RS8234EBGC Mindspeed Technologies, RS8234EBGC Datasheet - Page 12

• Manufacturer Part Number: RS8234EBGC
• Description: RS8234EBGC ATM XBR SAR
• Manufacturer: Mindspeed Technologies

1.0 RS8234 Product Overview
1.2 Service-Specific Performance Accelerators
1-4
performing early packet discard based on the frame’s DE field and assigned
discard priority.
IP Interworking
The RS8234 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 RS8234 allows for are as follows:
Guaranteed Frame Rate
The RS8234 can rate-shape ATM Adaptation Layer Type 5 (AAL5) Common Part
Convergence Sublayer Protocol Data Units (CPCS-PDUs, i.e., “frames”) in the
UBR service category, by providing a guaranteed MCR for UBR VCCs.
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).
(i.e., a Virtual FIFO) 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, in
effect, 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.
• ABR signalling for point-to-point calls
• Traffic parameter negotiation
• Frame discard support
• 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 full condition/threshold.
• Various AAL3/4 Management Information Base (MIB) errors.
The user can direct the RS8234 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 employed when
• Programmable ABR templates allow rate-shaping on groups of VCCs to
and the channel exceeding a user-defined priority threshold.
data frames on ELAN channels.
computing a rate adjustment on an ABR VCC.
Mindspeed Technologies
ATM ServiceSAR Plus with xBR Traffic Management
™
28234-DSH-001-B
RS8234