CN8236EBGB Mindspeed Technologies, CN8236EBGB Datasheet - Page 31

• Manufacturer Part Number: CN8236EBGB
• Description: ATM SAR 155Mbps 3.3V ABR/CBR/GFR/UBR/VBR 388-Pin BGA
• Manufacturer: Mindspeed Technologies

Specifications of CN8236EBGB

• Package: 388BGA
• Traffic Class: ABR|CBR|GFR|UBR|VBR
• Utopia Type: Level 1|Level 2
• Host Interface: PCI
• Maximum Data Rate: 155 Mbps
• Typical Operating Supply Voltage: 3.3 V
• Minimum Operating Supply Voltage: 3 V

CN8236
ATM ServiceSAR Plus with xBR Traffic Management
28236-DSH-001-B
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.
transmit 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.
VBR Traffic Management
The CN8236 schedules each VBR VCC according to GCRA parameters stored in
the individual VCC control tables. The internal xBR Traffic Manager schedules
the transmitted data to maximize the permitted link utilization. The actual rate
sent is accurate to within 0.15% of the negotiated rates over a range from 10 cells
per second to full line rate of 155 mbps.
Virtual Path Networking
The CN8236 can interleave segmentation of numerous VCCs (that is, separate
VC channels) as members of one Virtual Path (VP). VP-based traffic shaping is
supported. The entire VP is scheduled according to parameters for one VCC.
The user can direct the CN8236 to segment traffic from a fixed PCI address
The user can delineate up to sixteen CBR pipes (or tunnels) in which to
• Both Relative Rate (RR) and ER algorithms are used when computing a
• 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 CN8236 allows rate adjustments on Turnaround RM cells, based on
• The CN8236 allows rate adjustments due to use-it-or-lose-it behavior.
• The CN8236 generates out-of-rate Forward RM cell(s) to restart
• The CN8236 optionally posts the current Allowed Cell Rate (ACR) on the
Three VBR modes are supported:
• Sustained cell rate (one leaky bucket)
• Peak and sustained cell rate (dual leaky bucket)
• CLP 0+1 shaping (supports committed/best effort services)
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.
(This is the mode recommended by the Internet Engineering Task Force
[IETF] as the most convenient model for IP over ATM interworking.)
Mindspeed Technologies
1.2 Service-Specific Performance Accelerators
™
1.0 CN8236 Product Overview
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