Glossary P
Centillion 1200N ATM Switch User Manual B-57
NTP 297-8103-903
PHY
OSI Physical Layer: The physical layer provides for transmission of cells over a
physical medium connecting two ATM devices. This physical layer is comprised
of two sublayers: the PMD Physical Medium Dependent sublayer, and the TC
Transmission Convergence sublayer. Refer PMD and TC.
Physical Layer (PHY) Connection
An association established by the PHY between two or more A TM ent ities. A PHY
connection consists of the concatenation of PHY links in order to provide an end-
to-end transfer capability to PHY SAPs.
Physical Link
A real link which attaches two switching systems.
PICS
Protocol Implementation Conformance Statement: A statement made by the
supplier of an implementation or system stating which capabilities have been
implemented for a given protocol.
PID
Protocol Identification. Refer to OUI.
PIXIT
Protocol Implementation eXtra Information for Testing: A statement made by a
supplier or implementer of an IUT which contains information about the IUT and
its testing environment which will enable a test laboratory to run an appropriate test
suite against the IUT.
Plastic Fiber Optics
An optical fiber where the core tran smission media is plastic in contra st to glass or
silica cores. Proposed plastic fibers generally have larger att enuation and dispersio n
than glass fiber but may have applications where the distance is limited. Plastic
systems may also offer lower cost connectors that may be installed with simple
tools and a limited amount of training.
PLCP
Physical Layer Convergence Protocol: The PLCP is defined by the IEEE 802.6. It
is used for DS3 transmission of ATM. ATM cells are encapsulated in a
125microsecond frame defined by the PLCP which is defined inside the DS3 M-
frame.