User Manual

Glossary
M40 Internet Router Hardware Guide
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SSH Secure shell. Software that provides a secured method of logging in to a remote network
system.
SSRAM Synchronous Static Random Access Memory.
STM Synchronous Transport Module. CCITT specification for SONET at 155.52 Mbps.
STS Synchronous Transport Signal. Synchronous Transport Signal level 1. Basic building block
signal of SONET, operating at 51.84 Mbps. Faster SONET rates are defined as STS-n, where n
is a multiple of 51.84 Mbps. See also SONET.
subnet mask Number of bits of the network address used for host portion of a Class A, Class B, or Class C
IP address.
Switch Interface Board See SIB.
sysid System identifier. Portion of the ISO nonclient peer. The sysid can be any 6 bytes that are
unique throughout a domain.
T
TCP Transmission Control Protocol. Works in conjunction with Internet Protocol (IP) to send data
over the Internet. Divides a message into packets and tracks the packets from point of origin
to destination.
ToS Type of service.
traffic engineering Process of selecting the paths chosen by data traffic in order to balance the traffic load on the
various links, routers, and switches in the network. (Definition from
http://www.ietf.org/internet-drafts/draft-ietf-mpls-framework-04.txt.) See also MPLS.
tunnel Private, secure path through an otherwise public network.
type of service See ToS.
U
unicast Operation of sending network traffic from one network node to another individual network
node.
UPS Uninterruptible power supply. Device that sits between a power supply and a router (or other
piece of equipment) the prevents undesired power-source events, such as outages and surges,
from affecting or damaging the device.
V
vapor corrosion
inhibitor
See VCI.
VCI Vapor corrosion inhibitor. Small cylinder packed with the router that prevents corrosion of
the chassis and components during shipment.
VCI Virtual circuit identifier. 16-bit field in the header of an ATM cell that indicates the particular
virtual circuit the cell takes through a virtual path. Also called a logical interface. See also VPI.
virtual circuit identifier See VCI.