Sonet/Sdh Uni (Suni); Demux/Mux; Rcmp; Sabre - Cisco BPX-BXM-155-8DX Installation And Configuration Manual

Chapter 5 BXM Card Sets: T3/E3, 155, and 622

SONET/SDH UNI (SUNI)

The SUNI ASIC implements the BXM physical processing for OC-3 and OC-12 interfaces. The SUNI
provides SONET/SDH header processing, framing, ATM layer mapping and processing functions for
OC-12/STM-4 (622.08 Mbps) or OC-3/STM1 (155.52 Mbps).
For ingress traffic, the BXM physical interface:
1.
2.
3.
For egress traffic ATM cells are processed into SONET/SDH frames.
Alarms and statistics are collected at each level: section, line, and path.

DeMux/Mux

The Demux/Mux and associated circuits implement the BXM physical layer processing for T3/E3
interfaces, processing functions for T3 at a 44.736 Mbps rate or E3 at a 34.368 rate. It provides:
•
•
•

RCMP

Usage Parameter Control (UPC) is provided by the RCMP. Each arriving ATM cell header is processed
and identified on a per VC basis. The policing function utilizes a leaky bucket algorithm.
In addition to UPC and traffic policing, the RCMP provides route monitoring and also terminates OAM
flows to provide performance monitoring on an end-to-end per VC/VP basis.
Traffic policing and UPC functionality is in accordance with the GCRA as specified by ATM Forum's
UNI 3.1 using dual leaky buckets.
•
•
In addition, two selective cell discard thresholds are supported for all queues for discard of CLP=1 cells
should congestion occur.

SABRE

The Scheduling and ABR Engine (SABRE) includes both VSVD and Foresight dynamic traffic transfer
rate control and other functions:
•
•
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
Receives incoming SONET/SDH frames,
Extracts ATM cell payloads, and
Processes section, line, and path overhead.
header processing
framing
ATM layer mapping
Leaky Bucket 1 utilizes:
Peak Cell Rate (PCR)
–
Cell Delay Variation Tolerance: CDVT
–
Leaky Bucket 2 utilizes:
– Sustainable Cell Rate (SCR)
– Maximum Burst Size (MBS)
ATM Forum Traffic Management 4.0 compliant ABR Virtual Source/Virtual Destination (VSVD).
Terminates ABR flows for VSVD and Foresight control loops.
Cisco BPX 8600 Series Installation and Configuration
BXM Functional Description
5-27