Appendix : Glossary 137
RCF Registration Confirm—This is a call flow message.
RISC Reduced Instruction Set Computer— Central processing unit architecture that
greatly reduces processing time by having fewer, simpler instructions programmed
into ROM, but allowing for complex processing by combining these simple
instructions; primarily used in workstations.
RFI Radio Frequency Interface—An interface of a programmable switch matrix
between the RF test instruments of a CASS RF or CNI configuration to a series of
front panel bulkhead connectors.
RRAS Routing and Remote Access Service—Microsoft Windows NT’s (RRAS) Routing and
Remote Access Service is used for terminating RAS/PPP calls on a Microsoft Windows
NT system.
RRJ Registration Reject—A registration request from an H.323 Gateway to an H.323
Gatekeeper was rejected.
RRQ Registration Request—An H.323 Gateway has requested to register with a remote
H.323 Gatekeeper endpoint.
RTP Real Time Protocol—The format of the audio/voice data as it travels through VoIP.
RTS Request to Send—An RS-232 signal provided by a DTE device to a DCE device
saying "I am ready when you are”. The RTS/CTS RS-232 signals are often used for
flow control between a modem and serial port.
SCSI Small Computer System Interface—The way the peripherals communicate with
the computer’s main processor.
SDL Signaling Data Link or Software Download
SF Super Frame—Common framing type used on T1 circuits. SF consists of 12 frames
of 192 bits each, with the 193rd bit providing error checking and other functions.
SF is superseded by ESF, but is still widely used. Also called D4 framing.
SCP Service Control Points—The SCP stores customer specific information for example,
toll free numbers, and converts the inf ormation received from the incoming call
and directs the call to its destination.
SIP Session Initiation Protocol—Provides advanced telephony services across an IP
network.
SGP Signaling Gateway Platform—This is the SS7 Signaling Gateway platform. 3Com’s
SS7 signaling Gateway is an intelligent service exchange node that integrates
services between the circuit and packet networks to deliver significant cost savings
with IMTs for voice trunk access instead of ISDN PRIs.
SLAP Signaling LAN Application Protocol—SLAP is the interface between the Total
Control Chassis and the external SS7 Gateway system. It replaces the D-channel
signaling that normally exists in an ISDN PRI interface. SLAP is 3Com’s proprietary
software.
SSP Signaling Switch Point—Simply put, this is the telephone switch.