User's Manual

260 BreezeMAX Modular Base Station System Manual
Glossary
SIP Session Initiation Protocol. An application-layer control IETF
protocol that can establish, modify, and terminate multimedia
sessions such as Internet telephony calls (VoIP). 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.
SLA Service Level Agreement. A contract between a service provider and
the end user, which stipulates and commits the service provider to a
required level of service. An SLA relates to issues such as specified
level of service, support options, enforcement or penalty provisions
for services not provided, a guaranteed level of system performance
as relates to downtime or uptime, a specified level of customer
support and what software or hardware will be provided and for
what fee.
SME Small and Medium-sized Enterprises. SMEs are small-scale
entrepreneurial private enterprises: they are usually defined as
having less than 250 employees, but most have far fewer.
SNAP Sub Network Access Protocol
SNMP Simple Network Management Protocol. A network management
protocol that provides a means to monitor and control network
devices, and to manage configurations, statistics collection,
performance, and security. SNMP works by sending messages,
called protocol data units (PDUs), to different parts of a network.
SNMP-compliant devices, called agents, store data about themselves
in Management Information Bases (MIBs) and return this data to the
SNMP requesters.
SNR Signal to Noise Ratio. The ratio of the amplitude of a desired analog
or digital data signal to the amplitude of noise in a transmission
channel at a specific point in time. SNR is typically expressed
logarithmically in decibels (dB). SNR measures the quality of a
transmission channel or a signal over a network channel. The
greater the ratio, the easier it is to identify and subsequently isolate
and eliminate the effects of noise. SNR also is abbreviated as S/N.