cn8237 Mindspeed Technologies, cn8237 Datasheet - Page 32

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

1.0 CN8237 Product Overview
1.2 Service-Specific Performance Accelerators
1-6
VBR Traffic Management
The CN8237 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 600 Mbps.
Virtual Path Networking
The CN8237 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.
AAL for Proprietary Traffic
The CN8237 incorporates an AAL0 traffic class for both segmentation and
reassembly, which acts as an AAL level for proprietary use. Several options for
packetization are implemented.
Internal SNMP MIB Counters
CN8237 has three internal counters that measure cells received, cells discarded,
and AAL5 PDUs discarded (to meet ILMI and RFC1695 requirements).
CompactPCI Hot Swap
Circuity and I/O have been added in to functionally comply with the CompactPCI
Hot Swap Specification. Electrical compliance is pending analysis. Refer to
Sections 7.2 and 3.1.8 of the PICMG Hot Swap Specification (PICMG 2.1 R1.0)
for details of the Hot Swap operation. The HSWITCH* input indicates the state
of the handle switch. A logic low indicates that the handle is locked, whereas a
logic high indicates that the handle is unlocked. The HLED* output is a 12 mA
open drain capable of driving an LED directly. A logic low illuminates the LED.
The HENUM* output is an 8 mA open drain in compliance with the ENUM#
signal defined in the CompactPCI specification.
NOTE:
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)
(This is the mode recommended by the Internet Engineering Task Force
[IETF] as the most convenient model for IP over ATM interworking.)
If HSWITCH* is not used, it must be tied to ground.
Mindspeed Technologies
ATM OC-12 ServiceSAR Plus with xBR Traffic Management
™
28237-DSH-001-C
CN8237