Glossary 81
Glossary
SIP
Session Initiation Protocol for voice traffic.
S-MTA
A standalone media terminal adapter converts analog voice signals to and from a standard
telephone to digital data that can be transmitted through a broadband connection over
the Internet.
SSH
secure shell
stateful
inspection
A type of firewall that tracks each connection traversing all firewall interfaces to ensure validity. In
addition to examining the source and destination in the packet header based on static rules, a
stateful inspection firewall:
•
Examines packet headers on context established by previous packets that traversed the firewall
•
Monitors the connection state and saves it in a table
•
Closes ports until a connection to a specific port is requested
•
May examine the packet contents up through the application layer to determine more than just
the source and destination
A stateful-inspection firewall is more advanced than a static filter firewall.
static filter
A type of firewall that examines the source and destination in the packet header based on
administrator-defined rules
only
.
static IP address
An IP address that is permanently assigned to a host. Normally, a static IP address must be
assigned manually. The opposite of dynamic IP address.
subnet mask
A bit mask that is logically ANDed with the destination IP address of a packet to determine the
network address. A router routes packets using the network address.
subnetwork
A part of a network; commonly abbreviated “subnet.” When subnetting is used, the host portion
of the IP address is divided into a subnet and host number. Hosts and routers use the subnet
mask to identify the bits used for the network and subnet number.
TCP
Transmission Control Protocol provides reliable transport over the network for data transmitted
using IP. It defines rules and procedures for data exchange.
