Panasonic 1200N manual Pdh, Pdu, Pes, Pgi, Pgl

P Glossary

PDH

Plesiochronous Digital Hierarchy: PDH (plesiochronous means nearly synchronous), was developed to carry digitized voice over twisted pair cabling more efficiently. This evolved into the North American, European, and Japanese Digital Hierarchies where only a discrete set of fixed rates is available, namely, nxDS0 (DS0 is a 64 kbps rate) and then the next levels in the respective multiplex hierarchies.

PDU

Protocol Data Unit: A PDU is a message of a given protocol comprising payload and protocol-specific control information, typically contained in a header. PDUs pass over the protocol interfaces which exist between the layers of protocols (per OSI model).

Peer Entities

Entities within the same layer.

Peer Group Level

The number of significant bits in the peer group identifier of a particular peer group.

Peer Node

A node that is a member of the same peer group as a given node.

PES

Packetized Elementary Stream: In MPEG-2, after the media stream has been digitized and compressed, it is formatted into packets before it is multiplexed into either a Program Stream or Transport Stream.

PG

Peer Group: A set of logical nodes which are grouped for purposes of creating a routing hierarchy. PTSEs are exchanged among all members of the group.

PGI

Peer Group Identifier: A string of bits that is used to unambiguously identify a peer group.

PGL

Peer Group Leader: A node which has been elected to perform some of the functions associated with a logical group node.

B-56	Centillion 1200N ATM Switch User Manual
	NTP 297-8103-903