Cisco BPX 8650, Installation And Configuration Manual

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Glossary
GL-19
Cisco BPX 8600 Series Installation and Configuration
Release 9.3.30, Part Number 78-12907-01 Rev. E0, May 2005
SCR
sustainable cell rate.
Rate above which incoming cells are either tagged or discarded. Long term limit on the rate a
connection can sustain.
SCT
A set of data structures that map VSI service types to sets of pre-configured VC and Qbin parameters.
Consists of two sub-components—a VC Descriptor Template and a Class of Service Buffer descriptor
template.
SDI
synchronous data interface.
The back card for the HDM (IGX switch) cards. The SDI is available with V.24, X.21, and V.35
interfaces.
SDP
synchronous data packet assembler/disassembler.
SDP is used to connect simple synchronous data devices that do not support the full functionality of
a particular protocol to a network.
PADs buffer data, assemble, and disassemble packets sent to end devices.
segmentation and
reassembly
See SSAR.
serial interface unit
See SIU.
service class (aka
service type)
A concept for grouping connections that share a common set of traffic characteristics and QoS
requirements. The terms “service class” and “service type” are sometimes used interchangeably. In
this release, there are some major service categories, such as VbrRt, VbrNRt, CBR, ABR, and UBR,
and under these major service categories are service types such as VbrRt1, VbrRt2, VbrRt3, and
VbrNRt1, VbrNrt2, and so on. Sometimes the terms service class and service type are used
interchangeably.
service class
database
The collection of data items that support the service class template concept, and implemented on a
per-VI basis on the BXM. These items include a copy of the specific Service Class Template selected
for a VI, as well as additional data as required.
service class
template
See SCT.
SES
The Service Expansion Shelf is the controller on which the BPX’s PNNI implementation runs. It is
SPARC-based.
simple gateway
Refers to FastPacket to ATM interworking with respect to the IGX node. In the simple gateway mode,
FastPackets are encapsulated in their entirety into cells. Compare with complex gateway.
SIU
serial interface unit.
A set of circuits common to all BPX cards used for transmitting and receiving via the crosspoint
switch.
soft PVC
A PVC in the INS Dial-Up Frame Relay application that is dormant in the networks database until it
is activated by a call into the network by a user.
spanning tree
An network topology in which there is only one path available between any two sources in a frame
relay multicast group. Spanning trees are required to prevent frames broadcast from a single source to
multiple receptors from circulating endlessly around the network a result of frame relay circuits not
having properly closed loops.