RFC Editor Abbreviations List June 2007 ---------------------------------------------------------------------- It is common in technical writing to abbreviate complex technical terms by combining the first letters. The resulting abbreviations are often called acronyms. Editorial guidelines for the RFC series generally require expansion of these appreviations on first occurrence in a title, in an abstract, or in the body of the document. The RFC Editor attempts to keep the use of abbreviations consistent and to point out conflicts to authors. For this purpose, we have built the abbreviation list below. This list contains abbreviations appearing in RFCs and often reflects discussions with authors, WG chairs, and/or ADs. There is no claim of completeness. Note that some abbreviations have multiple expansions. Some abbreviations are so well known that expansion is probably unnecessary. The RFC Editor exercises editorial judgment about whether a particular use of one of the "well-known" abbreviations requires expansion. (For example, strict adherence to the expansion requirement can lead to impossibly ugly titles.) In the following list of abbreviations, those that are usually (but not necessarily) treated as "well known" are marked with asterisks. However, since there are so many different abbreviations and there is a range of knowledge among RFC readers, we tend to expand abbreviations in case of doubt. Finally, this list includes some terms that look like abbreviations but are actually fixed names for things, and hence cannot and should not be expanded. These are noted as "No expansion". ---------------------------------------------------------------------- 3PCC - Third Party Call Control (3PCC) 3GPP IMS - Third Generation Partnership Project Internet Multimedia System or - Third Generation Partnership Project IP Multimedia Subsystem AAA - Authentication, Authorization, and Accounting (AAA) AAC - Advanced Audio Coding (AAC) AAL5 - ATM (Asynchronous Transfer Mode) Adaptation Layer 5 (AAL5) *ABNF - Augmented Backus-Naur form ABR - Area Border Router (ABR) AC - Access Controller (AC) or - Attachment Circuit (AC) (See RFCs 3985 and 4719) ACK - Acknowledge or acknowledgment No expansion -- not abbreviation ACL - Access Control List (ACL) ADISC - Address Disconvery Extended Link Service (ADISC) Pronounced "ay-disk". ADM - Add-Drop Multiplexer (as in SONET ADM) ADS - Astrophysics Data System (ADS) AES - Advanced Encryption Standard (AES) AH - Authentication Header (AH) AIMD - Additive Increase Multiplicative Decrease (AIMD) AIS - Alarm Indication Signal (AIS) AKA - Authentication and Key Agreement (AKA) AMEI - Association of Musical Electronics Industry (AMEI) AMID - Additive Increase Multiplicative Decrease (AMID) AMR - Adaptive Multi Rate (AMR) AMR-WB - Adaptive Multi Rate - WideBand (AMR-WB) *ANSI - American National Standards Institute *API - Application Programming Interface APM - Application Performance Measurement (APM) ARP - Address Resolution Protocol (ARP) AS - Autonomous System (AS) or - Applicability Statement (AS) Both usages are well known, but still ambiguous ASBR - Autonomous System Border Router (ASBR) *ASCII - American Standard Code for Information Interchange ASE - Autonomous System External (ASE) or - amplifier spontaneous emission (ASE) ASIC - Application-specific Integrated Circuit (ASIC) ASM - Any-Source Multicast (ASM) ASON - Automatic Switched Optical Network *ATM - Asynchronous Transfer Mode (ATM) - Automatic Teller Machine (ATM) ATU - ADSL Tranceiver Unit (ATU) AVP - attribute-value pair (AVP) AVT - Audio/Video Transport AXFR - Asynchronous Full Transfer (AXFR) B2BUA - back-to-back user agent (B2BUA) BCH - typically not expanded. as in "BCH code" (BCH = Bose, Ray-Chaudhuri, Hocquenghem) BECN - Backward Explicit Congestion Notification (BECN) BEEP - Blocks Extensible Exchange Protocol (BEEP) BER - Basic Encoding Rules or - bit error rate (RFC 4837) BFCP - Binary Floor Control Protocol (BFCP) BFD - Bidrectional Forwarding Detection (BFD) *BGP - Border Gateway Protocol B-ISDN - Broadband Integrated Services Digital Network (B-ISDN) *BNF - Backus-Naur form BNG - Broadband Network Gateway (BNG) *BOF - Birds of a Feathe BR - Border Router (BR) BRAS - Broadband Remote Access Server (BRAS) BRI - Basic Rate Interface (BRI) BSM - Bootstrap Message (BSM) BSO - Basic Security Option (BSO) BSR - Bootstrap Router (BSR) BSSID - Basic Service Set Identifier (BSSID) CA - certification authority (CA) CAC - Connection Admission Control (CAC) CALS - Computer-Aided Acquisition and Life-Cycle Support (CALS) CAM - Content Addressable Memory (CAM) CAPWAP - Control and Provisioning of Wireless Access Points (CAPWAP) CAVE - Cellular Authentication and Voice Encryption (CAVE) CBC - Cipher Block Chaining (CBC) CBC-MAC - Cipher Block Chaining Message Authentication Code (CBC-MAC) CCID - Congestion Control Identifier (CCID) CCM - Counter with CBC-MAC (CCM) CCMP - Counter Mode with CBC-MAC Protocol (CCMP) ccTLD - Country Code Top Level Domain (ccTLD) CDF - Comma-Delimited Format or - cumulative distribution function (CDF) *CDMA - Code Division Multiple Access CDMA2000 - Not expanded. It is a registered trademark of the Telecommunications Industry Association in the US. CDN - Call-Disconnect-Notify (CDN) CE - Congestion Experienced (CE) or - Customer Edge (CE) CELP - Coded Excited Linear Prediction (CELP) CEP - Circuit Emulation over Packet (CEP) CES - Circuit Emulation Service (CES) CFB - Cipher FeedBack (CFB) CGI - Common Gateway Interface (CGI) CHAP - Challenge Handshake Authentication Protocol (CHAP) CIDR - Classless Inter-Domain Routing (CIDR) CIPSO - Common Internet Protocol Security Option (CIPSO) CLEI - Common Language Equipment Identifier (CLEI) CLI - command line interface (CLI) or - Call Level Interface (CLI) CLNP - Connectionless Network Protocol (CLNP) CLP - Cell Loss Priority (CLP) (See RFC 4594) A flag in an ATM cell CMC - Certificate Management over CMS (CMC) (See RFC 2797) CMS - Cryptographic Message Syntax (CMS) CMTS - cable modem termination system (CMTS) CN - Client Node (CN) or correspondent node (CN) COPS - Common Open Policy Service (COPS) Corba - common object request broker architecture (Corba) CoS - Class of Service (CoS) CPE - Customer Premises Equipment (CPE) (RFC 4837) CRC - Cyclic Redundancy Check (CRC) CR-LDP - Constraint-based Routed Label Distribution Protocol (CR-LDP) CRISP - Cross Registry Internet Service Protocol (CRISP) CRL - Certificate Revocation List (CRL) *CRLF - Carriage-Return Line-Feed (ASCII control character sequence) CRMF - Certificate Request Message Format (CRMF) cRTP - compressed RTP (cRTP) CSMA/CD - Carrier Sense Multiple Access with Collision Detection (CSMA/CD) CSPF - Constrained Shortest Path First (CSPF) CSRC - contributing source (CSRC) CT_IU - Common Transport Information Unit (CT_IU) CTR - Counter Mode (CTR) CTS - clear to send (CTS) CUG - Closed User Group (CUG) DA - Destination Address (DA) DAD - Duplicate Address Detection (DAD) DARPA - Defense Advanced Research Projects Agency (DARPA) DCCP - Datagram Congestion Control Protocol (DCCP) DCE - Data Communications Equipment (DCE) or - Distributed Computing Environment (DCE) DCOM - Distributed Component Object Model (DCOM) DDoS - Distributed Denial of Service (DDoS) DE - Discard Eligible (DE) Flag in a Frame Relay frame; see RFC 4594. DELT - Dual Ended Loop Test (DELT) DER - Distinguished Encoding Rules *DES - Data Encryption Standard (DES) *DHCP - Dynamic Host Configuration Protocol (DHCP) DHCPv6 - Dynamic Host Configuration Protocol for IPv6 (DHCPv6) DIT - Directory Information Tree (DIT) DLCI - Data Link Connection Identifier (DLCI) DLSw - Data Link Switching (DLSw) (See RFC 4594) A forwarding mechanism for the IBM SNA (Systems Network Architecture). It places SNA NPDUs into a TCP connection between two routers, which tunnel them across an IP network. DN - Distinguished Name (DN) *DNS - Domain Name System DNSSEC - DNS Security (DNSSEC) DoS - Denial of Service (DoS) *DDoS - Distributed denial of service DR - designated router (DR) DS - Diffserv (DS) - Differentiated Services (DS) (RFC 2474) DSA - Digital Signature Algorithm (DSA) DSACK - Duplicate Selective Acknowledgement (DSACK) DSAP - Destination Service Access Point (DSAP) DSCP - Differentiated Services Code Point (DSCP) DSE - DSA-Specific Entry (DSE) *DSL - Digital Subscriber Line (DSL) DSP - Digital Signal Processor (DSP) or - Digital Signal Processing (DSP) DSS - Digital Signature Standard (DSS) *DTD - Document Type Definition DTE - Data Terminal Equipment (DTE) DTLS - Datagram Transport Layer Security (DTLS) DTMF - dual tone multi-frequency (DTMF) DUID - DHCP Unique Identifier (DUID) DUNS - Data Universal Numbering System (DUNS) DUT - Device Under Test (DUT) EAP - Extensible Authentication Protocol (EAP) *EBCDIC - Extended Binary Coded Decimal Interchange Code (EBCDIC) eBGP - External Border Gateway Protocol (eBGP) EC2N - elliptic curve group over GF[2^N] (as in EC2N group) ECC - Elliptic Curve Cryptography (ECC) ECDSA - Elliptic Curve Digital Signature Algorithm (ECDSA) ECM - Error Correction Mode (ECM) ECMP - Equal Cost Multi-Path (ECMP) or - Electronic Commerce Messaging Protocol (ECMP) EC2N - Elliptic Curve Group over GF[2^N] (as in EC2N group) ECN - Explicit Congestion Notification (ECN) ECP - Elliptic Curve Group over GF[P] (as in ECP group) or - Electronic CodeBook (ECP) ECT - ECN-Capable Transport (ECT) EDGE - Enhanced Data rates for GSM Evolution (EDGE) EFCI - Explicit Forward Congestion Indication (EFCI) EFM - Ethernet First Mile (EFM) (RFC 4837) EFR - Enhanced Full Rate (EFR) *EGP - Exterior Gateway Protocol EHLO - Extended Hello (EHLO) ENUM - there is no specific expansion. Refers generally to a telephone numbering plan. However, the term ENUM is universal, whereas Telephone Number Mapping is not. There are ENUM activities and organizations all over the world. The "long name" of the ENUM WG long name is the anomaly, because ENUM is not an abbreviation, despite appearances. *EOF - End of File (EOF) EPON - Ethernet Passive Optical Network (EPON) (RFC 4837) EPP - Extensible Provisioning Protocol (EPP) ERE - Extended Regular Expressions (ERE) ERO - Explicit Route Object (ERO) *ESMTP - Extended Simple Mail Transfer Protocol ESN - Electronic Serial Number (ESN) ESO - Extended Security Option (ESO) ESP - Encapsulating Security Payload (ESP) *ETSI - European Telecommunications Standards Institute (ETSI) EUI - Extended Unique Identifier (EUI) EVRC - Enhanced Variable Rate CODEC (EVRC) FAN ELS - Fabric Address Notification Extended Link Service (FAN ELS) Pronounced "fan ee el es". FARP - Fibre Channel Address Resolution Protocol (FARP) Pronounced "farp". FCAPS - Fault, Configuration, Accounting, Performance, and Security (FCAPS) FCI - Feedback Control Information (FCI) FCIP - Fibre Channel Over TCP/IP (FCIP) FCP - Fibre Channel Protocol (FCP) FCS - Frame Check Sequence (FCS) or - Forwarding Equivalence Class (FEC) [MPLS; see RFC 3031] FEC - Forward Error Correction (FEC) FECN - Forward Explicit Congestion Notification (FECN) FF - Fixed-Filter (FF) FFT - Fast Fourier Transform (FFT) FIN - Not expanded (TCP flag bit name; see SYN) FPGA - Field Programmable Gate-Array (FPGA) FQDN - Fully-Qualified Domain Name (FQDN) FRR - Fast Reroute (FRR) FSM - Finite State Machine (FSM) FSPF - Fabric Shortest Path First (FSPF) *FTP - File Transfer Protocol GARP - Generic Attribute Registration Protocol (GARP) GbE - Gigabit Ethernet (GbE) GCM - Galois/Counter Mode (GCM) GMII - Gigabit Media Independent Interface (GMII) (RFC 4837) *GMPLS - Generalized Multi-Protocol Label Switching GMRP - GARP Multicast Registration Protocol (GMRP) GPRS - General Packet Radio Service (GPRS) GRE - Generic Routing Encapsulation (GRE) GRUU - Globally Routable User Agent URI (GRUU) GSAKMP - Group Secure Association Key Management Protocol (GSAKMP) GSE - Generalized Structure Element (GSE) GSI - Grid Security Infrastructure (GSI) GSM - Global System for Mobile Communications (GSM) GSS-API - Generic Security Service Application Program Interface (GSS-API) GSTN - Global Switched Telephone Network (GSTN) GTK - Group Temporal Key (GTK) gTLD - Generic Top Level Domain (gTLD) GTP - Generic Tunneling Protocol (GTP) GTSM - Generalized TTL Security Mechanism (GTSM) GUI - Graphical User Interface (GUI) GUID - Globally Unique Identifier (GUID) GVRP - Generic VLAN Registration Protocol (GVRP) HBA - Host Bus Adapter (HBA) or - Host-Based Authentication (HBA) HDLC - High-Level Data Link Control (HDLC) HFC - Hybrid Fiber Coaxial (HFC) HMAC - Hashed Message Authentication Code (HMAC) HoA - Home Address (HoA) *HTTP - HyperText Transfer Protocol *HTML - HypterText Markup Language *IAB - Internet Architecture Board *IANA - Internet Assigned Numbers Authority ICE - Interactive Connectivity Establishment (ICE) *ICMP - Internet Control Message Protocol ICRP - Incoming-Call-Reply (ICRP) ICRQ - Incoming-Call-Request (ICRQ) ICSA - International Computer Security Association (ICSA) ICV - Integrity Check Value (ICV) IDS - Intrusion Detection System (IDS) IE - Information Element (IE) *IEEE - Institute of Electrical & Electronics Engineers *IETF - Internet Engineering Task Force IF - intermediate frequency (IF) *iff - if and only if (from mathematical logic) *IGP - Interior Gateway Protocol (IGP) IGMP - Internet Group Management Protocol IKE - Internet Key Exchange Protocol (IKE) ILMI - Integrated Local Management Interface (ILMI) *IMAP - Internet Message Access Protocol IMPP - Instant Messaging and Presence Protocol (IMPP) IMS - IP Multimedia Subsystems (IMS) IMSI - International Mobile Subscriber Identity (IMSI) INCITS - INternational Committee for Information Technology Standards IOS - Internetwork Operating System (IOS); as in Cisco IOS *IP - Internet Protocol IPBX - IP Private Branch Exchange (IPBX) IPCP - IP Control Protocol (IPCP) IPHC - IP Header Compression (IPHC) IPPM - IP Performance Metrics (IPPM) *IPsec - IP Security (IPsec) IPTV - Not expanded. A service that delivers television signals over an RTP/UDP/IP video stream. It is read "IP TV". *IPv4 - Internet Protocol version 4 (RFC 791) *IPv6 - Internet Protocol version 6 IPX - Internetwork Packet Exchange (IPX) IR - Initiation and Refresh (IR) *IS-IS - Intermediate System to Intermediate System (routing protocol) ISAKMP - Internet Security Association and Key Management Protocol (ISAKMP) ISATAP - Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) iSCSI - Internet Small Computer System Interface (iSCSI) *ISDN - Integrated Services Digital Network (ISDN) *ISO - International Organization for Standardization *ISP - Internet Service Provider ISUP - ISDN User Part (ISUP) *ITU - International Telecommunication Union *ITU-T - ITU Telecommunication standardization sector IU - Information Unit (IU) IV - Initialization Vector (IV) IVL - Independent VLAN Learning (IVL) IVR - Interactive Voice Response (IVR) KDC - Key Distribution Center (KDC) KINK - Kerberized Internet Negotiation of Keys (KINK) L2F - Layer 2 Forwarding (L2F) L2TP - Layer 2 Tunneling Protocol (L2TP) L3VPN - Layer 3 Virtual Private Network (L3VPN) *LAN - Local Area Network (LAN) LCCE - Logical Cluster Computing Environment (LCCE) or - L2TP Control Connection Endpoint (See RFCs 3931 and 4719) LCI - Location Configuration Information (LCI) (See RFC 4676) LDAP - Lightweight Directory Access Protocol (LDAP) LDP - Label Distribution Protocol (LDP) LER - Label Edge Router (LER) LIP - Loop Initialization Primitive Sequence (LIP) Pronounced "lip". LLC/SNAP - Logical Link Control/Subnetwork Access Protocol (LLC/SNAP) Pronounced "el el see snap". LLID - Logical Link Identifier (LLID) (RFC 4837) LMDS - Local Multipoint Distribution Service (LMDS) LMP - Link Management Protocol (LMP) LRU - Least Recently Used (LRU) LSA - Link State Advertisement (LSA) LSAP - Link Service Access Point (LSAP) LSB - Least Significant Bit (LSB) LSC - Lambda Switch Capable (LSC) or - Link State Control (LSC) LSDB - Link State Database (LSDB) LSP - Label Switched Path (LSP) LSR - Label Switching Router (LSR) LSRR - Loose Source and Record Route (LSRR) LSW - Least Significant Word (LSW) LUN - Logical Unit Number (LUN) MAC - Message Authentication Code (MAC) or - Medium Access Control (MAC) or - Media Access Control (MAC) MA/RA - Maintenance Agency/Registration Authority (MA/RA) MC - Motion Compensation (MC) MCMS - Multimedia Cable Network System (MCNS) MD5 - MD5 (Message Digest 5) Typically not expanded. See RFC 4635 MED - Multi-Exit Discriminator (MED) MFIB - Multicast Forwarding Information Base (MFIB) MGC - Media Gateway Controller (MGC) MGCP - Media Gateway Control Protocol (MGCP) *MIB - Management Information Base MIC - Message Integrity Check (MIC) or - Message Integrity Code (MIC) MIDCOM - Middlebox Communications (midcom) MIDI - MIDI (Musical Instrument Digital Interface) Typically not expanded. If expand, make MIDI primary, that is, use "MIDI (Musical Instrument Digital Interface)", not "Musical Instrument Digital Interface (MIDI)". (per RFC Editor note for RFCs 4695 and 4696) MIKEY - Multimedia Internet KEYing (MIKEY) *MIME - Multipurpose Internet Mail Extensions MIN - Mobile Identification Number (MIN) MKI - Master Key Identifier (MKI) MLDv2 - Multicast Listener Discovery Version 2 (MLDv2) MLPP - Multilevel Precedence and Preemption (MLPP) MMA - MIDI Manufacturers Association MMS - Multimedia Messaging Service (MMS) MN-FA - Mobile Node - Foreign Agent (MN-FA) MOBIKE - IKEv2 Mobility and Multihoming (MOBIKE) MODP - modular exponentiation group (as in MODP group) MP2PE - Multi-Point to Point Emulation (MP2PE) (RFC 4837) *MPEG - Motion Picture Experts Group Normally not expanded. *MPLS - Multiprotocol Label Switching Use "Multiprotocol" wherever "Multi Protocol" or "MultiProtocol" occur (see RFC 3031, et al.) MRIB - Multicast Routing Information Base (MRIB) MRTG - Multi Router Traffic Grapher (MRTG) MRU - Maximum Receive Unit (MRU) MSA - Message Submission Agent (MSA) MSDP - Multicast Source Discovery Protocol (MSDP) MSS - Maximum Segment Size (MSS) MSW - Most Significant Word (MSW) MTA - Mail Transport Agent (MTA) or - Mail Transfer Agent (MTA) *MTU - Maximum Transmission Unit MUA - Mail User Agent (MUA) or - Message User Agent (MUA) NAI - Network Access Identifier (NAI) NAPT - Network Address Port Translation (NAPT) NAPTR - Naming Authority Pointer (NAPTR) *NAT - Network Address Translation (NAT) or - Network Address Translator (NAT) NAT-T - Network Address Translation Traversal (NAT-T) NBMA - Non-Broadcast Multi-Access (NBMA) NCP - Network Control Protocol (NCP) NCS - Network Control Signaling (NCS) NETCONF - Network Configuration Protocol (NETCONF) - don't expand in titles, but expand in abstract NEWPRED - Not expanded. - Refers to error resilience in MPEG-4 version 2 regarding which frame should be used as the reference for the next prediction. NIC - Network Interface card (NIC) NID - Network Interface device (NID) or Network Identifier (NID) NIS - Network Information Service (NIS) NIST - National Institute of Standards and Technology (NIST) NMP - Network Musical Performance (NMP) NNTP - Network News Transfer Protocol (NNTP) NOS/OLS - Not_Operational Primitive Sequence / Offline Primitive Sequence (NOS/OLS) *NS - as in "NS simulator" is network simulator, but should not be expanded. NSAP - Network Service Access Protocol (NSAP) NSE - Named Signaling Event (NSE) NSEC - NextSECure (NSEC) *NSF - National Science Foundation NSIS - Next Steps in Signaling (NSIS) NSP - native service processing (NSP) (See RFCs 3985 and 4719) NTFS - New Technology File System (NTFS) *NTP - Network Time Protocol *NTSC - National Television Standards Committee OA - Ordered Aggregate (OA) OAM - Operations and Management (OAM) or - Operations and Maintenance (OAM) OCSP - Online Certificate Status Protocol (OCSP) OFB - Output FeedBack (OFB) OID - Object Identifier (OID) OLT - Optical Line Terminal (OLT) (Server unit of the EPON) (RFC 4837) OMA - Open Mobile Alliance (OMA) OMP - Optical Multi-Point (OMP) (RFC 4837) OPES - Open Pluggable Edge Services (OPES) *OSI - Open Systems Interconnection *OSPF - Open Shortest Path First (routing protocol) OSSI - Open Source Software Institute (OSSI) OTAF - Over-the-Air Functionality (OTAF) OTASP - Over-the-Air Service Provisioning (OTASP) OTP - One Time Password (OTP) OU - Organizational Unit (OU) P2PE - Point-to-Point Emulation (P2PE) (RFC 4837) P2MP - Point-to-Multipoint (P2MP) (RFC 4837) PAC - Proxy Auto-Configuration (PAC) - not typically expanded; e.g., "the PAC file" or "Microsoft PAC" PAD - Peer Authorization Database (PAD) *PAL - Phase Alternation Line PAT - Port Address Translation (PAT) PBX - Private Branch Exchange (PBX) PCM - Pulse Code Modulation (PCM) PCMU - Pulse Coded Modulation Pronounced 'mu-law' Not typically expanded (see RFCs 4733 and 4734) *PDA - Personal Digital Assistant PDC - Personal Digital Cellular (mobile phone standard) Similar to CDMA; should not be expanded. PDH - Plesiochronous Digital Hierarchy (PDH) *PDU - Packet Data Unit or Protocol Data Unit PE - Provider Edge (PE) PGP - Pretty Good Privacy (PGP) PHB - Per Hop Behavior (PHB) PHOP - previous hop (PHOP) PIM - Protocol Independent Multicast (PIM) PIM-SM - Protocol Independent Multicast - Sparse Mode (PIM-SM) PKCS - Public Key Cryptographic System (PKCS) PKI - Public Key Infrastructure (PKI) PKIX - Public Key Infrastructure for X.509 Certificates (PKIX) PLR - Point of Local Repair (PLR) PNNI - Private Network-Network Interface (PNNI) PON - Passive Optical Network (PON) (RFC 4837) POP - Point of Presence (POP) or - Post Office Protocol (POP) POTS - Plain Old Telephone Service *PPP - Point to Point Protocol PPPoA - Point-to-Point Protocol over ATM (PPPoA) PPPoE - Point-to-Point Protocol over Ethernet (PPPoE) PPS - Packets Per Second (PPS) PPTP - Point to Point Tunneling Protocol (PPTP) PRF - Pseudo-Random Function (PRF) PSC - Packet Switch Capable (PSC) or PHB Scheduling Class (PSC) *PSN - Public Switched Network or Packet Switched Network PSTN - Public Switched Telephone Network (PSTN) PTI - Payload Type Identifier (PTI) PTK - Pairwise Transient Key (PTK) PTM - Packet Transfer Mode (PTM) or Pulse-Time Modulation (PTM) PVC - Permanent Virtual Circuit (PVC) PVP - Permanent Virtual Path (PVP) PW - pseudowire PWE3 - Pseudowire Emulation Edge-to-Edge (PWE3) QoP - Quality of Protection (QoP) QoS - Quality of Service (QoS) R2T - request-to-transmit (R2T) RADIUS - Remote Authentication Dial-In User Service (RADIUS) RAID - Redundant Array of Independent Disks (RAID) RAN - Radio Access Network (RAN) RCODE - a special case; do not expand (See RFC 4635) RDDP - Remote Direct Data Placement Protocol (RDDP) RDF - Resource Description Framework (RDF) RDI - Remote Defect Indicator (RDI) RDN - Relative Distinguished Name (RDN) RDS - Resolution Discovery System (RDS) RF - radio frequency (RF) RIB - Routing Information Base (RIB) *RIP - Routing Information Protocol RIPng - Routing Information Protocol Next Generation (RIPng) RJRS - Recovery Journal Receiver Structure (RJRS) RJSS - Recovery Journal Sending Structure (RJSS) RLMI - Resource List Meta-Information (RLMI) (See RFC 4662) RLS - Resource List Server (RLS) (See RFC 4662) ROHC - RObust Header Compression (ROHC) RPC - remote procedure call (RPC) RPF - Reverse Path Forwarding (RPF) RR - Resource Record (RR) or - receiver report (RR) RRO - Record Route Object (RRO) RSAES-OAEP - RSA Encryption Scheme - Optimal Asymmetric Encryption Padding (RSAES-OAEP) RSASSA-PSS - RSA Probabilistic Signature Scheme (RSASSA-PSS) RSSI - Received Signal Strength Indication (RSSI) RSVP - Resource Reservation Protocol (RSVP) RTCP - RTP Control Protocol (RTCP) if RTP in RTCP needs to be expanded, should be expanded as: RTCP - Real-time Transport Control Protocol (RTCP) RTO - retransmission timeout (RTO) *RTP - Real-time Transport Protocol RTS - request to send (RTS) RTSP - Real Time Streaming Protocol (RTSP) RTT - round-trip time (RTT) SA - security association (SA) or Source-Active (SA) or source address (SA) (See RFC 4689) SAID - Security Association ID (See RFC 4131) Historically (back to early drafts "SAId" is being used in MIB object Names, also in enumeration values like "Said" are being used; can leave them as is mainly because: a) NMS vendors and operators are familiar with that syntax for OBJECT names involving SAIDs b) It is risky to make global replace that could lead to SNMP syntax errors on deployment (e.g., global replace of SAId for SAID Fix in DESCRIPTION Clauses ONLY: "(SAID)" instead of "(SAId)" "SAID" instead of "SAId" SAML - Security Assertions Markup Language (SAML) SAN - System Area Network (SAN) SAP - Session Announcement Protocol (SAP) SAR - Segmentation and Reassembly (SAR) SASL - Simple Authentication and Security Layer (SASL) S-BGP - Secure Border Gateway Protocol (S-BGP) SBM - Subnet Bandwidth Manager (SBM) SCCRP - Start-Control-Connection-Reply (SCCRP) SCCRQ - Start-Control-Connection-Request (SCCRQ) SCTP - Stream Control Transmission Protocol (SCTP) SCVP - Simple Certificate Validation Protocol (SCVP) S/D - Source/Destination (S/D) SDES - source description (SDES) SDH - Synchronous Digital Hierarchy (SDH) SDP - Session Description Protocol (SDP) SDU - service data unit (SDU) SECG - Standards for Efficient Cryptography Group (SECG) *SIP - Session Initiation Protocol SIPS - Session Initiation Protocol Secure (SIPS) SLA - Service Level Agreement (SLA) SLI - Set-Link-Info (SLI) (See RFC 3931 - includes hyphens) SLLA - Source Link-Layer Address (SLLA) SLLAO - Source Link-Layer Address Option (SLLAO) SLP - Service Location Protocol (SLP) SMDS - Switched Multimegabit Data Service (SMDS) S/MIME - Secure/Multipurpose Internet Mail Extensions (S/MIME) SMIv2 - Structure of Management Information Version 2 (SMIv2) SMPTE - Society of Motion Picture and Television Engineers (SMPTE) *SMS - Short Message Service *SMTP - Simple Mail Transfer Protocol SMUX - SNMP Multiplex (SMUX) SNA - Systems Network Architecture (SNA) (See RFC 4594) SNMP - Simple Network Management Protocol (SNMP) SNP - Subnetwork Point (SNP) SNR - Signal-to-Noise Ratio (SNR) SNTP - Simple Network Time Protocol (SNTP) SOAP - Simple Object Access Protocol (SOAP) But "a Web services messaging protocol; originally the acronym for Simple Object Access Protocol, the term is no longer defined in common use" -IEEE Computer Society SONET - Synchronous Optical Network (SONET) SPE - Synchronous Payload Envelope (SPE) SPF - Sender Policy Framework (SPF) SPI - Security Parameter Index (SPI) SPVC - Switched Permanent Virtual Circuit (SPVC) SR - sender report (SR) SRLG - Shared Risk Link Group (SRLG) SRP - Secure Routing Protocol (SRP) SRTP - Secure Realtime Transport Protocol (SRTP) or Secure Real-time Transport Protocol (SRTP) (See RFC 3711) SRTCP - Secure Realtime Transport Control Protocol (SRTCP) SRV - Service Record (SRV) SSAP - Source Service Access Point (SSAP) SSH - Secure SHell (SSH) Protocol SSID - Service Set Identifier (SSID) SSL/TLS - Secure Socket Layer/Transport Layer Security (SSL/TLS) SSM - source-specific multicast (SSM) SSPI - Security Support Provider Interface (SSPI) SSRC - synchronization source (SSRC) SSRR - Strict Source and Record Route (SSRR) STP - Spanning Tree Protocol (STP) or Secure Transfer Protocol (STP) STUN - Simple Traversal of the UDP Protocol through NAT (STUN) SUT - System Under Test (SUT) SVC - Switched Virtual Circuit (SVC) SVL - Shared VLAN Learning (SVL) SYN - Not expanded (TCP flag bit name. See FIN) TCAM - Ternary Content-Addressable Memory (TCAM) *TCP - Transmission Control Protocol TDM - Time Division Multiplexer (TDM) or - Time-Division Multiplexing (TDM) *TDMA - Time-Division Multiple Access See also CDMA TE - Traffic Engineering or - Traffic Engineered (TE) TED - Traffic Engineering Database (TED) TFRC - TCP Friendly Rate Control (TFRC) TGS - Ticket-Granting Server (TGS) or - Ticket-Granting Service (TGS) TGT - Ticket-Granting Ticket (TGT) TLD - Top-Level Domain (TLD) TLLA - Target Link-Layer Address (TLLA) TLS - Transport Layer Security (TLS) *TLV - Type-Length-Value (self-describing data) TPDU - Transport Protocol Data Unit (TPDU) TS - Traffic Selector (TS) TSN - Trunk Switched Network (TSN) or - Test Support Network (TSN) TTL - Time to Live (TTL) TPM - Transport Performance Metrics (TPM) UA - User Agent (UA) UAC - User Agent Client (UAC) UAM - Universal Access Method (UAM) UAS - User Agent Server (UAS) UDDI - Universal Description, Discovery, and Integration (UDDI) *UDP - User Datagram Protocol UDPTL - UDP Transport Layer (UDPTL) UDVM - Universal Data/Voice Multiplexer (UDVM) UID - Unique Identifier (UID) ULP - Unequal Loss Protection (ULP) UMA - Unlicensed Mobile Access (UMA) UML - Unified Modeling Language (UML) UMTS - Universal Mobile Telecommunications System (UMTS) UNI - User Network Interface (UNI) *URI - Uniform Resource Identifier *URL - Uniform Resource Locator *USB - Universal Serial Bus *UTC - Coordinated Universal Time *UTF-8 - Unicode transformation format 8. UUID - Universally Unique Identifier (UUID) VACM - View-based Access Control Model (VACM) VC - Virtual Circuit (VC) VCC - Virtual Channel Connection (VCC) VCI - Virtual Channel Identifier (VCI) or - Virtual Circuit Identifier (VCI) VDL - Valid Data Length (VDL) VDSL - Very high bit-rate Digital Subscriber Line (VDSL) or - Very high speed Digital Subscriber Line (VDSL) *VLAN - Virtual Local Area Network VMR - Variable Multi Rate WideBand (VMR) VoIP - Voice over IP (VoIP) VPC - Virtual Path Connection (VPC) VPI - Virtual Path Identifier (VPI) VPIM - Voice Profile for Internet Mail (VPIM) VPN - Virtual Private Network (VPN) VRRP - Virtual Router Redundancy Protocol (VRRP) VXML - Voice XML (VXML) *WAN - Wide Area Networks W-CDMA - Wideband Code Division Multiple Access (W-CDMA) WDM - Wavelength Division Multiplexing (WDM) WebDAV - WWW Distributed Authoring and Versioning (WebDAV) WEP - Wired Equivalent Privacy (WEP) WF - Wildcard-Filter (WF) WFQ - Weighted Fair Queuing (WFQ) (See RFC 4594) WLAN - Wireless Local Area Network (WLAN) WRR - Weighted Round Robin (WRR) (See RFC 3594) WWN - World Wide Name (WWN) WWNN - World Wide Node Name (WWNN) WWPN - World Wide Port Name (WWPN) *XML - EXtensible Markup Language XMPP - Extensible Messaging and Presence Protocol (XMPP) XSD - XML Schema Definition (XSD)