High quality fiber
- 36. 36 Optical Fiber Bands BandOccupancy for GPON and XGPON
- 37.
- 38. Data Multiplexing inGPON Networks Main Characteristics
- 39. 39 • GPON adoptsWavelength Division Multiplexing (WDM) technology, facilitating bi-direction communication over a single fiber GPON Wavelengths windows For Single fiber GPON possible transfer Speeds Data Multiplexing Elements OLT ONUs 1310 nm 1490 nm DownStream UpStream
- 40. 40 • Downstream point-to-multipoint network – The OLT manages the whole bandwidth. • Upstream multipoint-to-point network – ONUs transmit only towards the OLT. – ONUs cannot detect other ONUs transmissions. – Data transmitted by ONUs “may collide”. Need of a channel separation mechanism to fairly share bandwidth resources Up: TD MA Time Division Multiple Access Down:P2P Fo solution Elements Elements
- 41. 41 • Downstream towardthe OLT interleaves frames for different ONUs as a continuous beam and sends in “broadcast” to all ONU. • Each ONU draws its tables based on information in the header. • Upstream toward the OLT, the ONU who is not transmitting switch off its transmitter. • This causes the transmission is in burst mode. • Each frame must have a preamble for synchronization. • A guard time is reserved between frames. Elements Elements
- 42. • To separateupstream/downstream signals of multiple users over a single fiber, GPON adopts two multiplexing mechanisms: • In downstream direction, data packets are transmitted in a “broadcast way” ONU#3 OLT ONU#1 ONU#2 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 Downstream Direction: Broadcast mode On 1490 nm Fiber Optic wavelength Data Multiplexing Elements
- 43. 43 • In upstreamdirection, data packets are transmitted in a TDMA (Time Division Multiple Access) manner. Data Multiplexing Elements 43 3 1 2 3 t1 1 t2 2 t3 Upstream Direction: TDMA mode On 1310 nm Fiber Optic wavelength OLT ONU#1 ONU#2 ONU#3 1 2 3 t0
- 44. The GPON Layers ControlLayer User Layer
- 45. 45 Upper Layers Layer 4 Layer3 Layer 2 Physical PON PHY TDM POTS DATA VIDEO TCP/UDP IP Ethernet GPON Layering Control GEM (Generic Encapsulation Method) GTC-TC Frame (GPON Transmission Convergence frames ) GTC Layer
- 46. 46 • The mostimportant Layer is named Generic Transmission Convergence (GTC) • We can divided the GTC layer in two planes: – The User plane. – The control and management system witch consists of three parts: • embedded OAM, • PLOAM, (Physical Layer Operation and Maintenance) • OMCI. THE GTC LAYER
- 47. GEM Framing Sublayer GEM Adaptation Sublayer OMCI Adapter GEM Adapter DBA Control GPONPMD GPON GTC 47 G-PON Transmission Convergence (GTC) Layer Multiplexing Control an Data Framing, It specifies GPON frame format, the media access control protocol, OAM processes and information encryption method. GTC frame provides the common time reference for the PON and common control signaling for the upstream. “Light Coding” NRZ PLOAM OMCI GEM Client
- 48. GTC Adaptation Sub-Layer GTC Framing Sub-Layer 48 The embedded OAMchannel is provided by field-formatted information in the header of the GTC frame. Some of its functions are: bandwidth allocation, security key switching, and dynamic bandwidth assignment signaling The PLOAM channel is a message- formatted system carried in a dedicated place of the GTC frame. This channel is used for all other PMD and GTC management information that is not sent via the embedded OAM channel The ONU management and control interface (OMCI) channel is used to manage the service-defining layers, which reside above the GTC Protocol stack for the C/M-plane PLOAM OMCI PLOAM Partition Multiplexing based on location withing the frame OMCI adapter Port-ID Filter GEM Adapter ALLOC ID Filter GEM Partition FRAME Header OAM Embeded
- 49. 49 Port-ID and PTI filter GEM Adapter GEMClient ALLOC ID Filter PLOAM Partition GEM Partition FRAME Header Multiplexing based on location withing the frame GTC Adaptation Sub-Layer GTC Framing Sub-Layer In the downstream direction, the GEM frames are carried in the GTC payload and arrive at all the ONUs. The ONU framing sub layer extracts the frames, and the GEM TC adapter filters the frames based on their 12-bit GEM Port-ID. Only frames with the appropriate Port-IDs are allowed through to the GEM client function In the upstream direction, the GEM traffic is carried over one or more T- CONTs (Alloc ID) . The OLT receives the transmission associated with the T-CONT and the frames are forwarded to the GEM TC adapter and then the GEM client Protocol stack for the User-plane
- 50. TCONT GEM PORT CE-VLAN CE-VLAN CE-VLAN Service Ethernet CE-VLAN CE-VLAN CE-VLAN GEM Port UpDown TCONT GEM PORT Ethernet Flow Ethernet Flow EthernetFlow Service Ethernet CE-VLAN GEM Port UpDown TCONT GEM PORT GEM FlowGEM FLOW GEM Port UpDown
- 51. The Down StreamFlow DS Flow
- 52. 52 • Down StreamFlow – GPON Transmission Convergence frames (GTC) are always 125 msec long • 19440 bytes / frame for 1244.16 rate • 38880 bytes / frame for 2488.32 rate – Each GTC frame consists of Physical Control Block downstream (PCBd) + payload • PCBd contains sync, OAM, DBA info, etc. – Will be the Timing base for all ONUs . • Payload may have ATM and GEM partitions (either one or both) GTC Frame payloadPCBd payloadPCBd 125 Usec payloadPCBd 125 Usec The Down Stream Flow
- 53. 53 FEC Ind 1−bit Reserved 1−bit Super−frame Counter 30−bit Blen BWMap Length (12 bit) Alen ATM Partition 12−bit CRC 8−bit Access 1 8 bytes Access 2 8 bytes Access N 8 bytes ………. AllocID 12 bits Flags 12 bits SStart 2 bytes SStop 2 bytes CRC Down Stream (PCBd Structure) pSync 4−bytes Ident 4−bytes PLOAMd 13−bytes BIP 1−byte PLend 4−bytes US BW Map N*8−bytes PCBd Payload 125useg ONU−ID 1−byte Msg ID 1−byte Message 10−bytes CRC 1−byte The Down Stream Flow
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- 55. 55 •The PLOAMd channelsupports the PON TC layer management functions: ONU activation, OMCC (Optical Network Unit Management and Control Channel) establishment. encryption configuration, key management alarm signaling PCBd Payload pSync 4−bytes Ident 4−bytes PLOAMd 13−bytes BIP 1−byte PLend 4−bytes US BW Map N*8−bytes ONU−ID 1−byte Msg ID 1−byte Message 10−bytes CRC 1−byte ITU-T G.984.3 • PLOAMd Typical messages: Upstream_Overhead. Assign_ONU-ID. Ranging_Time. Deactivate_ONU-ID. Disable_Serial_Number. Encrypted_Port-ID. Request_Password Assign_Alloc-ID. No message. Request_Key. Configure Port-ID. Physical_Equipment_Error BER Interval The Down Stream Flow
- 56. 56 • PLOAM MessagesDown Stream Direction (just some messages …!!) – Assign_ONU-ID • To link a free ONU-ID number with the serial number also provided in this message. – Ranging_Time • To indicate the value that the specified ONU must fill into its equalization delay register. – Deactivate_ONU-ID • To instruct an ONU with this ONU-ID to stop sending upstream traffic and reset itself. It can also be a broadcast message. – Disable_Serial_Number • To disable/enable an ONU with this serial number. The Down Stream Flow
- 57. 57 • PLOAM MessagesDown Stream Direction – Assign_Alloc-ID • To instruct an ONU that the specified allocation ID is assigned to it. – Configure Port-ID • This message links the internally processed OMCI channel at the ONU with a 12-bit Port-ID. The Port-ID is appended to the GEM overhead and used as an addressing mechanism to route OMCI over the GEM channel. The Down Stream Flow
- 58. 58 Payload (GEM Packet) HeaderPCBd BW Maps Alloc ID #1 Start 100 End 200 Alloc ID #2 Start 400 End 650 Alloc ID #3 Start 700 End 1000 ID#1 ID#2 ID#3 Upstream Flows Byte 100 Byte 200 Byte 400 Byte 650 Byte 700 Byte 1000 NOTE: Allocation identifier (Alloc-ID) is a 12-bit number that the OLT assigns to an ONU to identify a traffic-bearing entity that is a recipient of upstream bandwidth allocations within that ONU. Such a traffic-bearing entity can be represented either by a T-CONT or by the upstream OMCC. Down Stream (US Bandwidth Maps) The Down Stream Flow
- 59.
- 60. 60 • Up Streamflow. • Physical Layer Overhead upstream (PLOu) – always sent by ONU when taking over from another ONU – contains preamble and delimiter (lengths set by OLT in PLOAMd) BIP (1B), ONU-ID (1B), and Indication of real-time status (1B) • PLOAM upstream (13B) - messaging with PLOAMd • Power Levelling Sequence upstream (120B) – used during power-set and power-change to help set ONU power so that OLT sees similar power from all ONUs • Dynamic Bandwidth Report upstream – sends traffic status to OLT in order to enable DBA computation PLOu PLOAMu PLSu DBRu payload The Up Stream Flow
- 61. 61 PCBu PLOAM PLSuDBRu Payload Preamble “A” bytes Delimiter “B” bytes BIP 1−byte ONU−ID 1−byte Ind 1−byte Up Stream CRC 1−byte DBA 1, 2, 4 bytes The Up Stream Flow
- 62. 62 PCBu PLOAM PLSuDBRu Payload ONU−ID 1−byte Msg ID 1−byte Message 10−bytes CRC 1−byte ITU-T G.984.3 Up Stream (PLOAMu ) •The PLOAM channel supports the PON TC layer management functions, ONU activation, OMCC establishment, encryption configuration, key management and alarm signaling • PLOAMu Typical messages Serial_Number_ONU Password Dying_Gasp No message Encryption key Physical_Equipment_Error (PEE). PST message Remote error indication (REI) Acknowledge The Flow
- 63. 63 • Up Streamflow. Considerations. • GTC fames are still 125 msec long, but shared amongst ONUs • Each ONU transmits a burst of data – using timing acquired by locking onto OLT signal – according to time allocation sent by OLT in BWmap • there may be multiple allocations to single ONU • OLT computes DBA by monitoring traffic status (buffers) of ONUs and knowing priorities – at power level requested by OLT (3 levels) • this enables OLT to use avalanche photodiodes which are sensitive to high power bursts – leaving a guard time from previous ONU's transmission – prefixing a preamble to enable OLT to acquire power and phase – identifying itself (ONU-ID) in addition to traffic IDs (“Port-ID”) – scrambling data (but not preamble/delimiter) The Up Stream Flow
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- 65. 65 • In anODN (Optical Data Network) there is 1 OLT, but many ONUs….So. • ONUs must somehow be labeled for: – OLT to identify the destination ONU. – ONU to identify itself as the source. • GPON has several levels of labels, two of the most relevant are: – For GEM (Generic Encapsulation Method) mode encapsulation: • “GEM” Port_ID (12b). – Transmission-CONTainer or T-CONT : • Alloc_ID (12b) (can be >1 T-CONT per ONU) Data Multiplexing GEM´s and TCON´s
- 66. 66 • GEM Encapsulationmethod and GEM-PORT-ID – GEM is a generic encapsulation method – any packet type (and even TDM) can be encapsulated on it. – GEM supports fragmentation and reassembly. – GEM is based on GFP (Generic Frame Procedure), and the header contains the following fields: • Payload Length Indicator - payload length in Bytes. • Port ID - or GEM-Port ID: identifies the target ONU. • Payload Type Indicator (GEM OAM, congestion/fragmentation indication). • Header Error Correction field (BCH(39,12,2) code+ 1b even parity). 5 B GEM´s and TCON´s Port ID (12b) PLI (12b) HEC (13b) PTI (3b) payload fragment (L Bytes) PLOu PLOAMu PLSu DBRu payload GEM Header Payload GEM Header Payload GEM Header Payload 125useg
- 67. 67 • Original PacketFormat Layer 2 information Layer 3 information Layer 4 information MAC DA MAC SA Length Type IP header TOS ...... IP SA IP DA TCP/UDP Header ...... Data Single Tag Packet Format GEM encapsulated 802.1Q/P Length Type MAC DA MAC SA Length Type IP header TOS ...... IP SA IP DA TCP/UDP Header ...... Data TPID 16 Bits Priority 3 Bits CFI 1 Bits VID 12 Bits PTI Port ID PLI EOF GEM
- 68. 68 The GEM Header.Encapsulating Ethernet on GEM Inter Packet Gap Preamble SFD DA SA Length/Type Data FCS EOF 12 7 1 6 6 2 4 1 PLI Port ID PTI Identify the ONT On Downstream Layering GPON PTI Code Meaning 000 User data fragment, Congestion has Not occurred, Not the end of a frame 001 User data fragment, Congestion has Not occurred, End of a frame 010 User data fragment, Congestion Has occurred, Not the end of a frame 011 User data fragment, Congestion Has occurred, End of a frame 100 GEM OAM 101 Reserved 110 Reserved 111 Reserved GEM Payload Payload for GCT frames GEM´s and TCON´s
- 69. 69 • Traffic Container(T-CONT) – Main meaning: • An Internal ONU Entity that represent the allocation of Upstream Bandwidth at the Transmission Convergence layer ant it is signaled by the OLT. – They only have significance at upstream direction. But are signaled at the downstream direction. – There are at least 1 T-CONT per ONT (Alloc_id materializes the T-CONT concept and could be equal to ONT_id for the first one asigned) • T-CONT “holds” together traffic/port-IDs with “similar characteristics”. • Can be intended as a group of “traffic classes”. – T-CONT´s can be “burst” or not or can be high versus low priority. – “Temporal slots” are spread as needed to guarantee “QoS” parameters. Upstream Flows TCON#1 TCON#2 TCON#3 Byte 100 Byte 200 Byte 400 Byte 650 Byte 700 Byte 1000 ONU#1 ONU#1 ONU#1 Data Multiplexing
- 70. 70 T1 T2 Up StreamFlows TCONTs TCONS at Real Time
- 71. 71 TCONS at RealTime
- 72.
- 73. 73 • The term"activation process" refers to the set of distributed procedures allowing an inactive ONU to join or resume operations on the PON. The activation process includes three phases: – Parameter learning, – Serial number acquisition, – Ranging. Activation process
- 74. 74 • Parameter learningphase, the ONU, while remaining passive, acquires the operating parameters to be used in the upstream transmission. • Serial number acquisition phase, the OLT discovers a new ONU by its serial number and assigns the ONU- ID. – OLT recognizes arrival of an ONT – OLT discovers the Serial Number – OLT assigns ONT_id to ONT • ONU ID: between 0…253 for ONU (254 for broadcast) Activation process
- 75. 75 • Ranging: TheEqD (equalization delay) for each given ONU is computed by the OLT based on the measurement of the corresponding RTD (Round Trip Delay) and is communicated to the ONU during the ranging phase. – OLT measures arrival phase – OLT provides equalization delay – ONT adjusts TX phase • Services can be provisioned Activation process
- 76. 76 • State 1 –The OLT is transmitting valid downstream frames, and the ONU attempts to attain frame synchronization. Once two consecutive frames with a valid PSync value are found, the ONU clears the LOS/LOF error and transitions to State O2. • State 2 – OLT Start transmiting DS overhead PLOAM witch containg “intructions” for ONU build the Overhead for US mesages (paramenter Learning) , example • Number of guard bits • Length of Type 1 Preamble bits • Length of Type 2 Preamble bits • Pattern of Type 3 preamble pattern. OLT ONU State S1 State S2 State S3 Activation process
- 77. 77 • State S3. –Extended_Burst_Length PLOAM message. • Optional. – Pre-SN quiet window (DS Frames with no Bandwith Maps add 200 usec of quite window). – Serial_Number_Request message. – Post-SN quiet window. (add 50usec of quite window) OLT ONU State S1 State S2 State S3 Activation process
- 78. 78 • State S4 –Range_Request message • Range_Request is a BWMap entry, to a specific previously OLT send a quite window message . – Range_Response message • The ONU responds to the Range_Request access with a Range_Response message. The response is the Serial_Number_ONU PLOAM. – Ranging_Time PLOAM message • After sending the Range_Request, the OLT looks for the ONU transmission. Upon receiving the transmission, the OLT calculates the distance to the ONU and sends a Ranging_Time PLOAM message to indicate to the ONU the new Equalization Delay to use in future transmissions. ONU State S1 State S2 State S3 OLT State S4 Activation process
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- 84. 84 PCBd Payload NPCBd Payload N+1 PCBd Payload N+2 Start of DS Frame From OLT Point of View Quite window 250 useg Earliest Expected Response PLOAM Latest Expected Response PLOAM Propagation Delay 0-100us ONU response Time 34-36us Pre- Asigned delay Random Delay 0-48us PCBu Start Time PLOAMu Stop Time Propagation Delay Timing relationships during serial number acquisition SN Request Alloc ID 254 Start Time X Stop time X+12
- 85. 85 DS- PayloadPCBd BwMappSync US- PayloadPCBu Startof DS Frame From OLT Point of View Propagation Delay Onu Response Time Requested Delay StartTime StopTime Start of DS Frame From ONU Point of View Propagation Delay US Burst Start of US Frame From ONU Point of View OLT ONU ONU response time is a system-wide parameter that is chosen to givet he ONU sufficient time to receive the downstream frame, including Upstream bandwidth map, perform DS and US FEC as needed, and prepare an upstream response. The value of the ONU response time is 35±1 μs. Requisite delay refers to the total extra delay that an ONU may be required to apply. The purpose of the requisite delay is to compensate for variation of propagation and processing delays of individual ONUs, and to avoid or reduce the probability of collisions between upstream transmissions. Typical timing for ONU upstream transmissions
- 86. 86 OMCI (ONT Management andControl Interface) ME´s (Management entities)
- 87. 87 • A wayof MIB (Management Information Base) formed by Management Entities (ME´s) is used to fully describe the ONU configuration, status and several other actions • OMCI constitute the protocol in order to support the set of actions performed over ONU to create; delete and other set of actions on those ME´s OMCI
- 88. 88 OMCI Introduction • OMCI(ONT Management and Control Interface) is an OAM service that provides a standard way to discover ONU capabilities and to manage and control them • OMCI protocol runs across an GEM connection (OMCC) between OLT and ONU • OMCI is asymmetric: OLT is the master and ONU is the slave • A single OLT may use multiple OMCI instances over multiple OMCI channels to control multiple ONUs • It allows OLT to perform following functions: – Manage UNI at the ONU. Establish and release connections across the ONU. – Request configuration information and performance statistics. – Autonomously inform system operator of events/alarms (AVC, link failures). • Standards – G.984.4 (2008/02) – G.984.4 (2009 AMD1 and AMD2) – G.988 OMCI
- 89. 89 OMCI Protocol define: •OMCI Message Format • OMCI Operation Procedure • Protocol-independent OMCI MIB Description – Defined in terms of managed entities (MEs). – MEs are abstract representations of resources and services in an ONU. – ME´s Covered Function Areas : • Configuration Management • Fault Management • Performance Management • Security Management OMCI
- 90. 90 OMCI Message Format GEM Header (5Bytes) Transaction Correlation Identifier (2 Bytes) Message Type (1 Byte) Device Identifier (1 Byte) Message Identifier (4 Bytes) Message Contents (32 Bytes) OMCI Trailer (8 Bytes) 53 Byte GEM Cell PortID (12bits) for the OMCC for the addressed ONU - MSB=1 (high priority) - MSB=0 (low priority) - OLT defines this identifier to correlate REQ and RSP - 0x0000 for notification messages. 0x0A for GPON ME Identifier (ME Class Value) ME Instance DB AR AK MT 32 17 16 1 Message Type AK=1, Msg is an ACK AR=1, ACK requested0 Max # of MEs is 65535 Max # of Instances per ME is 65536 0x0 L CRC Length = 0x28 ITU-T I.363.5 OMCI
- 91. 91 OMCI Message Types •Common Operations – Create, Delete, Set, Get – Get Next: for table attributes. – Performance Monitoring: Get Current Data • MIB Upload & Reset – MIB Upload, MIB Upload Next, MIB Reset • Alarm Retrieval – Get All Alarms, Get All Alarms Next • Software Download – Start Download, Download Section, End Download, Activate Software, Commit Software • Others – Test, Reboot, Synchronize Time OMCI
- 92. 92 OMCI ME Definition •A Managed Entity (ME) is composed of attributes, actions and notifications defining its characteristics. • Managed Entity (ME Class Value) – Purpose of the entity – Autonomously instantiated by ONU or explicitly created by OLT – Relationship(s) with other managed entities • Attributes: Attribute Definition – ME id: This attribute provides a unique number for each instance of this managed entity. – List of attributes. Attribute Number within ME Determined by the Order in Which Attributes are Listed • Actions: operations that may be performed on the entity (Create/Get/Set/Test, etc.) • Notifications (Alarm, AVC, TCA, Test Result) • There can be multiple instances of a Managed Entity. Each instance has the same attributes, actions and notifications even though the values of the attributes may be different from each other. OMCI
- 93. 93 Managed entities: • Theprotocol-independent MIB has been defined in terms of managed entities (ME´s) • The managed entities are abstract representations of resources and services in an ONT. Managed entity A Entity created by ONU Managed entity B Entity created by OLT Managed entity A Managed entity B Entity A has explicit pointer to entity B Managed entity B Managed entity A Entity A has implicit ID relationship to entity B (ME IDs are equal) Managed entity A Managed entity B There can be 0..X instances of A related to B 0..X 1 Managed entity A Managed entity B1 1 There is a 1 to 1 relationship of A to B OMCI
- 94. 94 MAC bridge service profile MAC bridge portconfig data MAC bridge port config data 0..m 0..p GEM interwork- -ing TP PPTP xx UNI 1 0..1 UNI GEM port network CTP 1 0..1 0..1 MAC bridge port filter table 1 1 0..w 1 1 0..1 1 VLAN tagging filter data 1 1 OMCI
- 95. 95 MAC bridge service profile Managed entityid: Spanning tree ind Learning ind: Port bridging ind: Priority Max age: HELLO time: Forward delay MAC learning depth: Unknown MAC address discard: MAC bridge port config data Managed entity id: Bridge id pointer: Port num: TP type: Physical path termination point Ethernet UNI IEEE 802.1p mapper service profile IP host config data GEM interworking termination point Multicast GEM interworking termination point TP pointer: Port priority: Port path cost: Port spanning tree ind: Port MAC address: OMCI
- 96. 96 GEM interwork- -ing TP Managed entityid: GEM port network CTP connectivity pointer: Interworking option: 0 Circuit-emulated TDM 1 MAC bridged LAN 2 Reserved 3 Reserved 4 Video return path 5 IEEE 802.1p mapper 6 Downstream broadcast 7 MPLS PW TDM service Service profile pointer: Interworking termination point pointer: CES service profile if interworking option = 0 MAC bridge service profile if interworking option = 1 Video return path service profile if interworking option = 4 IEEE 802.1p mapper service profile if interworking option = 5 Null pointer if interworking option = 6 CES service profile if interworking option = 7 OMCI
- 97. 97 Layer 2 functions OMCIsupports two major layer 2 traffic mapping models: • MAC bridging: described in [IEEE 802.1D] and [IEEE 802.1Q] • "IEEE 802.1p mapping". OMCI
- 98.
- 99. 99 IEEE 802.1p mapping IEEE802.1p mapper service profile A managed entity witch associates the priorities of IEEE 802.1p [IEEE 802.1D] priority tagged frames with specific connections. This managed entity directs upstream traffic to the designated GEM ports. OMCI
- 100. 100 The two basiclayer 2 services can be used in various combinations to achieve different overall connectivity's. • N:1 bridging, where a bridge is used to serve multiple UNI ports from a single ANI service. • 1:M mapping, where a mapper is used to serve a single UNI with multiple ANI connections, based on IEEE 802.1p priorities. • 1:P filtering, where a bridge with filters is used to serve a single UNI with multiple ANI connections, based on some VLAN information other than IEEE 802.1p priorities. More “Exotic” combination can be realized OMCI
- 101. 101 N : 1MAC Bridging N IEEE BRIDGE OMCI
- 102. 102 802.1p Bit´s GEM´s X 1:P Mapping OMCI
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- 108. 108 DBA • What isDBA? • DBA, Dynamic Bandwidth Assignment • Why DBA? • It enhances the uplink bandwidth utilization of PONports. • More users can be added on a PON port. • Users can enjoy higher-bandwidth services, especially those requiring comparatively greater change in terms of the bandwidth. • DBA operation modes: • SR-DBA: status report-DBA • NSR-DBA: non status report-DB Dynamic Bandwith Allocation
- 109. 109 Dynamic Bandwidth Assignment(DBA): Aprocess by which the optical line terminal (OLT) distributes the upstream PON capacity between the traffic-bearing entities within optical network units (ONUs), based on the dynamic indication of their activity statusa nd their configured traffic contract Status Reporting DBA (SR-DBA): A method of dynamic bandwidth assignment that infers the dynamic activity status of the traffic-bearing entities within optical network units (ONUs) based on the explicit buffer occupancy reports communicated over the embedded OAM channel. Traffic-Monitoring DBA (TM-DBA): A method of dynamic bandwidth assignment that infers the dynamic activity status of the traffic-bearing entities within optical network units (ONUs) based on the observation of the idle GEM frame transmissions in place of granted upstream bandwidth allocations. Dynamic Bandwith Allocation
- 110. 110 SR-DBA Operation Dynamic BandwithAllocation
- 111. 111 SR-DBA Operation Payload DynamicBandwith Allocation
- 112. 112 Static Bandwith Allocation DynamicBandwith Allocation Dynamic Bandwith Allocation
- 113. 113 NSR-DBA Operation NSR isan algorithm scheme that realizes DBA. It helps to predict the bandwidth allocated to each ONU based on the traffic from ONUs. Procedure: Step1: Monitor the number of data packets received by OLT within the specified interval. Step2: Use the result of real time monitoring in step 1 to calculate the utilization rate. Step3: Recognize the congestion status by comparing the utilization rate with the specified limits. Dynamic Bandwith Allocation
- 114. 114 GPON MULTICASTING FOR IPTVSERVICES
- 115. 115 Video Over GPON: •Two ways Video Overlay (VFO) IP Video
- 116. 116 Upper Layers TDMPOTS DATA Layer 4 Layer 3 Layer 2 Physical TCP/UDP IP Ethernet GEM (Generic Encapsulation Method) GTC-TC Frame (GPON Transmission Convergence frames ) PON PHY VIDEO VideoOverlay Video Over GPON
- 117. 117 Elements Video Overlay 1:2 Spliter Spliter OLT ONUONU ONU Video RF1550nm ONU´s Are equiped with triplexers components Optical Mux RF RF RF
- 118. 118 Switch Forward IGMP Control Switch Forward IGMP Control U Interface V Interface ONU RG OLT GPONhas native Multicas characteristics Becasue its P2Mp Nature well suited for IPTV distribution Down Stream Multicas Flow Up Stream Control Flow Video Over GPON
- 119. 119 Switch Forward IGMP Control Switch Forward IGMP Control U Interface V Interface ONU RG OLT JoinMsg or Leave Msg Mcast Flow Video Over GPON
- 120. 120 GPON Side Ethernet Side Joint,Leave Mesages Multicast Flows Joint, Leave Mesages Multicast Flows Same VLAN ID For US and DS Diferent GEM Ports ID Video Over GPON
- 121. 121 Multicasting on aL2 Network (The Elements) IGMP aware Core L2 network L2 GPON IGMP aware Acces Network Head End ONU ONU ONU StO StO StO OLT L2 Switches IP-TV Down converter Video Over GPON
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- 123. 123 PON Standards Full ServiceAccess Network (FSAN) Group Ethernet in the First Mile (EFM) Alliance International Telecommunication Union (ITU-T) Institute of Electrical & Electronics Engineers (IEEE) APON/BPON (G.983) EPON (802.3ah)GPON (G.984) Propose standards Ratify standards Working Groups Standards Bodies Standards 10G-PON (802.3av) NG-PON (G.987) GPON STANDARDS
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- 126. 126 OLT/SW T T T T T10GigE 1GigE ONU ONU ONU GPON plus P2PSERVICESS Access Access Access Service Modeling
- 127. 127 TCONT GEM PORT CE-VLAN CE-VLAN CE-VLAN Trunkport Service Ethernet Up Stream anddown stream point of View CE-VLAN CE-VLAN CE-VLAN GEM Port UpDown Service Modeling TCONT GEM PORT Ethernet Flow Ethernet Flow Ethernet Flow Accessport Service Ethernet CE-VLAN GEM Port UpDown VLAN
- 128. 128 OLT/SW T T T T T10GigE 1GigE ONU ONU ONU CMSW GPON plus P2PSERVICESS VLAN 10 VLAN 11 VLAN 12 VLAN 11 VLAN 12 VLAN 13 VLAN 14 VLAN 12 VLAN 13 Service Modeling
- 129. 129 TCONT GEM PORT CE-VLAN CE-VLAN CE-VLAN Trunkport TCONT GEM PORT CE-VLAN CE-VLAN CE-VLAN TCONT GEM PORT CE-VLAN CE-VLAN CE-VLAN Trunkport Service Ethernet Service Ethernet Service Ethernet Up Stream anddown stream point of View CE-VLAN CE-VLAN CE-VLAN GEM Port CE-VLAN CE-VLAN CE-VLAN GEM PORT CE-VLAN CE-VLAN CE-VLAN GEM PORT UpDown Service Modeling
- 130. 130 TCONT GEM PORT Trunkport Q in QService Ethernet GEM Port UpDown Q in Q CE-VLAN CE-VLAN CE-VLAN SP-VLANSP-VLAN TCONT GEM PORT Trunkport Q in Q Service Ethernet GEM Port UpDown Q in Q CE-VLAN CE-VLAN SP-VLAN #1 Q in Q CE-VLAN CE-VLAN SP-VLAN #2 SP-VLAN #1 SP-VLAN #2 Service Modeling
- 131. 131 TCONT GEM PORT Trunk port Qin Q Service Ethernet GEM Port UpDown Q in Q CE-VLAN CE-VLAN SP-VLAN #1 Q in Q CE-VLAN CE-VLAN SP-VLAN #1 SP-VLAN #2 TCONT GEM PORT SP-VLAN #2GEM PORT Service Modeling
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- 134. 134 LD2502 - 16E1 LD2502– 4STM-1 LD2502 LD2504 LD2504 – 4STM-1 LD2504 - 16E1
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- 136. 136 • Main characteristics –Ports • RS323 for Local Console. • 2 GigE ports • 1 GPON port – Power Supply • External. Optional Battery backup. – Software (Main Features) • Bridged Unit. • G984.2; G984.3; G984.4 Fully compatible. • 802.1Q/P support. • 4 queues per GigE ports. • IP for management in band (IP-Host ME) NOTE: The graph shows only a generic prototype
- 137. 137 • Hardware: – ThisONU will be deployed with 3 party Hardware and Software developers. • FITEC. – Ports • RS232 Console Port • 3 Fast Ethernet Port • 1 GigE Port • 2 E1 G703 (75/120ohms) ports. • 1 External alarm connector • External E1 clock – Power Supply • Internal Full range w/ Redundancy • Software Main Characteristics. – Bridged ONU. – IEEE 802.1Q/P. – G984.4; G984.3 fully compliant . – E1 Emulation Services based on SAToP Standards and MEF Encapsulation Method.
- 138. 138 OLT 2500 GPON ODN E1 E1 E1 EthONU 1600 ONU500 ONU500 ONU500-S ONU500-S CMSW CMSW ONU1600 PSTN 10GigE xSTP EAPs Routing GW GW 10GigE Internet GigE Serv. GigE Serv.
- 139. 139 OLT Split ONU 1 ONU 2 ONU 3 10Gig 1GigE 100M 100M 100M R1 SW1 R2 SW2 100M 100M 100M T T T TrunkPorts Access Port With PVID User defined T T •LAN Servicess •All Services will be provided “trough VLANs”. • Ports will be acting as Trunk ports or Access (PVID) ports. • ONUs will acts as “protocol adapters” between Eth and GPON. •no protocols others than those related with GPON will be provided
- 140. 140 VLAN Mapper GEM Mapper TCON Mapper TCON Mapper TCON Mapper GEM Mapper VLAN Mapper P2 P1 Distintas puertas Mismas VLANs(PVID) Mismo GEM Mismo TCON P3 Distinta VLAN (PVID) Distinto GEM Distinto TCON GEM Mapper VLAN Mapper P4 N VLANs Un GEM Un TCON GPON Access Ports With PVID Trunk Ports With N VLANs “In some sense the ONU will act like a remote SW.” LAN Services
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- 142. 142 VLAN Mapper GEM Mapper TCON Mapper GEM Mapper VLAN Mapper GEM Mapper VLAN Mapper GPON TCON Mapper E1-1 E1-2 E1-3 E1 Services willbe mapped as LAN Services: On a VLAN GEM T-CONT
- 143. 143 LightDrive5(config)#sh run ! no servicepassword-encryption service ssh enable service telnet enable ! hostname LightDrive5 ! log stdout username asga privilege 15 password asga ! ip domain-lookup ! load-interval 15 bridge protocol stp bridge acquire ! spanning-tree mst config ! interface gpon0.1 switchport switchport mode trunk ! interface gpon0.2 switchport switchport mode trunk ! ! interface xe0.1 switchport switchport mode trunk ! NEW Interfaces / Context Added from GPON “modules” Existing Interfaces / Context from BCM New interfaces on top menu: GPONY.X Interface. Heritages many GigE or Xe attributes.
- 144. 144 LightDrive5(config)#link-profile PEPE LightDrive5(config-gpon-link)#? commands: delimiter Delimiterparameters ds-fec-mode Downstream FEC mode (Default: disable) exit End current mode and down to previous mode help Description of the interactive help system idle idle parameters max Configuration max values of some link variables preassigned-eqd Pre-assigned equalization delay (Default: 0 usec) rx Link receive parameters show Show running system information LightDrive5(config-gpon-link)# The “Link profile” top menu. Configuration Context. Profiles.
- 145. 145 LightDrive5(config)#link-profile PEPE2 LightDrive5(config-gpon-link)#? commands: delimiter Delimiterparameters ds-fec-mode Downstream FEC mode (Default: disable) exit End current mode and down to previous mode help Description of the interactive help system idle idle parameters max Configuration max values of some link variables preassigned-eqd Pre-assigned equalization delay (Default: 0 usec) rx Link receive parameters show Show running system information LightDrive5(config-gpon-link)#rx ? alpha Delimites number of errors before send the signal bcdr Burst CDR parameters delimiter Delimiter parameters ed Energy Detection la LA parameters ranging-size Ranging access window size (0-127) (Default: 0). wait-size Wait window size (0-127) (Default: 0). LightDrive5(config-gpon-link)#rx ed ? inversion When set to True, ED pin will be inverted in the Rx block (Default: true) pattern Pattern (0x00 - 0xFF) (Default: 0xAA) size Pattern Size (0-2) (Default: 0) windows-size Number of cycles to wait for energy detection (0-128) (Default: 128) LightDrive5(config-gpon-link)#rx ed inversion ? false False true True LightDrive5(config-gpon-link)#rx ed inversion false LightDrive5(config-gpon-link)# Top “link-profile menu” Second level from “link-profile menu” The Rx sub menu Third level from “link-profile menu” The “ed” sub menu Setting the “ed” variable. To “false” Sailing on sub menus (tree of commands) or context. Same idea, AsGOS.
- 146. 146 LightDrive5> LightDrive5>en LightDrive5#sh run ! no servicepassword-encryption service ssh enable service telnet enable ! hostname LightDrive5 ! log stdout username asga privilege 15 password asga ! ip domain-lookup ! load-interval 15 bridge protocol stp bridge acquire ! spanning-tree mst config ! link-profile PEPE2 rx ed inversion false ! interface gpon0.1 switchport switchport mode trunk ! interface gpon0.2 associate link-profile PEPE2 switchport switchport mode trunk ! LightDrive5(config-if)#associate link-profile PEPE2 % Warning. If link is enable, It's necessary to reinitialize the OLT to the link profile take effect LightDrive5(config-if)# Link profile Association The Link profile definitions. The Associated Link profile command
- 147. 147 LightDrive5(config)protocol-profile <teste> alloc-size 100 berus-interval 300 ber ds-interval 300 ber sf-threshold 7 ber sd-threshold 7 dba-size 1001 disable-onu disable deactivate-onu disable drift interval 1001 drift limit 5 los-gpio-pin 10 los-initial enable guard-bits 1001 key-encrypted enable min round-trip 100 min onu-response 100 mcast-encryp disable preamble tx 0x1 0x2 0x3 0x4 preamble type 0x1 pwd-request disable us-fec enable tx-ctl-limit 100 ! Protocol Profile Protocol profile Top Menu Variables. Then this profile must be associated to a particular GPON Port. No association means Default values will Be used
- 148. 148 • Service Provisioning(The Elements) – ONU-PROFILE: a “Class” that contain al sub elements/clases Needed to fully specify a set of services. Profiles will be applied to a specific ONU. – Service-ethernet: a sub “class” inside of a profile that fully specify of a particular service (Data; VOIP or E1) ! onu-profile <onu profile name> service ethernet <service ID> interface-eth 1 associate service ethernet <service id> ! Specific “objects/variables” that fully configure that service Service Association to a specific Physical port
- 149. 149 • Access portversus trunk ports – Same concepts than LightBolt Switches. ! onu-profile dhcp service ethernet 1 switchport mode access switchport access vlan 111 service ethernet 2 switchport mode trunk switchport trunk allowed vlan add 101-103 interface-eth 1 associate service ethernet 1 interface-eth 2 associate service ethernet 2 ! Service Ethernet for an Access port Service Ethernet for a Trunk port Service Ethernet applied to specific Physical ports
- 150. 150 onu-profile dhcp service ethernet1 tcont 1 cir 1024 pir 1024 traffic-shapping cir 3968 pir 4480 switchport mode access switchport access vlan 111 service ethernet 2 tcont 1 cir 1024 pir 1024 traffic-shapping cir 1024 pir 1024 switchport mode trunk switchport trunk allowed vlan add 101-103 interface-eth 1 associate service ethernet 1 interface-eth 2 associate service ethernet 2 Define the CIR and PIR for up stream flow Define the CIR and PIR for down stream flow Define the CIR and PIR for up stream flow Define the CIR and PIR for down stream flow All VLANs on the Same TCON And GEM port will be “shaped” • T-CONTs and GEM ports traffic shaping configuration.
- 151. 151 TCONT GEM PORT CE-VLAN CE-VLAN CE-VLAN Trunkport Service Ethernet CE-VLAN CE-VLAN CE-VLAN GEM Port UpDown service ethernet 2 tcont1 cir 1024 pir 1024 traffic-shapping cir 1024 pir 1024 switchport mode trunk switchport trunk allowed vlan add 101-103 interface-eth 2 associate service ethernet 2
- 152. 152 • T-CONTs andGEM ports traffic shaping configuration. onu-profile dhcp service ethernet 1 tcont 1 cir 1024 pir 1024 traffic-shapping cir 3968 pir 4480 switchport mode access switchport access vlan 111 service ethernet 2 tcont 3 cir 1024 pir 1024 traffic-shapping cir 1024 pir 1024 switchport mode trunk switchport trunk allowed vlan add 101-103 service ethernet 3 tcont 2 cir 1024 pir 1984 traffic-shapping cir 1024 pir 1984 switchport mode trunk switchport trunk allowed vlan add 104-108 interface-eth 1 associate service ethernet 1 interface-eth 2 associate service ethernet 2 associate service ethernet 3 “N” VLANs mapped to a TCON and a GEM port. Shaped and policed to a Specific BW value “M” VLANs mapped to a TCON and a GEM port. Shaped and policed to a specific BW value Service 2 and 3 applied to the same physical interface
- 153. 153 Trunkport TCONT GEM PORT CE-VLAN CE-VLAN CE-VLAN TCONT GEM PORT CE-VLAN CE-VLAN CE-VLAN Service Ethernet Service Ethernet CE-VLAN CE-VLAN CE-VLAN GEM PORT CE-VLAN CE-VLAN CE-VLAN GEM PORT UpDown service ethernet 2 tcont3 cir 1024 pir 1024 traffic-shapping cir 1024 pir 1024 switchport mode trunk switchport trunk allowed vlan add 101-103 service ethernet 3 tcont 2 cir 1024 pir 1984 traffic-shapping cir 1024 pir 1984 switchport mode trunk switchport trunk allowed vlan add 104-108 interface-eth 2 associate service ethernet 2 associate service ethernet 3
- 154. 154 • IP-Host asservice management interface onu-profile dhcp service ethernet 1 tcont 1 cir 1024 pir 1024 traffic-shapping cir 3968 pir 4480 switchport mode access switchport access vlan 111 service ethernet 2 tcont 3 cir 1024 pir 1024 traffic-shapping cir 1024 pir 1024 switchport mode trunk switchport trunk allowed vlan add 101-103 service ip-host vlan 55 ip address dynamic interface-eth 1 associate service ethernet 1 interface-eth 2 associate service ethernet 2 Configure the IP-Host service used for management on a specific VLAN ID. In this example It use a dynamic DHCP client to take its IP parameters.
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Editor's Notes
- #48 La funcion de esta capa es la de multiplexar los flujos de control y de datos se puede observar uno orientado a lo fisico tal y como su nombre lo indica PLOAM y outro um tanto mas logico OMCI Lod flujo s de control PLOAM se aplican directamente sobre las tramas ya formadas de GEM Los Flujos de OMCI hay que asignarles um GEM Ambos son “enmarcados “ el el flujo de GEM
- #54 8.1.3.6.2 Flags field The flags field is a 12-bit field that contains 4 separate indications on how the allocation shall be used. The meaning of these indications is as follows: – Bit 11 (MSB): Send PLSu (power levelling sequence): If this bit is set, the ONU shall send its PLSu information during this allocation. If this bit is not set, the ONU will not send the PLSu information in this allocation. – Bit 10: Send PLOAMu: If this bit is set, the ONU shall send its PLOAMu information during this allocation. If this bit is not set, the ONU will not send the PLOAMu information in this allocation. – Bit 9: Use FEC: If this bit is set, the ONU shall compute and insert FEC parity during this allocation. Note that this bit should be the same for the life of the allocation ID, and is merely an in-band confirmation of previously known data. – Bits 8 and 7: Send DBRu (mode): Depending on the contents of these two bits, the ONU will send the DBRu corresponding to the allocation ID or not. The code points defined are: 00: Do not send DBRu at all. 01: Send the 'mode 0' DBRu (two bytes). 10: Send the 'mode 1' DBRu (three bytes). 11: Send the 'mode 2' DBRu (five bytes). The description of the syntax of the different DBRus is given in 8.4. Note that the ONU must respond with the required number of bytes, regardless of what mode it actually supports. Bits 6-0: Reserved for future use.
- #62 1) physical layer overhead (PLOu); PCBu 2) physical layer operations, administration and management upstream (PLOAMu); 3) power levelling sequence upstream (PLSu); 4) dynamic Bandwidth Report upstream (DBRu).
- #63 1
- #67 BCH :: Bose, Chaudhuri, and Hocquenghem