Glossary Q
Centillion 1200N ATM Switch User Manual B-61
NTP 297-8103-903
PTSE
PNNI Topology State Element: A collection of PNNI information that is flooded
among all logical nodes within a peer group.
PTSP
PNNI Topology State Packet: A type of PNNI Routing packet that is used for
flooding PTSEs among logical nodes within a peer group.
PVC
Permanent Virtual Circuit: This is a link with static r ou te defined in advance,
usually by manual setup.
PVCC
Permanent Virtual Channel Connection: A Virtual Channel Connection (VCC) is
an ATM connection where switching is performed on the VPI/VCI fields of each
cell. A Permanent VCC is one which is provisioned through some network
management function and left up indefinitely.
PVPC
Permanent Virtual Path Connection: A Virtual Path Connection (VPC) is an ATM
connection where switching is performed on the VPI field only of each cell. A
Permanent VPC is one which is provisioned through some network management
function and left up indefinitely.
Q
QD
Queuing Delay: Queuing delay refers to the delay imposed on a cell by its having
to be buffered because of unavailability of resources to pass the cell onto the next
network function or element. This buffering could be a result of oversubscription
of a physical link, or due to a connection of higher priority or tighter service
constraints getting the resource of the physical link.
QoS
Quality of Service: Quality of Service is defined on an end-to-end bas is in terms of
the following attributes of the end-to-end ATM connection:
• Cell Loss Ratio
• Cell Transfer Delay
• Cell Delay Variation