Glossary
GL-10
Cisco uBR10012 Universal Broadband Router Hardware Installation Guide
78-11450-03 Rev.B0
Optical carrier See OC.
Optical fiber See Fiber-optic cable.
P
Packet Logical grouping of information that includes a header containing control information and (usually)
user data. Packets are most often used to refer to network layer units of data. The terms datagram,
frame, message, and segment are also used to describe logical information groupings at various layers
of the OSI reference model and in various technology circles.
Packet Over SONET See POS.
Packet switching Networking method in which nodes share bandwidth with each other by sending packets.
Parallel Express
Forwarding
See PXF Network Processors.
PCMCIA Flash disk
card
A portable (credit-card size), nonvolatile storage device. PCMCIA flash disk cards use Flash
technology to store data. PCMCIA stands for Personal Computer Memory Card International
Association, which sets the standard for this technology. Also called PC card.
PEM Power entry module. A hardware module that distributes power to the chassis.
Performance
Routing Engine
See PRE.
Point of Presence See POP.
Point-to-Point
Protocol
See PPP.
POP Point of presence. A physical location where an interexchange carrier installed equipment to
interconnect with a local exchange carrier.
POS Packet Over SONET. A high-speed means of transmitting data over a SONET fiber-optic transmission
system through a direct fiber connection to a data switch or router. POS is a point-to-point dedicated
leased-line approach intended purely for high-speed data applications. POS allows a user organization
to pass data in its native format, without the addition of any significant level of overhead in the form
of signaling and control information.
POST Power-on self test. A set of hardware diagnostics that runs on a hardware device when that device is
powered on.
Power Entry Module See PEM.
Power-on self test See POST.
PPP Point-to-Point Protocol. Provides router-to-router and host-to-network connections over synchronous
and asynchronous circuits.