| Acronym | Description | Application | Group | Read more |
|---|---|---|---|---|
| ACR | Adaptive Clock Recovery | A method for TDM pseudowires that ensures the TDM signals are clocked at the same rate at the near- and the far-end of a TDM over Packet connection. The adaptive method does not require support of Synchonous Ethernet or PTP protocols. See also DCR | tdmop | TDM over Packet Solutions |
| ADM | Add-Drop Multiplexer | A type of SONET/SDH network element providing transport of Ethernet, IP, MPLS, and TDM services | Equipment | |
| AIS | Alarm Indication Signal | Indication that a fault is detected in the originating or upstream equipment | Alarm | |
| APS | Automatic Protection Switching | Using 2 fiber pairs between SONET/SDH nodes to increase the availibility of the connection, through protection against fiber, node or operator failures | Protocol | |
| B1, B2, B3 | BIP level 1, 2, 3 | A SONET/SDH overhead byte for link monitoring based on parity generation and check. Also B2 and B3 are defined, monitoring at sub-channel levels. | Overheadbyte | |
| BERT | Bit Error Rate Test | A method to test network connections. A generator creates a specific test pattern, e.g. PRBS, which is sent across a TDM network path. At the far end, or along the path, a monitor verifies whether the received stream matches the pattern, and reports any received bit errors. | Test | |
| BITS | Building Integrated Timing System | Equipment that generates and distributes high-quality synchronization signals inside a telecom building, often based on high stability oscillators and using GPS as a reference signal | synchronization | Synchronization |
| BLSR | Bidirectional Line Switched Ring | Using 2 fiber pairs between all SONET nodes in a ring topology to increase the availibility of connections, through protection against fiber, ring network, node or operator failures. SONET terminology for MS SPRING. | Protocol | |
| CEM | Circuit EMulation | Generic term for Circuit Emulation Service, related terminology are TDM over Packet and Pseudo Wire | tdmop | TDM over Packet Solutions |
| CEP | (SONET/SDH) Circuit Emulation over Packet | A method to transport SONET SPEs or SDH Virtual Triburaries over a packet network using pseudowire concepts (IETF RFC 4842) | tdmop | TDM over Packet Solutions |
| CES | Circuit Emulation Service | A method to transport a TDM circuit (e.g. E1, T1, SONET, SDH, CPRI) over a packet network. This is a special case of pseudowire transport | tdmop | TDM over Packet Solutions |
| CESoPSN | Circuit Emulation Service over Packet Switched Network | A method to transport PDH TDM services structure aware over a packet network using pseudowire concepts (IETF RFC 5086) | tdmop | TDM over Packet Solutions |
| CPoP SFP | Channelized PDH over Packet | A Smart SFP with DS3 line interface, with a M13 multiplexer supporting packet transport for up to 28 DS1 channels via SAToP | smartsfp | Smart SFP |
| CPRI | Common Public Radio Interface | A standarized method to transport mobile network radio data across a electrical or optical link | Protocol | |
| CSoP SFP | Channelized SONET/SDH over Packet | A Smart SFP with OC3/STM1 line interface, with an embedded multiplexer supporting packet transport for up to 84 DS1 or 63 E1 channels via SAToP | smartsfp | Smart SFP |
| CV | Code Violation | Indication that a CRC or parity error is present in received data | Alarm | |
| DACS | Digital Access and Cross-connect System | A type of network element providing cross connections of 100s or 1000s of SONET/SDH, PDH or TDM services | Equipment | |
| DCC | Data Communications Channel | A low speed in-band channel for engineering or operations support between SONET/SDH or OTN network elements, also know as ECC or GCC | channel | Smart SFP |
| DCR | Differential Clock Recovery | A method for TDM pseudowires that ensures the TDM signals are clocked at the same rate at the near- and the far-end of a TDM over Packet connection. The differential method relies on a network wide reference clock using Synchonous Ethernet or PTP protocol. See also ACR. | tdmop | TDM over Packet Solutions |
| DCS | Digital Cross-connect System | A type of network element providing cross connections of 100s or 1000s of SONET/SDH, PDH or TDM services | Equipment | |
| DS0 | Digital Signal Level 0 | 64 Kb/s data/voice channel | Channel | |
| DS1 | Digital Signal Level 1 | A TDM signal operating at 1 544 kb/s. The signal can be transported over a T1 line, or multiplexed via DS3, SONET or SDH | Channel | |
| DS3 | Digital Signal Level 3 | A TDM signal operating at 44 736 kb/s. The signal can be transported over a T3 line, or multiplexed via SONET or SDH | channel | Smart SFP |
| E1 | E signal level 1 | A TDM signal operating at 2 048 kb/s. The signal can be multiplexed via SONET or SDH | Channel | |
| E3 | E signal level 3 | A TDM signal operating at 34 368 kb/s. The signal can be multiplexed via SONET or SDH | channel | TDM over Packet Solutions |
| ECC | Embedded Communications Channel | A low speed in-band channel for engineering or operations support between SONET/SDH or OTN network elements, also know as DCC or GCC | Channel | |
| ECID | Ethernet Circuit IDentifier | A header field that uniquely identifies a TDM pseudowire channel on an Ethernet network (MEF-8) | tdmop | TDM over Packet Solutions Smart SFP |
| EEC | Ethernet Equipment Clock | The clock function inside Ethernet equipment that generates and distributes high-quality synchronization signals on the Ethernet network | synchronization | Synchronization |
| EMS | Element Management System | A management system that typically supports a single or few equipment nodes | Management | |
| EOC | Embedded Operations Channel | A low speed in-band channel for engineering or operations support between SONET/SDH or OTN network elements | Channel | |
| EOS | Ethernet over SONET/SDH | Ethernet packet transport via GFP over SONET/SDH network | protocol | EoS Smart SFP |
| EoS SFP | Ethernet over SONET/SDH | A Smart SFP supporting point to point Ethernet transport across a SONET/SDH network via the optical OC48/STM16 interface | Smart SFP | Smart SFP |
| EOW | Engineering Order Wire | A low speed in-band channel for engineering or operations support between SONET/SDH or OTN network elements | Channel | |
| EPAR | Explicit Pointer Adjustment Request | A method to transparently forward pointer adjustments from SONET/SDH layer across a CEP pseudowire. Related methods are ACR and DCR. | tdmop | TDM over Packet Solutions Smart SFP |
| ETH | Ethernet | A networking technology based on packet forwarding, using the Destination MAC address to determine the next destination | Network | |
| GCC | General Communications Channel | A low speed in-band channel for engineering or operations support between OTN network elements | Channel | |
| GFP | Generic Framing Procedure | A generic method to encapsulate client service signals such as Ethernet, IP or MPLS packets for transport over SONET/SDH or OTN networks | protocol | EoS Smart SFP |
| HDLC | High-level Data Link Control | A bit-oriented transparent synchronous data link layer protocol (ISO/IEC 13239:2002) | Protocol | |
| IP | Internet Protocol | A networking technology based on packet forwarding, using the IP address to determine the next destination | Network | |
| IWF | Interworking Function | The function that converts serial TDM data into packets and vice versa, in TDMoP equipment | equipment | TDM over Packet Solutions Smart SFP |
| J0, J1, J2 | J byte overhead | A SONET/SDH overhead byte used for link or path identification purposes. | Overheadbyte | |
| K1, K2 | K byte overhead | A pair of SONET/SDH overhead bytes used for link status reporting and transfer of protection protocol information between SONET/SDH nodes. See also APS. | Overheadbyte | |
| LAPD | Link Access Procedure-D Channel | A data link layer protocol used for OAMP transport across SONET/SDH or OTN networks | Protocol | |
| LBO | Line Build Out | A function in a LIU device to prevent cross-talk on short electrical TDM links using a configurable level of output signal attenuation | Equipment | |
| LCAS | Link Capacity Adjustment Scheme | A method to automatically adjust the bandwidth of a VCG based on availability of end-to-end Virtual Connections | Protocol | |
| LIU | Line Interface Unit | The physical layer interface chip, supporting TDM signals such as E1, T1 or T3 | equipment | Transparent Network Migration |
| LOC | Loss of Clock | Indication that the Clock signal of the received signal is lost or not usable | Alarm | |
| LOF | Loss of Frame | Indication that the frame structure of the received signal is lost | Alarm | |
| LOP | Loss of Pointer | Indication that the Pointer value can not be detected in the received signal, in SONET/SDH equipment | Alarm | |
| LOPS | Loss of Packet Synchronization | Indication that some or all received packets are lost, in TDMoP equipment | Alarm | |
| LOS | Loss of Signal | An alarm that indicates no signal is received | Alarm | |
| LPL | Local Packet Lost | Indication that a single packet is lost, due to missing sequence number, in TDMoP equipment | Alarm | |
| M13 | MUX DS1 DS3 | A function to aggregate multiple DS1 signals for transport over a DS3 link | equipment | Channelized Network Migration |
| MEF | Metro Ethernet Forum | An organization defining standards for Ethernet networks and services. | Organization | |
| MLPPP | Multi-Link Point-to-Point Protocol | A method to increase network bandwidth using a bundle of PPP links | Protocol | |
| MPLS | Multi Protocol Label Switching | A networking technology based on packet forwarding, using a label to dermine the next destination | Protocol | |
| MSP | Multiplex Section Protection | Using 2 fiber pairs between SONET/SDH nodes to increase the availibility of the connection, through protection against fiber, node or operator failures | Protection | |
| MSPP | Multiservice Provisioning Platform | A type of SONET/SDH network element providing transport of Ethernet, IP, MPLS, and TDM services | Equipment | |
| MS SPRING | Multiplex Section Shared Protection Ring | Using 2 fiber pairs between all SONET/SDH nodes in a ring topology to increase the availibility of connections, through protection against fiber, ring network, node or operator failures. SONET terminology for BLSR. | Protection | |
| MTIE | Maximum Time Interval Error | A method to measure the quality of a TDM signal using the maximum time error with respect to a stable reference over a given time interval | synchronization | Synchronization |
| MUX | Multiplexer | A network element in a PDH, SONET/SDH or OTN network that aggregates TDM signals for transport | equipment | Channelized Network Migration |
| NIM | Non-Intrusive Monitor | A function on PDH or SONET/SDH equipment to monitor quality or status of TDM traffic while it passes through the equipment. It is non-intrusive in the sense that it does not change the content of the signal, it only reports observed bit-errors as failures or as a performance count | Equipment | |
| NMS | Network Management System | A management system that supports a network level view of large set of equipment nodes | Management | |
| NTP | Network Time Protocol | A method to distribute time across an IP packet network (IETF RFC 5905) | synchronization | Synchronization |
| NUT | Non-preemptive Unprotected Traffic | A specific use-case defined in the BLSR or MS SPRING protection protocol, allowing higher usage of available path resources on a TDM ring network. | Protection | |
| OAM | Operations, Administration and Maintenance | A set of management functons supported on a network interface or equipment nodes | Management | |
| OAMP | Operations, Administration, Maintenance and Provisioning | A set of management functons supported on a network interface or equipment nodes | Management | |
| OC-3 | Optical Carrier level 3 | A SONET fiber connection operating at 155.52 Mb/s | channel | Smart SFP |
| OC-n | Optical Carrier-number | A SONET fiber connection operating at n * 51.84 Mb/s. OC-1, OC-3, OC-12, OC-48, OC-192 and OC-768 are defined. | channel | Smart SFP |
| OSPF | Open Shortest Path First | A routing protocol for packet networks using a shortest path algorithm to determine optimal routes | Protocol | |
| OTN | Optical Transport Network | A networking technology using pre-allocated fixed capacity paths for end-to-end traffic connections | Network | |
| OTU | Optical Transport Unit | A channel supported in OTN network hierarchy | Channel | |
| OW | Order Wire | A low speed in-band channel for operations support between SONET/SDH or OTN network elements | Channel | |
| PDH | Pleisiochronous Digital Hierarchy | A networking technology using pre-allocated fixed capacity paths for end-to-end traffic connections; a multiplexing structure with near synchronous timing is used to combine multiple paths on a single link | Network | |
| PJ | Pointer Justification | Indication that a positive or negative pointer adjustment was detected in the received signal, in SONET/SDH equipment | Alarm | |
| PLE | Private Line Emulation over Packet | A method for encapsulating high-speed serial signals over packet switched networks. This emulation suits applications where complete signal transparency is required (IETF draft schmutzer bess ple) | tdmop | TDM over Packet Solutions |
| PLM | Payload Label Mismatch | Indication that the payload received in the relevant channel does not match with the expected payload type, in SONET/SDH equipment | Alarm | |
| POH | Path Overhead | An overhead channel at the path layer in SONET/SDH | channel | Smart SFP |
| POS | PPP over SONET/SDH | A method for transporting multi-protocol datagrams over point-to-point links (IETF RFC 2615) | Protocol | |
| PPP | Point-to-Point Protocol | A method for transporting IP, Ethernet or other services over point-to-point links (IETF RFC 1661) | Protocol | |
| PPS | Pulse per Second | Interface that generates and receives high-quality clock signal at 1 Hz (ITU-T G.703 section 19) | synchronization | Synchronization |
| PRBS | Pseudo Random Bit Sequence | A TDM signal to test network connections. A generator creates a specific test pattern which is sent across a TDM network path. At the termination point, or along the path, a monitor verifies whether the receive stream matches the pattern, and reports any received bit errors. See also BERT. | Test | |
| PRC | Primary Reference Clock | High accuracy and high stability reference clock | synchronization | Synchronization |
| PSN | Packet Switch Network | A networking technology based on packet forwarding | Network | |
| PT | Packet Termination | Generic protocol terminology, often related to IP packet transport on TDM networks. See also EOS, GFP, LAPD, POS and PPP. | protocol | EoS Smart SFP |
| PTP | Precision Time Protocol | A method to distribute highly accurate time across a packet network (IEEE 1588) | synchronization | Synchronization |
| PW | Pseudo Wire | A method to transport various services such as Ethernet, TDM, PDH, and SONET/SDH over packet switched networks (PSNs) using IP or MPLS (IETF RFC 3985) | tdmop | TDM over Packet Solutions Smart SFP |
| RAI | Remote Alarm Indication | Indication that the far-end equipment has detected a network or equipment alarm | Alarm | |
| RDI | Remote Defect Indication | Indication that the far-end equipment has detected a network or equipment defect | Alarm | |
| RoE | Radio over Ethernet | A method to transport CPRI radio signals over a packet network using pseudowire concepts (IEEE 1914.3) | tdmop | TDM over Packet Solutions Smart SFP |
| RTP | Real-time Transport Protocol | A method to provide end-to-end network transport functions suitable for applications transmitting real-time data, such as audio, video or TDM, over a packet network (IETF RFC 3550) | tdmop | TDM over Packet Solutions Smart SFP |
| SASE | Stand Alone Synchronization Equipment | Equipment that generates and distributes high-quality synchronization signals inside a telecom building, often based on high stability oscillators and using GPS as a reference signal | synchronization | Synchronization |
| SAToP | Structure-Agnostic TDM over Packet | A method to transport PDH TDM services in structure-agnostic, transparent mode over a packet network using pseudowire concepts (IETF RC 4553) | tdmop | TDM over Packet Solutions Smart SFP |
| SDH | Synchronous Digital Hierarchy | A networking technology using pre-allocated fixed capacity paths for end-to-end traffic connections; a multiplexing structure with synchronous timing is used to combine multiple paths on a single link | Network | |
| SEC | Synchronous Equipment Clock | The clock function inside SONET/SDH equipment that generates and distributes high-quality synchronization signals on the SONET/SDH network | synchronization | Synchronization |
| SEF | Severely Errored Framing | Indication that 2 or more framing errors were detected in received signal during a time window | Alarm | |
| SES | Severely Errored Second | Indication that during a 1 second interval a high amount of frame errors were detected in received signal | Alarm | |
| SFP | Small Form-factor Pluggable | A pluggable module for optical or electrical network connections to equipment, with a standardized mechanical form factor and standardized electrical interfaces for data and management | Equipment | |
| SNC | Subnetwork Connection | In SDH networks, a connection based on VC-n paths | Protocol | |
| SNCP | Subnetwork Connection Protection | In SDH networks, a 1+1 protected connection based on VC-n paths | Protocol | |
| SOH | Section Overhead | An overhead channel at the section layer in SONET/SDH | channel | Smart SFP |
| SONET | Synchronous Optical NETwork | A networking technology using pre-allocated fixed capacity paths for end-to-end traffic connections; a multiplexing structure with synchronous timing is used to combine multiple paths on a single link | Network | |
| SPE | Synchronous Payload Envelope | The payload area of the STSs or VCs of a SONET connection, typically used for transport of client signals such as Ethernet, IP, MPLS, TDM or PDH | channel | Channelized Network Migration |
| SRTS | Synchronous Residual Time Stamp | A mehod for CES equipment to ensure that the TDM signals are clocked at the same rate at the near- and the far-end of a TDM over Packet connection. The residual timestamp method relies on a common reference clock available at the near- and far-end equipment nodes (ITU-T I.363.1) | tdmop | TDM over Packet Solutions Smart SFP |
| SSF | Server Signal Failure | Indication that a generic failure is present in a higher layer structure of the received signal | Alarm | |
| SSM | Synchronization Status Message | A method to transfer the quality level and status of the local equipment clock to other equipment nodes via messages on a TDM or Packet network link | synchronization | Synchronization |
| SSU | Synchronization Supply Unit | Equipment that generates and distributes high-quality synchronization signals inside a telecom building, often based on high stability oscillators and using GPS as a reference signal | synchronization | Synchronization |
| ST3 | Stratum 3 | A network reference clock with quality and stability according Stratum level 3, also defined are ST1, ST2, ST3E, and ST4 | synchronization | Synchronization |
| STM-1 | Synchronous Transfer Mode level 1 | An SDH fiber connection operating at 155.52 Mb/s | channel | Transparent Network Migration |
| STM-n | Synchronous Transfer Mode level n | An SDH fiber connection operating at n * 155.52 Mb/s. STM-0, STM-1, STM-4, STM-16, STM-64 and STM-192 are defined. | channel | Transparent Network Migration |
| STS-3 | Synchronous Transport Signal level 3 | The payload area of a SONET connection, providing a transport capacity of about 50 Mb/s | channel | Channelized Network Migration |
| STS-n | Synchronous Transport Signal level n | The payload area of a SONET connection, providing a transport capacity of about n * 50 Mb/s | channel | Channelized Network Migration |
| STS-nc | Contiguous Concatenation of N STS-1 SPEs | The payload area of the SONET connection, bundled as a set of consecutively ordered SPEs | channel | Ethernet over SONET SDH |
| SYNC | Synchronization | A generic concept to enable multiple equipment node in a network to operated in time synchronous mode. See also NTP, PTP, SyncE | synchronization | Synchronization |
| SyncE | Synchronous Ethernet | A method to distribute highly accurate frequency reference across a packet network using the Ethernet physical layer (ITU-T G.8261) | synchronization | Synchronization |
| T1 | T carrier signal at the DS-1 rate | A TDM transport link operating at 1 544 kb/s. | channel | Transparent Network Migration |
| T3 | T carrier signal at the DS-3 rate | A TDM transport link operating at 44 736 kb/s. | channel | Channelized Network Migration |
| TDEV | Time Deviation | A method to characterize the quality and performance of a TDM signal using statistical analysis of the phase stability of the signal over a given time interval | synchronization | Synchronization |
| TDM | Time Division Multiplexing | A generic method the multiplex serial signals where each signal is allocated a time-slot. See also OTN, PDH, SDH, SONET | Network | |
| TDMoP | TDM over Packet | A method to transport TDM signals across a packet network. Also known as tdmop and CEM. | tdmop | TDM over Packet Solutions Smart SFP |
| TPoP SFP | Transparent PDH over Packet | A Smart SFP with E1 or T1/DS1 electrical interface, supporting single channel transparent packet transport via SAToP protocol | Smart SFP | Smart SFP |
| TIM | Trace Identifier Mismatch | Indication that the received trail trace identifier (J0, J1, J2) does not match with the expected identifier, in SONET/SDH equipment | Alarm | |
| TSoP | Transparent SONET/SDH over Packet | A method to transport SONET/SDH signals in transparent mode over a packet network using pseudowire concepts similar to SAToP (IETF draft manhoudt pwe3 tsop) | tdmop | TDM over Packet Solutions Smart SFP |
| TSoP SFP | Transparent SONET/SDH over Packet | A Smart SFP with OC3/STM1, or OC12/STM4 or OC48/STM16 optical interface, supporting single channel transparent packet transport via TSoP protocol | Smart SFP | Smart SFP |
| TU | Tributary Unit | The payload area of an SDH lower order signal, including structure information. | channel | Channelized Network Migration |
| TUG-n | Tributary Unit Group, level n | A bundle of TUs combined in a Group | channel | Channelized Network Migration |
| TU-n | Tributary Unit, level n | The payload area of an SDH lower order signal, including structure information. TU1, TU2, TU 12, and TU3 are defined. | channel | Channelized Network Migration |
| UAS | Unavailable Seconds | Indication reporting the amount of seconds the service was unavailable | Alarm | |
| UPSR | Unidirectional Path Switched Ring | Using 2 diversely switched paths on a SONET ring topology to increase the availibility of connections, through protection against fiber, ring network, node or operator failures. | Protocol | |
| VC | Virtual Container | The payload area of an SDH connection, typically used for transport of client signals such as Ethernet, IP, MPLS, TDM or PDH | channel | Channelized Network Migration |
| VC-n | Virtual Container Level n | VC-11, VC-12, VC-2, VC-3, and VC-4 are defined | channel | Channelized Network Migration |
| VC-n-xc | Contiguous Concatenation of X Virtual Containers at Level n | The payload area of an SDH connection, bundled as a set of consecutively ordered VCs | Channel | |
| VCAT | Virtual ConcATenation | The capacity of the SONET/SDH payload area is increased by bundling a set of SPEs or VCs | Channel | |
| VCG | Virtual Concatenation Group | A group or bundle of VCs or SPEs using VCAT | Channel | |
| VCoP SFP | Virtual Container over Packet Smart SFP | A Smart SFP with DS3 or OC3/12 line interface, with embedded multiplexer supporting packet transport for up to 12 STS1 SPE1 channels via CEP protocol | Smart SFP | Smart SFP |
| VT | Virtual Tributary | The payload area of a SONET connection, typically used for transport of client signals such as Ethernet, IP, MPLS, TDM or PDH | channel | Channelized Network Migration |
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