S
S interface
n. See S/T interface.
S-interface
adj. See S/T interface.
S/T Interface, Adj.
Specifies an ISDN communications device that connects to an external network terminator (NT1).
S/T Interface, N.
The electrical interface between a network terminator (NT1) device and one or more ISDN communications devices that do not contain their own NT1s.
SA Broadband
A family of products that enables a service provider to implement asynchronous transfer mode (ATM) services such as data, voice, and video.
SAM
Secure Access Manager. Secure Access Manager gives network administrators granular control over the security functions of the entire network directly from the central site. Through this Windows-based application, network administrators can configure the Secure Access Firewall(s) off line and download the configuration to remote locations. The menu-driven program enables network administrators to easily configure the firewall on the network.
SAP
Service Access Point
SAP Filters
See NetWare call filters.
SBS
Stimulated Brillouin Scattering
SC/APC
Subscription Channel / Angled Polished Connector
SDH
Synchronous Digital Hierarchy: A standard that defines transmission rates for global high-speed multiplexing.
SDRP
Source Demand Routing Protocol
SDSAF
See Switched Digital Services Applications Forum.
SEP
Sequential Exchange Protocol
SIP
Simple Internet Protocol
SLIP
Serial Line Internet Protocol. The protocol that was made obsolete by Point-to-Point Protocol, for point-to-point serial connections using TCP/IP.
SLIP (Serial Line IP)
A protocol that enables your computer to send and receive IP packets over a serial link.
SMDR
Station Management Detail Recording. The ability of network access equipment to output call statistics and performance information for tabulation and analysis.
SMDS
Switched Multimegabit Data Service. A packet-based network service allowing the creation of high-speed data networks (up to 45 Mbit/s). Now in the testing and initial implementation phases.
SMTP
Simple Mail Transfer Protocol. A protocol for exchanging email messages between servers across a network. SMTP is the principle protocol for sending email over the Internet.
SNAP
SubNetwork Access Protocol
SNMP
Simple Network Management Protocol. A standard way for computers to share networking information. In SNMP, two types of communicating devices exist: agents and managers. An agent provides networking information to a manager application running on another computer. The agents and managers share a database of information, called the Management Information Base (MIB). An agent can use a message called a traps-PDU to send unsolicited information to the manager.
SONET
Synchronous Optical Network. SONET is a Bellcore specification currently used in worldwide public data networks (PDNs). It defines a synchronous optical network-based user-network interface (UNI), either public or private, operating at speeds from 51 Mbps
SPID
Service Profile Identifier. Your ISDN service provider (telephone company) uses this number at the Central Office switch to identify services on your ISDN line. This number is derived from a telephone number. See also Central Office and ISDN.
SQL
Structured query language. A standard interactive and programming language for requesting information from and updating databases.
SS7
Signaling System 7: a signaling method-separate from voice or data channel-that lets Intelligent Network elements exchange information among themselves.
SSL
Secure Sockets Layer. A program layer of network, and also a protocol that enable encrypted and authenticated communications across the Internet. Many websites use SSL protocol to obtain confidential user information.
SVC
Switched Virtual Circuit. A path over a packet-switched network that appears to be a dedicated circuit, but in fact the connection only stays up as long as needed, and then ends. (Also see PVC.)
SW56
See Switched 56.
SWIPE
IP with Encryption
Scalable
Able to be changed in size or configuration to suit changing conditions. For example, a scalable network can be expanded from a few nodes to thousands of nodes.
Screen Pop
In Computer Technology Integration, the appearance of database information about a caller, while the phone is ringing, on the call recipient's computer screen.
Secure Access Firewalls
Secure Access Firewall is a software option for Ascend units that offers a fully integrated firewall security for remote networking. It uses state-of-the-art dynamic firewall technology to deliver a comprehensive security solution for the corporate LAN, remote office LAN and telecommuter's LAN that stops intruders from breaking and entering into networks. Securing the perimeter of the local network where it meets the Internet sets the stage for using the Internet for Intranet applications.
Secure ID
A proprietary brand of security card (about the size of a credit card) that generates a code based on the user’s ID, password, and information in the card. When the user attempts to log on to a secure network, a code is requested that must have been generated within the previous 60 seconds. The server interprets the code, and if it is found to be genuine, the user is granted access.
SecureConnect
The Lucent suite of security features, which provide a complete solution for establishing secure sessions across the Internet. The SecureConnect features work with the Lucent MAX and Pipeline products. SecureConnect Firewall is an ICSA-certified, dynamic firewall technology. SecureConnect Firewall + VPN is an integrated firewall and encryption feature that enables users to conduct authenticated and confidential sessions over the public Internet. SecureConnect Client is PC client software that gives remote and mobile users the same confidential and secure connections that network users enjoy via SecureConnect Pipeline and MAX products. SecureConnect Server is a Web-accessible, RADIUS-based user authentication system.
SecureConnect Firewalls
A software option for Lucent units that offers a fully integrated firewall security for remote networking. It uses state-of-the-art dynamic firewall technology to deliver a comprehensive security solution for the corporate LAN, remote office LAN and telecommuter’s LAN that stops intruders from breaking and entering into networks. Securing the perimeter of the local network where it meets the Internet sets the stage for using the Internet for Intranet applications.
SecureConnect Manager
SecureConnect Manager gives network administrators granular control over the security functions of the entire network directly from the central site. Through this Windows based application, network administrators can configure the SecureConnect Firewall(s) off line and download the configuration to remote locations. The menu-driven program enables network administrators to easily configure the firewall on the network.
Security Cards
See Secure ID.
Selective Acknowledgment (SACK)
An acknowledgement mechanism used with the sliding window protocols that allows the receiver to acknowledge packets received out of order but within the current sliding window.
Semiconductor
A crystalline solid that behaves somewhere between a conductor (like iron) and an insulator (like glass). Semiconductors are the raw materials used in active electronic and optical devices.
Sensitivity
The input level required for a device to provide a predetermined output.
Serial Communication
Communication through the serial port of your computer. For Windows 3.1, the maximum speed of the serial port is 19,200. For Windows 95, the COM port limit on the settings drop-down list is 921,600. These limitations are subject to change as development of a faster serial bus design is implemented.
Serial Connection
A link between the serial ports of two devices.
Serial Host
A device, such as a videoconferencing codec, that is connected to a serial host port communicating over a point-to-point link. To a serial host, the MAX appears to be a cable or DCE (Data Communications Equipment).
Serial Host Port
The V.35, RS-499, or X.21 port on the MAX.
Serial Host Port Module
A module on the MAX that connects to a serial host through its serial host port.
Serial Line IP
A protocol that enables your computer to send and receive IP packets over a serial link.
Serial Number Exchange Protocol (SNEP)
Packets that are used to ensure that one copy of NetWare has not been loaded onto more than one NetWare Server. SNEP packets, by default are NOT filtered and therefore will cause a link to be dialed in a routed IPX environment. SNEP can be call filtered using the same offset rules as an 802.2 or 802.3 frame type, wit its designated socket number. It uses a destination socket of 0457.
Serial Transmission
A form of data transmission in which only one line carries all eight bits of a byte. In serial transmission, one bit follows another (as opposed to parallel transmission, in which the bits travel simultaneously, each on a different wire). Serial transmission can be either synchronous or asynchronous. Synchronous communication requires additional lines for transmitting handshake or timing signals. In asynchronous communication, the data itself contains synchronization information, so neither handshake nor clock signals are necessary.
Serial port
A bidirectional channel through which data flows one bit as a time.
Server
A server is a shared computer on the local area network that can be as simple as a regular PC set aside to handle print requests to a single printer. Or, more commonly, it is the fastest and brawniest PC around. It may be used as a repository and a distributor of oodles of data. It may also be the gatekeeper controlling access to voice mail, electronic mail, and facsimile services.
Service Control Point
An Intelligent Network element. A programmable intelligent database server that contains service intelligence and stores call control and routing instructions for delivery of services.
Service Creation Environment (SCE)
A leading service development system that allows service providers, Lucent Technologies, and selected third-party vendors to create or customize innovative services. Provide the power to develop, test, and implement, via Lucent Technologies Intelligent Network products, breakthrough communication and information services.
Service Management
The ability to create and control data services, enabling fast and cost-effective deployment and ongoing management. For service providers, service management means the ability to create a variety of services targeted for varied enterprise market segments with appropriate traffic management plans and price models. For enterprises, service management means new, public data services targeted and priced for business needs that the enterprise can measure directly with access to network information.
Service Management System
The administration, management, and provisioning server that handles the complexities of delivering services throughout the intelligent network.
Service Node
An element in an advanced public network ing architecture at which service requests, including service switching, are processed.
Service Node Service Control Point (SN-SCP)
A component of the GlobeView[R]-2000 Service Node that provides control functions for the Interface and Services Stage (ISS) and the ATM Interconnect Shelf.
Service Switching Point
In the intelligent network, the node normally associated with the serving office. It recognizes calls requiring special handling and sends them either to the Service Control Point, Service Node.
Session
The state a connection reaches when bothparties can communicate with each other.
Shielded Twisted Pair Cable
STP cable consists of two wires twisted two or more times per inch in order to help cancel out noise. The entire cable has a protective covering. STP cable is typically used in ARCnet and token ring networks.
Short haul
According to some definitions, a distance between several hundred yards and 20 miles.
Shorter Radio Wave
In wireless communications, this wave enables a radio signal to travel through small openings and navigate around physical obstructions that can cause interference.
Shortest Path Routing
A routing algorithm that calculates the path distance to all network destinations. A cost assigned to each link determines the shortest path.
Signal Transfer Point
A packet switching device in the CCS 7 network. See Common Channel Signaling Version 7 (CCS 7).
Signaling ATM Adaptation Layer (SAAL)
The SAAL is a mechanism for ensuring that signaling messages are reliably transported between network peers. It resides between the Asynchronous Transfer Mode (ATM) Layer and Q.2931 in the user’s equipment. The purpose of the SAAL is to provide reliable transport of Q.2931 messages between peer Q.2931 entities, such as an ATM switch and host, over the ATM Layer. The SAAL is subdivided into the Common Part (CP) and the Service-Specific Part (SSP).
Signaling Connection Control Part (SCCP)
Provides connectionless and connection-oriented network services and global title translation (GTT) capabilities above MTP Level 3. A global title is an address (e.g., a dialed 800 number, calling card number, or mobile subscriber identification number) which is translated by SCCP into a destination point code and subsystem number. A subsystem number uniquely identifies an application at the destination signaling point. SCCP is used as the transport layer for TCAP-based services.
Signaling Protocol
A protocol that enables an asynchronous transfer mode (ATM) system to transfer service-related information between the user and the network, and among network elements. Signaling takes place between the user and the network over the user-to-network interface (UNI). Signaling takes place between network elements over the network-to-network interface (NNI). The signaling protocols in UNI 3.0/3.1 support four ATM service classes—Constant Bit Rate (CBR), Variable Bit Rate-Real Time (VBR-RT), Variable Bit Rate Non-Real Time (VBR-NRT), and Available Bit Rate/Unspecified Bit Rate (ABR/UBR).
Signaling System 7 (SS7)
See Common Channel Signaling Version 7 (CCS 7).
Signaling Types
The sending device and the receiving device must send signals in order to synchronize their clocks and determine where one block of data ends and the next begins. Services use signaling types to maintain synchronization and transfer data effectively. Signals are either analog or digital. In-band signaling is used by POTS, where all of the information about the beginning and end of a call is carried on a single line. ISDN BRI uses two B channels to carry data and a D channel to carry signaling data.
Silicon
A dark gray, hard crystalline solid. Next to oxygen, the second most abundant element on earth. It is the basic material for chips and other semiconductor devices. See for more info.
Simple Internet Protocol
Simple Internet Protocol.
Simple Mail Transfer Protocol (SMTP)
In the TCP/IP protocol suite, SMTP is an application-layer protocol that uses the TCP transport-layer protocol to send and receive electronic mail.
Single mode fiber
A fiber having a small core diameter and in which only one mode will propagate at the wavelengths of interest.
Single-mode Fiber
A fiber having a small core diameter and in which only one mode will propagate at the wavelengths of interest.
Smart Card
A credit card with a built-in microprocessor and memory used for identification or financial transactions. When inserted into a card reader, it transfers data to and from a central computer.
Smart Jack
A common name for RJ48X.
Socket
A TCP/IP interface that facilitates a two-way link between systems, enabling applications to run over a connectionless network. A socket is defined by two addresses: the IP address of the host computer, and the port address of the application or process running on the host.
Software Compression
Software compression removes waste and redundancy in a data file in order to save space and enable faster throughput. The results of compression depend on the content of each file being compressed: some contain a lot of waste, some contain almost none.
Source Address
In a frame, packet, or message sent over a bridged or routed connection, the IP, IPX, AppleTalk, or hardware address of the device that sent the transmission. Compare with destination address.
Source Laser
A laser used as a light source in an externally modulated system
Source Port
The port from which a transmission originates, such as a User Datagram Protocol (UDP) port on an authentication server, or a simple mail transfer protocol (SMTP) port on a mail server. Compare with destination port.
Source Quench
A congestion control technique in which a machine experiencing congestion sends a message back to the source of the packets causing the congestion requesting that the source stop transmitting. In Internet gateways use ICMP source quench to stop and reduce the transmission of IP datagrams.
Source Route
A route that is determined by the source. In the Internet source routing is implemented using the option field of an IP datagram.
Spectrum
Electromagnetic Spectrum: includes all frequencies from 10 hertz, just below human hearing, to 1025 hertz, cosmic ray range. Radio spectrum: the region of the spectrum including frequencies between 3 kilohertz and 300 gigahertz.
Spread Spectrum Technology
This technique sends a message as a series of computer codes. However, since the signal is stretched out over a broad frequency band, the receiver only needs to receive a part of the transmitted signal to reconstruct the original message.
Stacks
A stack is group of MAX units with a single stack name, acting as a single, logical unit. Stacks allow incoming (only) MP or MP+ calls to span multiple MAX units on a single LAN. There is no master unit in a stack. A MAX can become a member of a stack or leave a stack at any time, and there is no requirement to join a stack.
Standards
The interfaces by which computer and communications systems operate; typically determined by international standards-setting bodies.
Star Topology
A network configuration in which the nodes are connected to a single central hub rather than to each other. See ring topology.
Start Bit
In asynchronous transmission, a bit that indicates the beginning of a new character. It is always 0 (zero).
Stateful Inspection
Tracks the transaction in order to verify that the destination of an inbound packet matches the source of a previous outbound request. Can generally examine multiple layers of the protocol stack, including the data, if required, so blocking can be made at any layer or depth.
Statistical Time Division Multiplexing
A method of Time Division Multiplexing in which the time slots on a shared medium, like a switch, are allocated to complete the connection between two paths.
Stimulated Brillouin Scattering
A nonlinear phenomenon that can cause distortion of an optical signal in a fiber.
Straight-Through Cable
A cable with wires that have terminating ends with the same wire assignments.
Structured Cabling System (SCS)
A set of cabling and connecting products that supports the voice, data, and/or video networks inside a building or campus of building. SYSTIMAX® SCS is Lucent Technologies' Structured Cabling System offer.
Subscriber Network Interface (SNI)
The SNI is the interface between the network supporting switched multimegabit data service (SMDS) and the subscriber-owned equipment. The service provider assigns SMDS addresses that identify the SNI from which the data unit was sent and/or the SNI for which it was destined. Each address can be an individual address or a group address.
Substrate
A base on which layers are formed on a wafer. See for more info.
Summarization
In data networking. the process of combining routing information from one routing protocol into another for advertisement.
Superuser
In UNIX, a user with special privileges (also known as root). Only the superuser, for example, can change the password file and edit major system administration files in the /etc directory.
Supervisory Frame
On an X.25 network, a frame that can request and suspend transmission, report on link status, and acknowledge I-frames.
Switch
A device that connects the calling party to the answering party.
Switched 1536
A dial-up network-based service providing a data channel operating at a rate of 1536 kbit/s.
Switched 384
A dial-up network-based service providing a data channel operating at a rate of 384 kbit/s.
Switched 56
A dial-up network-based service providing a data channel operating at a rate of 56 kbit/s. Also a type of network access line, used to provide access to switched 56 network services.
Switched 64
A dial-up network-based service providing a data channel operating at a rate of 64 kbit/s.
Switched Access Remote Test System (SARTS)
The operations systems that provides a remote, centralized way to test special services circuits in a communications network from end to end.
Switched Channel
A channel that provides a temporary connection for the exchange of data. The channel is cleared when the call ends.
Switched Digital Services Applications Forum (SDSAF)
A consortium of equipment vendors, service vendors, and users, with the goal of advancing the state of switched digital services.
Switched Line
A line consisting of channels in use only for the duration of the connection.
Switched Virtual Circuit
A virtual circuit established on demand by an end user employing signaling.
Switched-56 Line
A line that provides a single 56-Kbps data channel with inband signaling.
Symbolic Name
A name used in place of an IP address.A symbolic name consists of a user name and a domain name in the format user name@domain name. The user name corresponds to the host number in the IP address. The domain name corresponds to the network number in the IP address. A symbolic name might be steve@crocker.com or joanne@cal.edu.
Symmetric Digital Subscriber Line (SDSL)
A new technology that allows more data to be sent over existing copper telephone lines (POTS). SDSL supports rates up to 3 Mbps.
Synchronization
In serial data transmission, a method of ensuring that the receiving end can recognize characters in the order in which the transmitting end sent them, and can know where one character ends and the next begins. Without synchronization, the receiving end would perceive data simply as a series of binary digits with no relation to one another. Synchronous communication relies on a clocking mechanism to synchronize the signals between the sending and receiving machines.
Synchronous Data Link Control (SDLC)
A predecessor of HDLC defined by IBM Corporation and used in their SNA products.
Synchronous Digital Hierarchy
A broadband transmission standard in which uniform modular transmission containers and/or frames contain both message elements and overhead information to provide smooth, reliable networking efficiency.
Synchronous Optical Network (SONET)
SONET is a Bellcore specification currently used in worldwide public data networks (PDNs). It defines a synchronous optical network-based user-network interface (UNI), either public or private, operating at speeds from 51 Mbps to 2 Gbps over single-mode optical fiber.
Synchronous Transmission
A transmission mode in which the data moves in large blocks, called messages or frames. Both the sending device and the receiving device must maintain synchronization in order to determine where one block of data ends and the next begins. Synchronization can take one of these forms:
Sysop
System operator. A person responsible for the day-to-day operation of a computer system or network resource - for example, server, LAN, bulletin board system, online service, or special interest group.
System on a Chip
In microelectronics, the placement of a number of different key functions on the same chip. Today, a system on a chip means integrating the full system, including analog components, logic, digital signal processors, microprocessor cores, and memory. See
System-Level Integration
In semiconductor design and fabrication, packing higher and higher numbers of increasingly complex devices into an integrated circuit. The end result is the system on a chip.
System-based Routing
A form of IP routing in which the entire unit has a single IP address. For systems that have a single backbone connection, system-based routing is the simplest way to configure the Lucent unit.
single thread
A connection between transmission and receive device that operates without the benefit of redundancy.
n. See S/T interface.
S-interface
adj. See S/T interface.
S/T Interface, Adj.
Specifies an ISDN communications device that connects to an external network terminator (NT1).
S/T Interface, N.
The electrical interface between a network terminator (NT1) device and one or more ISDN communications devices that do not contain their own NT1s.
SA Broadband
A family of products that enables a service provider to implement asynchronous transfer mode (ATM) services such as data, voice, and video.
SAM
Secure Access Manager. Secure Access Manager gives network administrators granular control over the security functions of the entire network directly from the central site. Through this Windows-based application, network administrators can configure the Secure Access Firewall(s) off line and download the configuration to remote locations. The menu-driven program enables network administrators to easily configure the firewall on the network.
SAP
Service Access Point
SAP Filters
See NetWare call filters.
SBS
Stimulated Brillouin Scattering
SC/APC
Subscription Channel / Angled Polished Connector
SDH
Synchronous Digital Hierarchy: A standard that defines transmission rates for global high-speed multiplexing.
SDRP
Source Demand Routing Protocol
SDSAF
See Switched Digital Services Applications Forum.
SEP
Sequential Exchange Protocol
SIP
Simple Internet Protocol
SLIP
Serial Line Internet Protocol. The protocol that was made obsolete by Point-to-Point Protocol, for point-to-point serial connections using TCP/IP.
SLIP (Serial Line IP)
A protocol that enables your computer to send and receive IP packets over a serial link.
SMDR
Station Management Detail Recording. The ability of network access equipment to output call statistics and performance information for tabulation and analysis.
SMDS
Switched Multimegabit Data Service. A packet-based network service allowing the creation of high-speed data networks (up to 45 Mbit/s). Now in the testing and initial implementation phases.
SMTP
Simple Mail Transfer Protocol. A protocol for exchanging email messages between servers across a network. SMTP is the principle protocol for sending email over the Internet.
SNAP
SubNetwork Access Protocol
SNMP
Simple Network Management Protocol. A standard way for computers to share networking information. In SNMP, two types of communicating devices exist: agents and managers. An agent provides networking information to a manager application running on another computer. The agents and managers share a database of information, called the Management Information Base (MIB). An agent can use a message called a traps-PDU to send unsolicited information to the manager.
SONET
Synchronous Optical Network. SONET is a Bellcore specification currently used in worldwide public data networks (PDNs). It defines a synchronous optical network-based user-network interface (UNI), either public or private, operating at speeds from 51 Mbps
SPID
Service Profile Identifier. Your ISDN service provider (telephone company) uses this number at the Central Office switch to identify services on your ISDN line. This number is derived from a telephone number. See also Central Office and ISDN.
SQL
Structured query language. A standard interactive and programming language for requesting information from and updating databases.
SS7
Signaling System 7: a signaling method-separate from voice or data channel-that lets Intelligent Network elements exchange information among themselves.
SSL
Secure Sockets Layer. A program layer of network, and also a protocol that enable encrypted and authenticated communications across the Internet. Many websites use SSL protocol to obtain confidential user information.
SVC
Switched Virtual Circuit. A path over a packet-switched network that appears to be a dedicated circuit, but in fact the connection only stays up as long as needed, and then ends. (Also see PVC.)
SW56
See Switched 56.
SWIPE
IP with Encryption
Scalable
Able to be changed in size or configuration to suit changing conditions. For example, a scalable network can be expanded from a few nodes to thousands of nodes.
Screen Pop
In Computer Technology Integration, the appearance of database information about a caller, while the phone is ringing, on the call recipient's computer screen.
Secure Access Firewalls
Secure Access Firewall is a software option for Ascend units that offers a fully integrated firewall security for remote networking. It uses state-of-the-art dynamic firewall technology to deliver a comprehensive security solution for the corporate LAN, remote office LAN and telecommuter's LAN that stops intruders from breaking and entering into networks. Securing the perimeter of the local network where it meets the Internet sets the stage for using the Internet for Intranet applications.
Secure ID
A proprietary brand of security card (about the size of a credit card) that generates a code based on the user’s ID, password, and information in the card. When the user attempts to log on to a secure network, a code is requested that must have been generated within the previous 60 seconds. The server interprets the code, and if it is found to be genuine, the user is granted access.
SecureConnect
The Lucent suite of security features, which provide a complete solution for establishing secure sessions across the Internet. The SecureConnect features work with the Lucent MAX and Pipeline products. SecureConnect Firewall is an ICSA-certified, dynamic firewall technology. SecureConnect Firewall + VPN is an integrated firewall and encryption feature that enables users to conduct authenticated and confidential sessions over the public Internet. SecureConnect Client is PC client software that gives remote and mobile users the same confidential and secure connections that network users enjoy via SecureConnect Pipeline and MAX products. SecureConnect Server is a Web-accessible, RADIUS-based user authentication system.
SecureConnect Firewalls
A software option for Lucent units that offers a fully integrated firewall security for remote networking. It uses state-of-the-art dynamic firewall technology to deliver a comprehensive security solution for the corporate LAN, remote office LAN and telecommuter’s LAN that stops intruders from breaking and entering into networks. Securing the perimeter of the local network where it meets the Internet sets the stage for using the Internet for Intranet applications.
SecureConnect Manager
SecureConnect Manager gives network administrators granular control over the security functions of the entire network directly from the central site. Through this Windows based application, network administrators can configure the SecureConnect Firewall(s) off line and download the configuration to remote locations. The menu-driven program enables network administrators to easily configure the firewall on the network.
Security Cards
See Secure ID.
Selective Acknowledgment (SACK)
An acknowledgement mechanism used with the sliding window protocols that allows the receiver to acknowledge packets received out of order but within the current sliding window.
Semiconductor
A crystalline solid that behaves somewhere between a conductor (like iron) and an insulator (like glass). Semiconductors are the raw materials used in active electronic and optical devices.
Sensitivity
The input level required for a device to provide a predetermined output.
Serial Communication
Communication through the serial port of your computer. For Windows 3.1, the maximum speed of the serial port is 19,200. For Windows 95, the COM port limit on the settings drop-down list is 921,600. These limitations are subject to change as development of a faster serial bus design is implemented.
Serial Connection
A link between the serial ports of two devices.
Serial Host
A device, such as a videoconferencing codec, that is connected to a serial host port communicating over a point-to-point link. To a serial host, the MAX appears to be a cable or DCE (Data Communications Equipment).
Serial Host Port
The V.35, RS-499, or X.21 port on the MAX.
Serial Host Port Module
A module on the MAX that connects to a serial host through its serial host port.
Serial Line IP
A protocol that enables your computer to send and receive IP packets over a serial link.
Serial Number Exchange Protocol (SNEP)
Packets that are used to ensure that one copy of NetWare has not been loaded onto more than one NetWare Server. SNEP packets, by default are NOT filtered and therefore will cause a link to be dialed in a routed IPX environment. SNEP can be call filtered using the same offset rules as an 802.2 or 802.3 frame type, wit its designated socket number. It uses a destination socket of 0457.
Serial Transmission
A form of data transmission in which only one line carries all eight bits of a byte. In serial transmission, one bit follows another (as opposed to parallel transmission, in which the bits travel simultaneously, each on a different wire). Serial transmission can be either synchronous or asynchronous. Synchronous communication requires additional lines for transmitting handshake or timing signals. In asynchronous communication, the data itself contains synchronization information, so neither handshake nor clock signals are necessary.
Serial port
A bidirectional channel through which data flows one bit as a time.
Server
A server is a shared computer on the local area network that can be as simple as a regular PC set aside to handle print requests to a single printer. Or, more commonly, it is the fastest and brawniest PC around. It may be used as a repository and a distributor of oodles of data. It may also be the gatekeeper controlling access to voice mail, electronic mail, and facsimile services.
Service Control Point
An Intelligent Network element. A programmable intelligent database server that contains service intelligence and stores call control and routing instructions for delivery of services.
Service Creation Environment (SCE)
A leading service development system that allows service providers, Lucent Technologies, and selected third-party vendors to create or customize innovative services. Provide the power to develop, test, and implement, via Lucent Technologies Intelligent Network products, breakthrough communication and information services.
Service Management
The ability to create and control data services, enabling fast and cost-effective deployment and ongoing management. For service providers, service management means the ability to create a variety of services targeted for varied enterprise market segments with appropriate traffic management plans and price models. For enterprises, service management means new, public data services targeted and priced for business needs that the enterprise can measure directly with access to network information.
Service Management System
The administration, management, and provisioning server that handles the complexities of delivering services throughout the intelligent network.
Service Node
An element in an advanced public network ing architecture at which service requests, including service switching, are processed.
Service Node Service Control Point (SN-SCP)
A component of the GlobeView[R]-2000 Service Node that provides control functions for the Interface and Services Stage (ISS) and the ATM Interconnect Shelf.
Service Switching Point
In the intelligent network, the node normally associated with the serving office. It recognizes calls requiring special handling and sends them either to the Service Control Point, Service Node.
Session
The state a connection reaches when bothparties can communicate with each other.
Shielded Twisted Pair Cable
STP cable consists of two wires twisted two or more times per inch in order to help cancel out noise. The entire cable has a protective covering. STP cable is typically used in ARCnet and token ring networks.
Short haul
According to some definitions, a distance between several hundred yards and 20 miles.
Shorter Radio Wave
In wireless communications, this wave enables a radio signal to travel through small openings and navigate around physical obstructions that can cause interference.
Shortest Path Routing
A routing algorithm that calculates the path distance to all network destinations. A cost assigned to each link determines the shortest path.
Signal Transfer Point
A packet switching device in the CCS 7 network. See Common Channel Signaling Version 7 (CCS 7).
Signaling ATM Adaptation Layer (SAAL)
The SAAL is a mechanism for ensuring that signaling messages are reliably transported between network peers. It resides between the Asynchronous Transfer Mode (ATM) Layer and Q.2931 in the user’s equipment. The purpose of the SAAL is to provide reliable transport of Q.2931 messages between peer Q.2931 entities, such as an ATM switch and host, over the ATM Layer. The SAAL is subdivided into the Common Part (CP) and the Service-Specific Part (SSP).
Signaling Connection Control Part (SCCP)
Provides connectionless and connection-oriented network services and global title translation (GTT) capabilities above MTP Level 3. A global title is an address (e.g., a dialed 800 number, calling card number, or mobile subscriber identification number) which is translated by SCCP into a destination point code and subsystem number. A subsystem number uniquely identifies an application at the destination signaling point. SCCP is used as the transport layer for TCAP-based services.
Signaling Protocol
A protocol that enables an asynchronous transfer mode (ATM) system to transfer service-related information between the user and the network, and among network elements. Signaling takes place between the user and the network over the user-to-network interface (UNI). Signaling takes place between network elements over the network-to-network interface (NNI). The signaling protocols in UNI 3.0/3.1 support four ATM service classes—Constant Bit Rate (CBR), Variable Bit Rate-Real Time (VBR-RT), Variable Bit Rate Non-Real Time (VBR-NRT), and Available Bit Rate/Unspecified Bit Rate (ABR/UBR).
Signaling System 7 (SS7)
See Common Channel Signaling Version 7 (CCS 7).
Signaling Types
The sending device and the receiving device must send signals in order to synchronize their clocks and determine where one block of data ends and the next begins. Services use signaling types to maintain synchronization and transfer data effectively. Signals are either analog or digital. In-band signaling is used by POTS, where all of the information about the beginning and end of a call is carried on a single line. ISDN BRI uses two B channels to carry data and a D channel to carry signaling data.
Silicon
A dark gray, hard crystalline solid. Next to oxygen, the second most abundant element on earth. It is the basic material for chips and other semiconductor devices. See for more info.
Simple Internet Protocol
Simple Internet Protocol.
Simple Mail Transfer Protocol (SMTP)
In the TCP/IP protocol suite, SMTP is an application-layer protocol that uses the TCP transport-layer protocol to send and receive electronic mail.
Single mode fiber
A fiber having a small core diameter and in which only one mode will propagate at the wavelengths of interest.
Single-mode Fiber
A fiber having a small core diameter and in which only one mode will propagate at the wavelengths of interest.
Smart Card
A credit card with a built-in microprocessor and memory used for identification or financial transactions. When inserted into a card reader, it transfers data to and from a central computer.
Smart Jack
A common name for RJ48X.
Socket
A TCP/IP interface that facilitates a two-way link between systems, enabling applications to run over a connectionless network. A socket is defined by two addresses: the IP address of the host computer, and the port address of the application or process running on the host.
Software Compression
Software compression removes waste and redundancy in a data file in order to save space and enable faster throughput. The results of compression depend on the content of each file being compressed: some contain a lot of waste, some contain almost none.
Source Address
In a frame, packet, or message sent over a bridged or routed connection, the IP, IPX, AppleTalk, or hardware address of the device that sent the transmission. Compare with destination address.
Source Laser
A laser used as a light source in an externally modulated system
Source Port
The port from which a transmission originates, such as a User Datagram Protocol (UDP) port on an authentication server, or a simple mail transfer protocol (SMTP) port on a mail server. Compare with destination port.
Source Quench
A congestion control technique in which a machine experiencing congestion sends a message back to the source of the packets causing the congestion requesting that the source stop transmitting. In Internet gateways use ICMP source quench to stop and reduce the transmission of IP datagrams.
Source Route
A route that is determined by the source. In the Internet source routing is implemented using the option field of an IP datagram.
Spectrum
Electromagnetic Spectrum: includes all frequencies from 10 hertz, just below human hearing, to 1025 hertz, cosmic ray range. Radio spectrum: the region of the spectrum including frequencies between 3 kilohertz and 300 gigahertz.
Spread Spectrum Technology
This technique sends a message as a series of computer codes. However, since the signal is stretched out over a broad frequency band, the receiver only needs to receive a part of the transmitted signal to reconstruct the original message.
Stacks
A stack is group of MAX units with a single stack name, acting as a single, logical unit. Stacks allow incoming (only) MP or MP+ calls to span multiple MAX units on a single LAN. There is no master unit in a stack. A MAX can become a member of a stack or leave a stack at any time, and there is no requirement to join a stack.
Standards
The interfaces by which computer and communications systems operate; typically determined by international standards-setting bodies.
Star Topology
A network configuration in which the nodes are connected to a single central hub rather than to each other. See ring topology.
Start Bit
In asynchronous transmission, a bit that indicates the beginning of a new character. It is always 0 (zero).
Stateful Inspection
Tracks the transaction in order to verify that the destination of an inbound packet matches the source of a previous outbound request. Can generally examine multiple layers of the protocol stack, including the data, if required, so blocking can be made at any layer or depth.
Statistical Time Division Multiplexing
A method of Time Division Multiplexing in which the time slots on a shared medium, like a switch, are allocated to complete the connection between two paths.
Stimulated Brillouin Scattering
A nonlinear phenomenon that can cause distortion of an optical signal in a fiber.
Straight-Through Cable
A cable with wires that have terminating ends with the same wire assignments.
Structured Cabling System (SCS)
A set of cabling and connecting products that supports the voice, data, and/or video networks inside a building or campus of building. SYSTIMAX® SCS is Lucent Technologies' Structured Cabling System offer.
Subscriber Network Interface (SNI)
The SNI is the interface between the network supporting switched multimegabit data service (SMDS) and the subscriber-owned equipment. The service provider assigns SMDS addresses that identify the SNI from which the data unit was sent and/or the SNI for which it was destined. Each address can be an individual address or a group address.
Substrate
A base on which layers are formed on a wafer. See for more info.
Summarization
In data networking. the process of combining routing information from one routing protocol into another for advertisement.
Superuser
In UNIX, a user with special privileges (also known as root). Only the superuser, for example, can change the password file and edit major system administration files in the /etc directory.
Supervisory Frame
On an X.25 network, a frame that can request and suspend transmission, report on link status, and acknowledge I-frames.
Switch
A device that connects the calling party to the answering party.
Switched 1536
A dial-up network-based service providing a data channel operating at a rate of 1536 kbit/s.
Switched 384
A dial-up network-based service providing a data channel operating at a rate of 384 kbit/s.
Switched 56
A dial-up network-based service providing a data channel operating at a rate of 56 kbit/s. Also a type of network access line, used to provide access to switched 56 network services.
Switched 64
A dial-up network-based service providing a data channel operating at a rate of 64 kbit/s.
Switched Access Remote Test System (SARTS)
The operations systems that provides a remote, centralized way to test special services circuits in a communications network from end to end.
Switched Channel
A channel that provides a temporary connection for the exchange of data. The channel is cleared when the call ends.
Switched Digital Services Applications Forum (SDSAF)
A consortium of equipment vendors, service vendors, and users, with the goal of advancing the state of switched digital services.
Switched Line
A line consisting of channels in use only for the duration of the connection.
Switched Virtual Circuit
A virtual circuit established on demand by an end user employing signaling.
Switched-56 Line
A line that provides a single 56-Kbps data channel with inband signaling.
Symbolic Name
A name used in place of an IP address.A symbolic name consists of a user name and a domain name in the format user name@domain name. The user name corresponds to the host number in the IP address. The domain name corresponds to the network number in the IP address. A symbolic name might be steve@crocker.com or joanne@cal.edu.
Symmetric Digital Subscriber Line (SDSL)
A new technology that allows more data to be sent over existing copper telephone lines (POTS). SDSL supports rates up to 3 Mbps.
Synchronization
In serial data transmission, a method of ensuring that the receiving end can recognize characters in the order in which the transmitting end sent them, and can know where one character ends and the next begins. Without synchronization, the receiving end would perceive data simply as a series of binary digits with no relation to one another. Synchronous communication relies on a clocking mechanism to synchronize the signals between the sending and receiving machines.
Synchronous Data Link Control (SDLC)
A predecessor of HDLC defined by IBM Corporation and used in their SNA products.
Synchronous Digital Hierarchy
A broadband transmission standard in which uniform modular transmission containers and/or frames contain both message elements and overhead information to provide smooth, reliable networking efficiency.
Synchronous Optical Network (SONET)
SONET is a Bellcore specification currently used in worldwide public data networks (PDNs). It defines a synchronous optical network-based user-network interface (UNI), either public or private, operating at speeds from 51 Mbps to 2 Gbps over single-mode optical fiber.
Synchronous Transmission
A transmission mode in which the data moves in large blocks, called messages or frames. Both the sending device and the receiving device must maintain synchronization in order to determine where one block of data ends and the next begins. Synchronization can take one of these forms:
Sysop
System operator. A person responsible for the day-to-day operation of a computer system or network resource - for example, server, LAN, bulletin board system, online service, or special interest group.
System on a Chip
In microelectronics, the placement of a number of different key functions on the same chip. Today, a system on a chip means integrating the full system, including analog components, logic, digital signal processors, microprocessor cores, and memory. See
System-Level Integration
In semiconductor design and fabrication, packing higher and higher numbers of increasingly complex devices into an integrated circuit. The end result is the system on a chip.
System-based Routing
A form of IP routing in which the entire unit has a single IP address. For systems that have a single backbone connection, system-based routing is the simplest way to configure the Lucent unit.
single thread
A connection between transmission and receive device that operates without the benefit of redundancy.
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