RA - Rectifier Alarm

RAL - Receipt Acknowledgement Letter (used for Form 471)

RAM - Random Access Memory

RARP - Reverse Address Resoultion Protocol

RBOC - Regional Bell Operating Company

RCA - Radio Corporation of America

RDI - Remote Defect Indicator (UNI Fault Management)

RED - Random Early Discard

RF - Radio Frequency

RFA - Rectifier Failure Alarm

RFC - Request For Comment

RFFG - Remote Forwarder Functional Group

RFI - Request For Information

RFP - Request For Proposal

RFQ - Request For Quotation

RG - Ring Ground

RIF - Rate Increase Factor

RGB - Red-Green-Blue

RIP - Routing Information Protocol

RM - Resource Management

RMON - Remote Monitoring

RNL - Receipt Notification Letter (used for Form 470)

ROLC - Routing Over Large Clouds

ROM - Read-Only Memory

RPQ - Request for Price Quotation

RSFG - Route Server Functional Group (ATM Forum, MPOA SWG)

RSVP - Reservation Protocol

SA - Source Address

SAA - Systems Applications Architecture

SAAL - Signaling ATM Adaptation Layer

SAP - Service Access Point

SAR - Segmentation and Reassembly

SAS - Single Attached Station

SC - Stick and Click

SCP - System control Processor

SCSI - Small Computer Systems Interface

SCR - Silicon-Controlled Rectifier

SCR - Sustainable Cell Rate

SCT - Same Clock Timing

SDH - Synchronous Digital Hierarchy

SDLC - Synchronous Data Link Control

SDU - Service Data Unit

SEAL - Simple and Efficient Adaptation Layer

SECAM - Sequential with Memory

SECB - Severly Errored Cell Block

SEL - Selector

SES - Severely Errored Seconds

SF - Single Frequency

SF - Switch Fabric

SFD - Start of Frame Delimiter

SI - Status Indicator

SIMM - Single In-line Memory Module

SIR - Sustained Information Rate

SLC - School and Libraries Corporation (former name)

SLD - Schools and Libraries Division of USAC; created after 1999 merger

SLIP - Serial Line IP

SM - Single Mode

S.M.A.R.T. ® - Sophisticated Monitoring And Reporting Teleview

SMDS - Switched Multimegabit Data Service

SMF - Single Mode Fiber

SMS - Selective Multicast Service

SMTP - Simple Mail transfer Protocol

SNA - Systems Network Architecture

SNAP - Sub-Network (Area Protocol) Attachment Point

SNDCF - Sub-Network Dependent Convergence Function (ATM Forum, MPOA SWG)

SNMP - Simple Network Management Protocol

SONET - Synchronous Optical Network

SP - Service Provider (vendor)

SPAC Form Service Provider Annual Certification Form (Form 473)

SPANS - Simple Protocol for ATM Network Signaling

SPI Form (also Service Provider Invoiceknown as SPIF) Form (Form 474)

SPIN - Service Provider Identification Number, provided when you register for the Program by filing a Form 498

SPVC - Soft Permanent Virtual Connection

SRB - Source Routing Bridging

SRTS - Synchronous Residual Time Stamp

SS - Switching System

SS7 - Signaling System #7

SSCF - Service Specific Coordinate Function

SSCS - Service Specific Convergence Sublayer

SSCOP - Service Specific Connection Oriented Protocol

ST - Stick and Turn

STDM - Statistical Time Division Multiplexing

STE - Section Terminating Equipment (SONET)

STM - Synchronous Transport Module

STP - Shielded Twisted Pair

STS-n - Synchronous Transport Signal-n

SVA - Signature componant of AVA/ATV

SVC - Switched Virtual Circuit

SVCC - Switched Virtual Channel Connection

SVPC - Switched Virtual Path Connection