EGlossary
B-26 Centillion 1200N ATM Switch User Manual
NTP 297-8103-903
EN
European Norm
End Station
These devices (e.g., hosts or PCs) enable the communication between ATM end
stations and end stations on "legacy" LAN or among ATM end stations.
Entry Border Node
The node which receives a call over an outside link. This is the fi rs t node within a
peer group to see this call.
EPD
Early Packet Discard: A congestion control technique that selectively drops all but
the last ATM cell in a Classical IP over ATM packet.When congestion occurs, EPD
discards cells at the beginning of an IP packet, leaving the rest intact.The last cell
is preserved because it alerts the switch and the destination station of the beginnin g
of a new packet.Because IP packets from cells have been discarded receive no
acknowledgment from the source. Most vendors expect EPD to be used in
conjunction with unspecified bit rate (UBR) service. Switches simply junk UBR
cells when congestion occurs, without regard for application traffic.By discarding
ceiling selectively. so that whole IP packets are resent, EPD makes UBR a safer
option.
ER
Explicit Rate: The Explicit Rate is an RM-cell field used to limit the source ACR
to a specific value. It is initially set by the source to a r equested ra te (such as PCR).
It may be subsequently reduced by any network element in the path to a value that
the element can sustain. ER is formatted as a rate.
ES
End System: A system where an ATM connection is terminated or initiated. An
originating end system initiates the ATM connection, and terminating end system
terminates the ATM connection. OAM cells may be generated and received.
ESD
Elastic Discharge
ESF
Extended Superframe: A DS1 framing format in which 24 DS0 times lots plus a
coded framing bit are organized into a frame which is repeated 24 times to form a
superframe.