Glossary
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Cisco Router and Security Device Manager 2.5 User’s Guide
OL-4015-12
signature A data element in IOS IPS that detects a specific pattern of misuse on the
network.
signature engine A signature engine is a component of Cisco IOS IPS designed to support m any
signatures in a certain category. An engine is composed of a parser and an
inspector. Each engine has a set of legal parameters which have allowable ranges
or sets of values.
signing certificate Used to associate your digital signature with your messages or d ocuments, and
to ensure that your messages or files are conveyed without changes.
SIP Session Initiation Protocol. Enables call handling sessions, particularly
two-party audio conferences, or “calls.” SIP works with Session Description
Protocol (SDP) for call signaling. SDP specifies the ports for the media stream.
Using SIP, the router can support any SIP Voice over IP (VoIP) gateways and
VoIP proxy servers.
site-to-site VPN Typically, a site-to-site VPN is one that connects two networks or subneworks
and that meets several other specific criteria, including the use of static IP
addresses on both sides of the tunnel, the absence of VPN client software on user
end-stations, and the absence of a central VPN hub (as would exist in
hub-and-spoke VPN configurations). Site-to-site VPNs are not intende d to
replace dial-in access by remote or traveling users.
SMTP Simple Mail Transfer Protocol. Internet protocol providing e-mail services.
SNMP Simple Network Management Protocol. Network management protocol used
almost exclusively in TCP/IP networks. SNMP provides a means to monitor and
control network devices, and to manage configurations, statistics collection,
performance, and security.
SPD Selective Packed Discard. SPD provides priority to routing protocol packets and
other important traffic control Layer 2 keepalives during periods of queue
congestion.
Split DNS Split DNS enables Cisco routers to answer DNS queries using the internal
hostname cache specified by a selected virtual DNS name server. Queries that
cannot be answered by the information in the hostname cache, are redirected to
specified back-end DNS name servers.