Cisco Systems MGX 8230 Cell Loss Priority

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Cisco MGX 8230 Edge Concentrator Installation and Configuration
Release 1.1.31, Part Number 78-11215-03 Rev. B0, May 2001
Chapter2 Module and Service Descriptions Frame Relay Service Modules
Cell Loss Priority
In addition to frame-to-cell and DLCI-to-VPI/VCI conversion, the SIW feature maps cell loss priority
(CLP) and congestion information from Frame Relay-to-ATM formats and is FRF.8-compliant. It
provides full support f or r o ut ed and bridged PDUs, t ra nsparent and transla tio n modes, and VP
translation. The CLP an d congestion parame t e r s c a n be modified for individu a l co nnections with the
cnfchanmap command.
Frame Relay–to–ATM Direction
Each Frame Relay– to–ATM service interworking connection can be co nfigured as one of the following
Discard Eligibility (DE ) to Ce ll Loss Priority (CLP) sch emes:
•DE bit in the Frame Relay f r am e is m a p pe d to th e C LP bit of every ATM cell generated by the
segmentation process of the fram e.
•CLP is always 0.
•CLP is always 1.
ATM–to–Frame Relay Direction
Each Frame Relay– to–ATM service interworking connection can be co nfigured as one of the following
CLP to DE mapping sc he m es :
•If one or more ATM cells belonging to a frame has its CLP set, the DE field of the Frame Relay
frame will be set.
•DE is always 0.
•DE is always 1.
Setting up the cell loss priori ty option is accomplished through the MGX 8220 cnfchanmap (configure
channel map) command.
Congestion Indication
Frame Relay–to–ATM Direction
Each Frame Relay– to–ATM service interworking connection can be co nfigured as one of the following
Forward Explicit Congestion Notification (FECN) to Explicit-Forward Congestion Indicator (EFCI)
schemes:
•FECN bit in the Frame Re la y f r am e is m ap pe d to the EFCI bit of every ATM cell gene r ate d by the
segmentation process of the fram e.
•EFCI is always 0.
•EFCI is always 1.
ATM–to–Frame Relay Direction
Frame Relay– to–ATM service interworking connections use the following EFCI to FECN /B ECN
mapping schemes:
•If the EFCI bit in the last ATM cell of a segmented fram e received is set to 1, the FECN of the Frame
Relay frame will be set to 1.
•BECN is always set to 0.
•Setting up the congestion indication option is accomplished through the cnfchanmap (configure
channel map) command.