ATM Services Configuration Guide for CBX 3500, CBX 500, GX 550, and B-STDX 9000 5-1
Beta Draft Confidential
5
About the ATM FCP
The ATM Flow Control Processor (FCP) is an optional feature that supports ATM 
traffic management through binary, hop-by-hop, closed-loop flow control algorithms 
that shift network congestion to the edge of the network. In addition, the FCP uses 
several per-virtual circuit (VC) cell/packet queuing and discarding mechanisms for 
additional network congestion control.
Based on the ATM Forum’s Traffic Management Specification, Version 4.0, the 
ATM FCP delivers a fair, deterministic service for bursty ATM traffic, including:
• Dynamically adjusting the allowed cell rate (ACR) in response to resource 
management (RM) cell feedback
• Reducing congestion in the network by adjusting the data rate at which a VC 
sends cells
• Fair resource allocation based on the minimum cell rate (MCR)
• Per-VC queuing with early packet discard/partial packet discard (EPD/PPD) 
capability