System information

BSR 64000 Configuration and Management Guide
14-2
About SONET/SDH
The Synchronous Optical Network (SONET) standard provides for data transmission
over fiber optic cable and high-bandwidth utilization and efficiency over Internet
links. The SONET standard defines industry interface standards at the physical layer
of the OSI seven-layer model. This standard defines a hierarchy of interface rates that
allow data streams at different rates to be multiplexed. SONET establishes Optical
Carrier (OC) levels from 51.8 Mbps to 2.48 Gbps. Prior rate standards used by
different countries specified rates that were not compatible for multiplexing.
Synchronous Digital Hierarchy (SDH), the international equivalent of SONET,
defines a standard rate of transmission at 155.52 Mbps. With the implementation of
SONET/SDH, communication carriers throughout the world can interconnect existing
digital carrier and fiber optic systems.
Specifications
The BSR POS interface supports the following Request for Comment (RFC)
specifications:
• RFC 1619, PPP over SONET/SDH
• RFC 1662, PPP in HDLC-like Framing
• RFC 2558 SONET/SDH
POS Features
The BSR supports the following POS features:
• Payload scrambling
• Clock source configuration
• Maximum transmission unit size configuration
• SONET/SDH framing
• Cyclic redundancy check
• Alarm Reporting
• Automatic Protection Switching