cn8237 Mindspeed Technologies, cn8237 Datasheet - Page 31

• Manufacturer Part Number: cn8237
• Description: Atm Oc-12 Servicesar Plus With Xbr Traffic Management
• Manufacturer: Mindspeed Technologies

CN8237
ATM OC-12 ServiceSAR Plus with xBR Traffic Management
28237-DSH-001-C
Early Packet Discard
The EPD feature provides a mechanism to discard complete or partial
CPCS-PDUs based upon service discard attributes or error conditions. The
reassembly coprocessor performs EPD functions under the following conditions:
CBR Traffic Handling
The segmentation coprocessor includes an internal rate-matching mechanism to
match the internal rate (the local reference rate) of CBR segmentation to an
external rate (the host rate).
(that is, a Virtual FIFO buffer) for circuit-based CBR traffic.
multiple UBR, VBR, or ABR channels. In addition, the bandwidth of any single
tunnel can be shared by up to four different priorities of traffic, establishing a
multi-service tunnel. This allows proprietary management schemes to operate
under preallocated CBR bandwidths.
ABR Traffic Management
The ABR Flow Control Manager dynamically rate-shapes ABR traffic
independently per VCC, based upon network feedback. One or more ABR
templates are used to govern the behavior of traffic.
• Frame Relay packet discard based on the DE field in the received frame
• Packet discard based on the CLP bit.
• LANE-LECID packet discard to implement echo suppression on multicast
• Packet discard when a firewall condition occurs on a VCC or group.
• Receive FIFO buffer full condition/threshold.
The user can direct the CN8237 to segment traffic from a fixed PCI address
The user can delineate up to 16 CBR pipes (or tunnels) in which to transmit
• Both Relative Rate (RR) and Explicit Rate (ER) algorithms are used when
• Programmable ABR templates allow rate-shaping on groups of VCCs to
• New per-VCC MCR and ICR fields reduce the number of ABR templates
• The CN8237 allows rate adjustments on Turnaround RM cells, based on
• The CN8237 allows rate adjustments due to use-it-or-lose-it behavior.
• The CN8237 generates out-of-rate Forward RM cell(s) to restart
• The CN8237 optionally posts the current Allowed Cell Rate (ACR) on the
and the channel exceeding a user-defined priority threshold.
data frames on ELAN channels.
computing a rate adjustment on an ABR VCC.
be tuned for different network policies.
needed in local memory.
congestion in the host.
scheduling of a VCC whose rate has dropped below the Schedule table
minimum rate.
segmentation status queue for the host monitoring functions.
Mindspeed Technologies
1.2 Service-Specific Performance Accelerators
™
1.0 CN8237 Product Overview
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