GL-29
Cisco Router and Security Device Manager Version 2.2 User’s Guide
OL-4015-08
Glossary
SHA-1 Secure Hashing Algorithm 1. Algorithm that takes a message of less than 264
bits in length and produces a 160-bit message digest. The large messa ge digest
provides security against brute-force collision and inversion attacks. SHA-1
[NIS94c] is a revision to SHA that was published in 1994.
shared key The secret key that all users share in a symmetric key-based communication
session.
shared secret A crytographic key.
signature See digital signature.
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.
spoke In a DMVPN network, a spoke router is a logical end point in the network, and
has a point-to-point IPSec connection with a DMVPN hub router.