S/MIME: Secure Multipurpose Internet Mail
Secure Multipurpose Internet Mail (S/MIME), a secure version of MIME, is defined to support encryption of email messages. S/MIME provides the following cryptographic security services for electronic messaging applications: authentication, message integrity and non-repudiation of origin and privacy and data security. S/MIME can be used by traditional mail user agents (MUAs) to add cryptographic security services to mail that is sent, and to interpret cryptographic security services in mail that is received. However, S/MIME is not restricted to mail; it can be used with any transport mechanism that transports MIME data, such as HTTP.
Standard Organization: IETF
RFC 2632 and RFC 2633

SABP: Service Area Broadcast Protocol
Service Area Broadcast Protocol (SABP) is a 3G UMTS protocol for information broadcasting services, which allows cellular operators to deliver information such as stock prices, traffic information, weather reports and emergency alerts to mobile users within selected cells of the network.
Standard Organization: 3GPP TS 25.419
3GPP

SAN: Storage Area Network
Storage Area Network (SAN) is a high-speed network or subnetwork whose primary purpose is to transfer data between computer and storage systems. A storage device is a machine that contains nothing but a disk or disks for storing data. A SAN consists of a communication infrastructure, which provides physical connections; and a management layer, which organizes the connections, storage elements and computer systems so that data transfer is secure and robust.

SAP: Service Advertising Protocol
Service Advertising Protocol (SAP), a protocol in the Novell's Netware suite, provides information about what servers are available on the network. SAP is used to inform network clients, via routers and servers, of available network resources and services.
Standard Organization: Novell

SAP: Session Announcement Protocol
Session Announcement Protocol (SAP) is an announcement protocol that is used to assist the advertisement of multicast multimedia conferences and other multicast sessions and to communicate the relevant session setup information to prospective participants.
Standard Organization: IETF
RFC 2974

SAS: Serial Attached SCSI
Serial Attached SCSI (SAS) is an evolutionary replacement for the Parallel SCSI physical storage interface. Serial Attached SCSI offers much faster communication and easier configuration. In addition, Serial Attached SCSI provides device compatibility with Serial ATA and uses similar cabling.
Standard Organization: ANSI

SCCP: Signaling Connection Control Part
Signaling Connection Control Part (SCCP), a routing protocol in the SS7 protocol suite (in layer 4), provides end-to-end routing for TCAP messages to their proper databases. SCCP offers enhancements to MTP level 3 to provide connectionless and connection-oriented network services, as well as to address translation capabilities.
Standard Organization: ITU-T

SCCP: Skinny Client Control Protocol
Skinny Client Control Protocol (SCCP or Skinny) is a Cisco proprietary protocol used between Cisco Call Manager and Cisco VOIP phones. It is also supported by some other vendors. For VOIP solutions, the end station of a LAN or IP-based PBX must be simple to use, familiar and relatively cheap. SCCP defines a simple and easy to use architecture, while the H.323 recommendations produce quite an expensive system. An H.323 proxy can be used to communicate with the Skinny Client using the SCCP.
Standard Organization: Cisco

SCP: Session Control Protocol
Session Control Protocol (SCP), a DECnet protocol, manages logical links for DECnet connections.
Standard Organization: DEC/HP

SCSI: Small Computer System Interface
Small Computer System Interface (SCSI), an ANSI standard, is a parallel interface standard used by Apple Macintosh computers, PCs and many UNIX systems for attaching peripheral devices to computers. SCSI interfaces provide for faster data transmission rates than standard serial and parallel ports. In addition, you can attach many devices to a single SCSI port.
Standard Organization: ANSI

SCSP: Server Cache Synchronization Protocol
Server Cache Synchronization Protocol (SCSP) is designed to solve the generalized cache synchronization/cache-replication problem for distributed protocol entities. SCSP synchronizes caches (or a portion of the caches) of a set of server entities of a particular protocol which are bound to a Server Group (SG). The client/server protocol which a particular server uses is identified by a Protocol ID (PID). SGs are identified by a SGID. The combination PID/SGID identifies both the client/server protocol for which the servers of the SG are being synchronized as well as the instance of that protocol. An example of types of information that must be synchronized can be seen in NHRP using IP where the information includes the registered clients' IP to NBMA mappings in the SG LIS. The algorithm used in SCSP is quite similar to that used in Open Shortest Path First (OSPF) protocol.
Standard Organization: IETF
RFC 2334

SCTP: Stream Control Transmission Protocol
Stream Control Transmission Protocol (SCTP), a part of the Signalling Transport (SIGTRAN) protocol family, was designed to transport PSTN signaling messages (SS7/C7) over IP networks but is capable of broader applications. SCTP is a reliable transport protocol operating on top of a connectionless packet network such as IP. SCTP is designed to address the limitations and complexity of TCP while transporting real time signaling and data such as SS7/C7 over an IP network. SCTP can also run on top of the UDP layer.
Standard Organization: IETF
RFC 2960

SDCP: Serial Data Control Protocol
Serial Data Control Protocol (SDCP), a link control protocol in the PPP suite, is responsible for configuring, enabling and disabling the Serial Data Transport Protocol (SDTP) modules on both ends of the point-to-point link. SDTP together with its associated protocol SDCP was developed for using PPP's many features to provide a standard method for synchronous data compression. STDP and SDTP represent a component of a proposal to use PPP to provide compression of synchronous data in DSU/CSUs.
Standard Organization: IETF
RFC 1963

SDH: Synchronous Data Link Hierarchy
Synchronous Data Link Hierarchy (SDH) is a European standard for data transmission over optical fiber network equivalent to SONET of North America. SDH's basic unit, the STM-1 (Synchronous Transport Module-level 1), operates at 155.52 Mbit/s. Transmission rates of up to 10 Gbit/s can be achieved in today's SDH systems, and the 40 Gbit/s systems are possible. SDH systems are fully compatiable to SONET systems.
Standard Organization: ITU-T
G.707, G. 708 and G.709

SDLC: Synchronous Data Link Control
The Synchronous Data Link Control (SDLC) protocol is an IBM data link layer protocol for use in the Systems Network Architecture (SNA) environment.The data link control Layer provides the error-free movement of data between the Network Addressable Units (NAUs) within a given communication network via the Synchronous Data Link Control (SDLC) Protocol. The flow of information passes down from the higher layers through the data link control Layer and is passed into the physical control Layer.
Standard Organization: IBM

SDP: Session Description Protocol
The Session Description Protocol (SDP) describes multimedia sessions for the purpose of session announcement, session invitation and other forms of multimedia session initiation.Session directories assist the advertisement of conference sessions and communicate the relevant conference setup information to prospective participants. SDP is designed to convey such information to recipients.
Standard Organization: IETF
RFC 2327

SDP: Service Discovery Protocol
The Service Discovery Protocol (SDP or Bluetooth SDP) in the Bluetooth protocol stack provides special means for applications in the Bluetooth environment to discover which services are available and to determine the characteristics of those available services. The SDP defines how a Bluetooth client’s application shell acts to discover available Bluetooth servers’ services and their characteristics. The protocol defines how client can search for a service based on specific attributes without the client knowing anything of the available services. The SDP provides means for discovery of new services become becoming available when the client enters an area where a Bluetooth server is operating. The SDP also provides functionality for detecting when a service is no longer available.
Standard Organization: IEEE
IEEE 802.15.1

SDSL: Single-line Digital Subscriber Line
Single-line Digital Subscriber Line (SDSL), also known as Symmetric Digital Subscriber Line, is one variaton of DSL technologies that provides equal bandwidth for both uploads and downloads. SDSL delivers 1.544 Mbps both downstream and upstream over a single copper twisted pair. The use of a single twisted pair limits the operating range of SDSL to 10,000 feet (3048.8 meters).
Standard Organization: ANSI/ITU

SDSL: Symmetric Digital Subscriber Line
Symmetric Digital Subscriber Line (SDSL), also known as Single-line Digital Subscriber Line, is one variaton of DSL technologies that provides equal bandwidth for both uploads and downloads. SDSL delivers 1.544 Mbps both downstream and upstream over a single copper twisted pair. The use of a single twisted pair limits the operating range of SDSL to 10,000 feet (3048.8 meters).
Standard Organization: ANSI/ITU

SDTP: Serial Data Transport Protocol
Serial Data Transport Protocol (SDTP), a network level protocol in the PPP suite, is used for synchronous serial data compression over a PPP link, provides encapsulation and an associated Serial Data Control Protocol (SDCP) for transporting serial data streams over a PPP link. SDTP together with its associated protocol SDCP were developed for the purpose of using PPP's many features to provide a standard method for synchronous data compression. STDP and SDTP represent a component of a proposal to use PPP to provide compression of synchronous data in DSU/CSUs.
Standard Organization: IETF
RFC 1963

SER: Serialization packet
Serialization packet (SER), a protocol in the Novell NetWare suite, ensures that a single version of NetWare is not being loaded on multiple servers.
Standard Organization: Novell

SGCP: Simple Gateway Control Protocol
Simple Gateway Control Protocol (SGCP), a Cisco protocol for VOIP, is designed for media gateway control and signaling. SGCP controls Voice over IP gateways by an external call control element (called a call-agent). SGCP is not deployed in the real world and is obsoleted by the Media Gateway Control Protocol (MGCP) and Megaco.
Standard Organization: Cisco & Telcordia

SGML: Standardized Generalized Markup Language
Standardized Generalized Markup Language (SGML) is an international standard for the definition of system-independent, device-independent methods of representing text in electronic form. SGML is a metalanguage in which one can define markup languages for documents. XML is derived from SGML and now dwarfs SGML in terms of breadth of application. XML is a profile—a specific subset of SGML—designed to be simpler to parse and process than full SGML, and to have more lightweight internationalization. XML is a simplification of SGML for general-purpose applications.
Standard Organization: ISO
ISO 8879

SGMP: Simple Gateway Monitoring Protocol
Simple Gateway Monitoring Protocol (SGMP) is a network management protocol that was considered for Internet standardization and later evolved into SNMP.
Standard Organization: IETF
RFC 1028

SHDSL: Symmetric High-speed DSL
Symmetric High-speed DSL (SHDSL), also known as G.shdsl, achieves 20% better loop-reach than older versions of symmetric DSL. SHDSL causes much less crosstalk into other transmission systems in the same cable, and multi-vendor interoperability is facilitated by the standardization of this technology. SHDSL systems may operate at many bit-rates, from 192 kbps to 5.7 Mbps, thereby maximizing the bit-rate for each customer. G.shdsl specifies operation via one pair of wires, or for operation on longer loops, two pairs of wire may be used. For example, with two pairs of wire, 1.2 Mbps can be sent over 20,000 feet of 26 AWG wire. SHDSL is best suited to data-only applications that need high upstream bit-rates. Though SHDSL does not carry voice like ADSL, new voice-over-DSL techniques may be used to convey digitized voice and data via SHDSL.
Standard Organization: ITU-T
G.991.2

Single-pair high-speed digital subscriber line
Single-pair high-speed digital subscriber line (SHDSL) is a form of Digital Subscriber Line similar to HDSL but providing T1 or E1 connections over a single twisted-pair copper line. See SHDSL.

S-HTTP: Secure HTTP
Secure HTTP (S-HTTP) is a secure message-oriented communications protocol designed for use in conjunction with HTTP. S-HTTP is designed to coexist with HTTP's messaging model and to be easily integrated with HTTP applications.
Standard Organization: IETF
RFC 2660

Signaling System #7 (SS7)
Signaling System #7 (SS7) is a telecommunications protocol suite, defined by the ITU-T, which is used by telephone companies for interoffice signaling. SS7 uses out-of-band or common-channel signaling (CCS) techniques, which use a separated packet-switched network for the signaling purpose. SS7 is also known as Common Channel Signaling System 7 (CCS7 or C7) outside North America.
Standard Organization: AT-T

SIGTRAN: Signaling Transport
Signaling Transport (SIGTRAN) refers to a protocol stack for the transport of Switched Circuit Network (SCN) signaling protocols (such as SS7/C7 an Q.931) over an IP network. SIGTRAN, an evolution of the PSTN signaling, defines adaptors and a core transport capabilities that blend SS7 and packet protocols to provide users with the best both technologies have to offer. Applications of SIGTRAN include:Internet dial-up remote access, IP telephony interworking with PSTN and other services as identified.
Standard Organization: IETF
RFC 2719

SIMPLE: Session Initiation Protocol for Instant Messaging and Presence Leveraging Extensions
Session Initiation Protocol for Instant Messaging and Presence Leveraging Extensions(SIMPLE) is an open standard instant messaging (IM) and presence protocol suite based on Session Initiation Protocol (SIP). SIMPLE applies the SIP to the problems of: 1) Registering for presence information and receiving notifications when such events occur, for example when a user logs-in or comes back from lunch. 2) Managing a session of real-time messages between two or more participants.
Standard Organization: IETF
RFC 3428

SIP: Session Initiation Protocol
Session Initiation Protocol (SIP) is an application layer control protocol that can establish, modify and terminate multimedia sessions such as Internet telephony calls. SIP can also invite participants to already existing sessions, such as multicast conferences. Media can be added to (and removed from) an existing session. SIP transparently supports name mapping and redirection services, which supports personal mobility; users can maintain a single externally visible identifier regardless of their network location.
Standard Organization: IETF
RFC 3261

SIP: SMDS Interface Protocol
SMDS Interface Protocol(SIP) is used for communications between CPE and SMDS carrier equipment. SIP provides connectionless service across the subscriber network interface (SNI), allowing the CPE to access the SMDS network. SIP is based on the IEEE 802.6 Distributed Queue Dual Bus (DQDB) standard for cell relay across metropolitan-area networks (MANs). SIP consists of three levels. SIP Level 3 operates at the Media Access Control (MAC) sublayer of the data link layer of the OSI reference model. SIP Level 2 operates at the MAC sublayer of the data link layer. SIP Level 1 operates at the physical layer of the OSI reference model.
Standard Organization: Bellcore

SIP-T: SIP for Telephones
Session Initiation Protocol (SIP) for Telephones (SIP-T), previously SIP-BCP-T, is a mechanism that uses SIP to facilitate the interconnection of the PSTN with IP. SIP-T allows traditional IN-type services to be seamlessly handled in the Internet environment. It is essential that SS7 information be available at the points of PSTN interconnection to ensure transparency of features not otherwise supported in SIP. SS7 information should be available in its entirety and without any loss to the SIP network across the PSTN-IP interface. SIP-T defines SIP functions that map to ISUP interconnection requirements.
Standard Organization: IETF
RFC 3372

Skinny
Skinny, also known as Skinney Client Control Protocol (SCCP), is a Cisco proprietary protocol used between Cisco Call Manager and Cisco VOIP phones. It is also supported by some other vendors. For VOIP solutions, the end station of a LAN or IP-based PBX must be simple to use, familiar and relatively cheap. SCCP defines a simple and easy to use architecture, while the H.323 recommendations produce quite an expensive system. An H.323 proxy can be used to communicate with the Skinny Client using the SCCP.
Standard Organization: Cisco

SLIP: Serial Line IP
Serial Line IP (SLIP) is a protocol used for point-to-point serial connections running TCP/IP. SLIP is commonly used on dedicated serial links and sometimes for dialup purposes and is usually used with line speeds between 1200bps and 19.2Kbps. SLIP is useful for allowing mixes of hosts and routers to communicate with one another (host-host, host-router and router-router are all common SLIP network configurations).
Standard Organization: IETF
RFC 1055

SLP: Service Location Protocol
The Service Location Protocol (SLP) provides a scalable framework for the discovery and selection of network services. Using this protocol, computers using the Internet no longer need so much static configuration for network services and network-based applications. This is especially important as computers become more portable, and users less tolerant or less able to fulfill the demands of network system administration.
Standard Organization: IETF
RFC 2165

SMB: Sever Message Block
Server Message Block (SMB) protocol is an IBM protocol for sharing files, printers, serial ports, etc between computers. The SMB protocol can be used over the Internet on top of the TCP/IP protocol or other network protocols, such as Internetwork Packet Exchange (Novell IPX) and NetBEUI.
Standard Organization: IBM

SMDS: Switched Multimegabit Data Service
Switched Multimegabit Data Service (SMDS) is a broadband networking technology, developed by Bellcore and based on the IEEE 802.6 DQDB (Distributed Queue Dual Bus) technology.
Standard Organization: IEEE
IEEE 802.6

SMLCPP: Serving Mobile Location Center Peer to Peer Protocol
Serving Mobile Location Center Peer to Peer Protocol (SMLCPP) is a transport protocol for the communication between the Serving Mobile Location Centers (SMLCs). The main functions of SMLCPP are: 1) allowing an SMLC to ask for and obtain information about Radio Interface Timing (RIT), as known from measurements done by LMUs not under its direct control; 2) allowing an SMLC, that controls deciphering keys in the location area, to sent them to other SMLCs in the same location area.
Standard Organization: ETSI
ETSI GSM 08.31

SMPP: Short Message Peer to Peer
Short Message Peer to Peer (SMPP) is a protocol for exchange short messages between SMS peer entities such as short message service centers. SMPP is often used to allow third parties (e.g. value-added service providers like news organisations) to submit messages, often in bulk.
Standard Organization: Aldiscon/Logica

SMRP: Simple Multicast Routing Protocol
The Simple Multicast Routing Protocol (SMRP) is a transport layer protocol developed to route multimedia data streams over AppleTalk networks. It supports Apple Computer's QuickTime Conferencing (QTC) technology. SMRP provides connectionless, best-effort delivery of multicast datagrams and relies on underlying network layer protocols for services. In particular, SMRP facilitates the transmission of data from a single source to multiple destinations.
Standard Organization: Apple

SMS: Short Message Service
Short Message Services is a mechanism of delivery of short messages over the mobile networks. SMS was originally designed as part of GSM, but is now available on a wide range of networks, including 3G networks. There are two forms of SMS: Short Message Service - Point-to-Point (SMS-PP) and Short Message Service - Cell Broadcast (SMS-CB). The message length is 140 bytes. Larger contents (known as long SMS or concatenated SMS) can be sent segmentedly over multiple messages, in which case each message will start with a user data header (UDH) containing segmentation information.
Standard Organization: 3GPP
GSM 03.40 and GSM 03.41

SMS-CB: Short Message Service - Cell Broadcast
Short Message Service - Cell Broadcast (SMS-CB), a form of Short Message Service for the delivering of short messages over the mobile networks, allows messages (advertising, public information, etc.) to be broadcast to all mobile users in a specified geographical area.
Standard Organization: 3GPP
GSM 03.40

SMS-PP: Short Message Service - Point to Point
Short Message Service - Point to Point (SMS-PP), a form of Short Message Service for the delivering of short messages over the mobile networks, provides, allows messages to be sent from an individual to another.
Standard Organization: 3GPP
GSM 03.40

SMTP: Simple Mail Transfer Protocol
Simple Mail Transfer Protocol (SMTP) is a protocol designed to transfer electronic mails reliably and efficiently. SMTP is a mail service modeled on the FTP file transfer service. SMTP transfers mail messages between systems and provides notification regarding incoming mail.
Standard Organization: IETF
RFC 2821

SNA NAU: Network Accessible Units
Network Accessible Units (NAUs), formerly called "network addressable units", are the IBM Systems Network Architecture (SNA) components to facilitate the communication between a Transaction Program (TP) and the SNA network. NAUs are unique network resources that can be accessed through unique local addresses by other network resources.
Standard Organization: IBM

SNA: System Network Architeture
The Systems Network Architecture (SNA) defined by IBM is one of the most popular network architecture models. Although now considered a legacy networking model, SNA is still widely deployed. SNA was designed around the host-to-terminal communication model that IBM's mainframes use.
Standard Organization: IBM

SNACP: SNA PPP Control Protocol
SNA PPP Control Protocol (SNACP), is responsible for configuring, enabling and disabling SNA on both ends of the point-point link (PPP). SNACP uses the same packet exchange mechanism as the Link Control Protocol (LCP). SNACP packets may not be exchanged until PPP has reached the Network-Layer Protocol phase. SNACP packets received before this phase is reached should be silently discarded. There are two SNA Network Control Protocols; one for SNA over LLC 802.2 and the other for SNA without LLC 802.2.
Standard Organization: IETF
RFC 2043

SNAP: SubNetwork Access Protocol
The SubNetwork Access Protocol (SNAP) is a standard for the transmission of IP datagrams over IEEE 802 networks. In other words, IP datagrams can be sent on IEEE 802 networks encapsulated within the 802.2 LLC and SNAP data link layers and the 802.3, 802.4 or 802.5 physical network layers.
Standard Organization: IEEE
IEEE 802.2

SNDCP: Sub Network Dependent Convergence Protocol
The Sub Network Dependent Convergence Protocol (SNDCP) provides services to the higher layers which may include connectionless and connection-oriented mode, compression, multiplexing and segmentation. SNDCP is used in a number of different technologies. The General Packet Radio Service (GPRS) uses the SNDCP layer services. SNDCP can operate within the Mobile Station (MS) or Serving GPRS Support Node (SGSN) depending on the option selected by the customer.
Standard Organization: ETSI

SNI: Subscriber Network Interface
Subscriber Network Interface (SNI) refers to the TDM access links such as DS0, DS1/T1, DS3/T3, E1, E3 that connects CPE and an SMDS switch of the PSTN network.
Standard Organization: ANSI

SNMP MIB: Simple Network Management Protocol Management Information Base
Simple Network Management Protocol Management Information Base (SNMP-MIB) are managed objects that could be accessed via a virtual information store through the Simple Network Management Protocol (SNMP). Objects in the MIB are defined using the mechanisms defined in the Structure of Management Information (SMI).
Standard Organization: IETF
RFC 3418

SNMP OID: SNMP Object Identifiers
SNMP Object Identifiers (SNMP-OID) are the sequences of integers on the path leading from the root of the tree to a named object. SNMP uses an Object Identifier (OID) to specify the exact parameter to set or get in the tree.
Standard Organization: IETF

SNMP RMON: SNMP Remote Network Monitoring
SNMP Remote Network Monitoring (SNMP-RMON), also known as Remote Monitoring (RMON), is a standard monitoring specification that enables various network monitors and console systems to exchange network-monitoring data. RMON provides network administrators with more freedom in selecting network-monitoring probes and consoles with features that meet their particular networking needs. RMON has two versions: RMON1 and RMON2.
Standard Organization: IETF
RFC 2819 and RFC 2021

SNMP RMON1: SNMP Remote Network Monitoring version 1
SNMP Remote Network Monitoring version 1 (SNMP-RMON1), also known as RMON1, RMONv1, which can now be found on most modern network hardware, defined 9 MIB groups for basic network monitoring.
Standard Organization: IETF
RFC 2819

SNMP RMON2: SNMP Remote Network Monitoring version 2
SNMP Remote Network Monitoring version 2 (SNMP-RMON2), also known as RMON2, is an extension of RMON that focuses on higher layers of traffic above the medium access control (MAC) layer. RMON2 has an emphasis on IP traffic and application level traffic. RMON2 allows network management applications to monitor packets on all network layers.
Standard Organization: IETF
RFC 2021

SNMP SMI: SNMP Structure of Management Information
SNMP Structure of Management Information (SNMP-SMI) is a collection of managed objects, residing in a virtual information store. The SMI is divided into three parts: module definitions, object definitions, and, notification definitions. There are two types of SMI: SMIv1 and SMIv2
Standard Organization: IETF
RFC 1155 v1 and RFC 2578 v2

SNMP: Simple Network Management Protocol
Simple Network Management Protocol (SNMP) is the standard protocol developed to manage nodes (servers, workstations, routers, switches and hubs, etc) on an IP network. SNMP enables network administrators to manage network performance, find, solve network problems and plan for network growth. Network management systems learn of problems by receiving traps or change notices from network devices implementing SNMP.
Standard Organization: IETF
RFC 1157, 1441, 3410

SNMPv1: Simple Network Management Protocol version 1
Simple Network Management Protocol version 1 (SNMPv1) is a simple request/response protocol. The network management system issues a request to the managed devices that return responses. This behavior is implemented by using one of four protocol operations: Get, GetNext, Set and Trap. The Get operation is used by the NMS to retrieve the value of one or more object instances from an agent. If the agent responding to the Get operation cannot provide values for all the object instances in a list, it does not provide any values.
Standard Organization: IETF
RFC 1157

SNMPv2: Simple Network Management Protocol version 2
Simple Network Management Protocol version 2 (SNMPv2) is an evolution of SNMPv1. The Get, GetNext, and Set operations used in SNMPv1 are exactly the same as those used in SNMPv2. However, SNMPv2 adds and enhances some protocol operations. The SNMPv2 Trap operation, for example, serves the same function as that used in SNMPv1 but uses a different message format and is designed to replace the SNMPv1 Trap.
Standard Organization: IETF
RFC 1441

SNMPv3: Simple Network Management Protocol version 3
Simple Network Management Protocol version 2 (SNMPv3) adds security and remote configuration capabilities to the previous versions. The SNMPv3 architecture introduces the User-based Security Model (USM) for message security and the View-based Access Control Model (VACM) for access control. The architecture supports the concurrent use of different security, access control and message processing models.
Standard Organization: IETF
RFC 3410

SNTP: Simple Network Time Protocol
The Simple Network Time Protocol (SNTP) is an adaptation of the Network Time Protocol (NTP) used to synchronize computer clocks on the Internet. SNTP can be used when the ultimate performance of the full NTP implementation is not needed or justified. When operating with current and previous NTP and SNTP versions, SNTP involves no changes to the NTP specification or known implementations, but rather a clarification of certain design features of NTP which allow operation in a simple, stateless remote-procedure call (RPC) mode with accuracy and reliability expectations similar to the UDP/TIME protocol.
Standard Organization: IETF
RFC 2030

SOAP: Simple Object Access Protocol
Simple Object Access Protocol (SOAP) is a lightweight protocol intended for exchanging structured information in a decentralized, distributed environment. It uses XML technologies to define an extensible messaging framework providing a message construct that can be exchanged over a variety of underlying protocols. The framework has been designed to be independent of any particular programming model and other implementation specific semantics.
Standard Organization: W3C

SOCKS
The SOCKS protocol, also known as authenticated firewall traversal (AFT), provides a framework for client-server applications in both the TCP and UDP domains to conveniently and securely use the services of a network firewall. SOCKS enables a proxy server to accept requests from client users in a company's network so that it can forward them across the Internet. SOCKS uses sockets to represent and keep track of individual connections. The client side of SOCKS is built into certain Web browsers and the server side can be added to a proxy server.
Standard Organization: IETF
RFC 1928

SOCKS v5
The SOCKS v5 is the latest version of the SOCKS protocol, which provides a framework for client-server applications in both the TCP and UDP domains to conveniently and securely use the services of a network firewall. SOCKS v5 provides stronger authentication than the SOCKS Version 4. SOCKS v5 extends the SOCKS v4 model to include UDP, and extends the framework to include provisions for generalized strong authentication schemes. It also adapts the addressing scheme to encompass domain-name and IPv6 addresses.
Standard Organization: IETF
RFC 1928

SONET/SDH: Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy (SDH)
The Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy (SDH), often combined as SONET/SDH, are a set of related standards for synchronous data transmission over fiber optic networks that are often used for framing and synchronization at the physical layer. SONET is the United States version of the standard published by the American National Standards Institutue (ANSI). SDH is the international version of the standard published by the International Telecommunications Union (ITU). Transmission rates of up to 10 Gbit/s can be achieved in today's SONET/SDH systems and the 40 Gbit/s systems are possible. SONET/SDH systems are fully compatiable with each other.
Standard Organization: ANSI / ITU-T

SONET: Synchronous Optical Network
The Synchronous Optical Network (SONET), the US version of the standard published by the American National Standards Institutue (ANSI), is a set of standards for synchronous data transmission over fiber optic networks that are often used for framing and synchronization at the physical layer. SONET is based on transmission at speeds of multiples of 51.840 Mbps, or STS-1. SDH is the international version of the standard published by the International Telecommunications Union (ITU). Transmission rates of up to 10 Gbit/s can be achieved in today's SONET systems and the 40 Gbit/s systems are possible. SONET systems are fully compatiable to SDH systems.
Standard Organization: ANSI
ANSI T1.105

SPANS: Simple Protocol for ATM Network Signaling
Simple Protocol for ATM Network Signaling (SPANS) was developed by FORE Systems for use in ATM networks. The protocol specifies the signaling messages that are exchanged between hosts and the ATM network to perform functions such as opening and closing connections. These functions allow hosts and routers to use an ATM LAN as a subnet of a larger internet. In what
follows, the term "network" is used to refer to the network of ATM switches, and is distinct from the end systems that communicate with the network.
Standard Organization: FORE Systems

SPP: Sequenced Packet Protocol in VINES
The Sequenced Packet Protocol (SPP), a transport layer protocol in the VINES protocol stack, provides a reliable virtual connection service for private connections.
Standard Organization: Banyan

SPP: Sequenced Packet Protocol (Xerox)
Sequenced Packet Protocol, a transport layer protocol in the Xerox protocol stack, provides a reliable virtual connection service for private connections.
Standard Organization: Xerox

SPX: Sequenced Packet Exchange
The Sequenced Packet Exchange (SPX) protocol is Novells legacy transport layer protocol providing a packet delivery service for Novell NetWare network. SPX is based on the Xerox Sequenced Packet Protocol (SPP). SPX operates on top of IPX and is used in Novell NetWare (prior to NetWare 5.0) systems for communications in client/server application programs, e.g. BTRIEVE (ISAM manager). SPX performs equivalent functions to TCP. The newer versions of NetWare services are run on top of TCP/IP.
Standard Organization: Novell

SRB: Source Routing Bridging
Source Routing Bridging (SRB) is a method of bridging originated by IBM and popular in Token Ring networks. In an SRB network, the entire route to a destination is predetermined; in real time, prior to the sending of data to the destination. SRBs store and forward the frames as indicated by the route appearing in the appropriate frame field. Since its initial proposal, IBM has offered a new bridging standard: the source-route transparent (SRT) bridging solution. Although SRT bridging has achieved support, SRBs are still widely deployed.
Standard Organization: IBM

SRCP: Simple Resource Control Protocol
Simple Resource Control Protocol(SRCP) is a set of extensions to MGCP to allow the VSC to poll the gateway about its current configuration.
Standard Organization: Cisco

SRP: Spatial Reuse Protocol
Spatial Reuse Protocol (SRP) is the underpinning of Cisco's proprietary metropolitan IP offerings, and will be a key component of the IEEE 802.17 Resilient Packet Ring (RPR).
Standard Organization: Cisco

SRTP: Sequenced Routing Update Protocol
Sequenced Routing Update Protocol (SRTP) is VINES protocol that assists VINES servers in finding neighboring clients, servers, and routers.
Standard Organization: VINES

SS7: Signaling System 7
Signaling System #7 (SS7) is a telecommunications protocol suite, defined by the ITU-T, which is used by telephone companies for interoffice signaling. SS7 uses out-of-band or common-channel signaling (CCS) techniques, which use a separated packet-switched network for the signaling purpose. SS7 is also known as Common Channel Signaling System 7 (CCS7 or C7) outside North America.
Standard Organization: ITU-T

SSCOP: Service Specific Connection Oriented Protocol
Service Specific Connection Oriented Protocol (SSCOP) is a data link layer protocol in the B-ISDN suite that guarantees the delivery of ATM signaling packets. SSCOP is responsible for providing mechanisms for the establishment, release and monitoring of signaling information exchanged between peer signaling entities. SSCOP is positioned within the AAL architecture
Standard Organization: ITU-T
ITU Q.2110

SSH: Secure Shell Protocol
Secure Shell Protocol(SSH) is a Unix-based command interface and protocol for secure remote login and other secure network services over an insecure network. It is widely used by network administrators to control Web and other kinds of servers remotely. SSH is actually a suite of utilities - slogin, ssh, and scp - that are secure versions of the earlier UNIX utilities, rlogin, rsh, and rcp. SSH consists of three major components：(1) Transport Layer Protocol [SSH-TRANS]；(2) User Authentication Protocol [SSH-USERAUTH] ；(3) Connection Protocol [SSH-CONNECT].
Standard Organization: IETF
RFC 4251

SSL/TLS: Secure Socket Layer (SSL) and Transport Layer Security (TLS) Protocol
Secure Socket Layer (SSL) and Transport Layer Security (TLS) Protocol provided privacy and data integrity between two communicating applications. The protocol is composed of two layers: the TLS Record Protocol and the TLS Handshake Protocol. At the lowest level, layered on top of some reliable transport protocol (TCP) is the TLS Record Protocol. SSL was renamed to TLS by IETF. But the SSL name has gained enough popularity, and people still call the protocol SSL or SST/TLS.
Standard Organization: IETF
RFC 2246

SSL: Secure Socket Layer
The Secure Sockets Layer (SSL), a protocol originally defined by Netscape, is a commonly-used protocol for managing the security of a message transmission on the Internet. SSL has been succeeded by Transport Layer Security (TLS). But the SSL name has gained enough popularity, and people still call the protocol SSL or SST/TLS. The protocol is composed of two layers: the TLS Record Protocol and the TLS Handshake Protocol. At the lowest level, layered on top of some reliable transport protocol (TCP) is the TLS Record Protocol. SSL is included as part of both the Microsoft and Netscape browsers and most Web server products.
Standard Organization: IETF
RFC 2246

SSM: Source Specific Multicast
Source Specific Multicast(SSM) is a datagram delivery model that supports one-to-many applications, also known as broadcast applications. SSM is intended to provide unambiguous semantics to the designers of the protocols and host interfaces used in conjunction with source-specific multicast.
Standard Organization: IETF
RFC 3569

SSP: Switch-to-Switch Protocol
Switch-to-Switch Protocol (SSP), specified in the DLSw standard, allows routers to establish DLSw connections, locate resources, forward data, and handle flow control and error recovery.
Standard Organization: IBM

SSRP: Simple Server Replication Protocol
Simple Server Replication Protocol (SSRP), also known as Simple Server Redundancy Protocol, is an ATM LANE Services redundancy protocol. With SSRP, it is possible to have more than one LES/BUS running in a LANE cloud and creates fault-tolerance using standard LANE protocols and mechanisms.
Standard Organization: ATM Forum

STM: Synchronous Transmission Module
Synchronous Transmission Module (STM), also known as Synchronous Transfer Mode, is the basic rate of transmission of the SDH ITU-T fiber optic network transmission standard. It has a bit rate of 155.52 Mbit/s and is the SDH equivalent of an OC-3 (SONET).
Standard Organization: ITU-T

STM-0: Synchronous Transmission Module level zero
Synchronous Transmission Module level zero (STM-0) is the SDH ITU-T fiber optic network transmission standard. It has a bit rate of 51.84 Mbit/s and is the SDH equivalent of an OC-1 (SONET).
Standard Organization: ITU-T

STM-1: Synchronous Transmission Module level one
Synchronous Transmission Module level one (STM-1) is the basic rate of transmission of the SDH ITU-T fiber optic network transmission standard. It has a bit rate of 155.52 Mbit/s and is the SDH equivalent of an OC-3 (SONET).
Standard Organization: ITU-T

STM-4: Synchronous Transmission Module level 4
Synchronous Transmission Module level 4 (STM-4) is one of the transmission mode of the SDH ITU-T fiber optic network transmission standard. It has a bit rate of 622.08 Mbit/s and is the SDH equivalent of an OC-12 (SONET).
Standard Organization: ITU-T

STM-n: Synchronous Transmission Module level n
Synchronous Transmission Module n (STM-n), also known as Synchronous Transfer Mode n, refers to a group of the transmission modes of the SDH ITU-T fiber optic network transmission standard, which is the multiplexing "n" of the STM-1 frames.
Standard Organization: ITU-T

STP: Spanning-Tree Protocol
Spanning-Tree Protocol (STP), as defined in IEEE 802.1D, is a link management protocol that provides path redundancy while preventing undesirable loops in the network. For an Ethernet network to function properly, only one active path can exist between two stations. Loops occur in networks for a variety of reasons. The most common reason for loops in networks is a deliberate attempt to provide redundancy—in case that one link or switch fails, another link or switch can take over.
Standard Organization: IEEE
IEEE 802.1D

StreetTalk
StreetTalk is an application protocol in the VINES protocol stack which maintains a distributed directory of the names of network resources. In VINES network, names are global across the Internet and independent of the network topology.
Standard Organization: Banyan

STS-1: Synchronous Transport Signal level 1
Synchronous Transport Signal level 1(STS-1) is the basic building block signal of SONET, operating at 51.84 Mbps. Faster SONET rates are defined as STS-n, where n is a multiple of 51.84 Mbps.

STS-3c: Synchronous Transport Signal level 3, concatenated
Synchronous Transport Signal level 3, concatenated(STS-3c) is the SONET format that specifies the frame structure for the 155.52-Mbps lines used to carry ATM cells.

SUA: SS7 SCCP-User Adaptation Layer
SS7 SCCP User Adaptation Layer (SUA), a protocol in the SIGTRAN protocol stack, provides SCCP-User signalling over SCTP. SUA is intended to be used on a Provider/User basis where SCCP resides on a Signalling Gateway (SG) and SCCP Users reside on an Application Server (AS).
Standard Organization: IETF
RFC 3868