Cisco BPX 8600 Series, Руководство по установке и настройке

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Glossary
18
Cisco BPX 8600 Series Installation and Configuration
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
S
SSAR
(Segmentation and
Reassembly) The process of breaking a dataframe containing data from a number of virtual paths or circuits apart
so that the individual paths/circuits can be switched by reassembling the data into a new frame with a
different sequence.
SCM (System Clock
Module)
An IGX backcard that works in conjunction with the NPM. The SCM provides a centralized clock
generation function and provides serial and LAN port interfaces.
SCR (Sustainable
Cell Rate) Rate above which incoming cells are either tagged or discarded.
SDP (Synchronous
Data PAD)
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.
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 (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.
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.
speech detection
Determining the presence or absence of speech for Digital Speech Interpolation. Performed in either
the CDP card.
split clock
A data clocking configuration where the timing for the transmit data is obtained from one source (such
as a user device) and the timing for the receive data is obtained from another source (such as a switch).
Status Enquiry
A message transmitted by a FR NNI port requesting an updated status from the attached foreign
network. This message is used as a heartbeat to detect when a port has failed.