cn8237 Mindspeed Technologies, cn8237 Datasheet - Page 30

• 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
1-4
UNI or NNI Addressing
The CN8237 handles both User-Network Interface (UNI) addresses, which use an
8-bit Virtual Path Identifier (VPI) field, and Network-to-Network Interface (NNI)
addresses, which use a 12-bit VPI field.
Frame Relay Interworking
The VBR traffic category includes rate-shaping via the dual leaky bucket Generic
Cell Rate Algorithm (GCRA) based on the Cell Loss Priority (CLP) bit, for use in
Frame Relay. The CN8237 also implements the Frame Relay discard attribute by
performing early packet discard based on the frame’s DE field and assigned
discard priority.
IP Interworking
The CN8237 facilitates ATM call control signalling procedures as defined in
ATM Forum’s UNI Signalling 4.0 Specification (SIG 4.0), to support IP over
ATM environments. Some of the SIG 4.0 capabilities that are of interest to IP over
ATM and which the CN8237 allows for are as follows:
Guaranteed Frame Rate
The CN8237 can rate-shape ATM Adaptation Layer Type 5 (AAL5) Common
Part Convergence Sublayer Protocol Data Units (CPCS-PDUs, that is, frames) in
the UBR service category, by providing a guaranteed Minimal Cell Rate (MCR)
for UBR VCCs.
• ABR signalling for point-to-point calls
• Traffic parameter negotiation
• Frame discard support
Mindspeed Technologies
ATM OC-12 ServiceSAR Plus with xBR Traffic Management
™
28237-DSH-001-C
CN8237