Transition Networks C4110-4848, Инструкция по установке

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Transition Networks S4110 Install Guide
33573 Rev. B https://www.transition.com/ Page 15 of 20
SONET (Synchronous Optical Transport Network)
S ynchronous Optical Net work, a standard for connecting fiber-optic transmission systems. SONET was
proposed by Bellcore in the middle 1980s and is now an ANSI standard.
SONET defines interface standards at the physical layer of the OSI seven-layer model. The 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 (OC-1) to 9.95 Gbps (OC-192). The international
equivalent of SONET, standardized by the ITU, is called SDH.
SONET and Synchronous Digital Hierarchy (SDH) are standardized protocols that transfer multiple digital
bit streams synchronously over optical fiber using lasers or highly coherent light from light-emitting diodes
(LEDs). At low transmission rates data can also be transferred via an electrical interface. The method was
developed to replace the Plesiochronous Digital Hierarchy (PDH) system for transporting large amounts
of telephone calls and data traffic over the same fiber without synchronization problems. SONET generic
criteria are detailed in Telcordia Technologies Generic Requirements document GR-253-CORE.
Both SDH and SONET are widely used today: SONET in the United States and Canada, and SDH in the
rest of the world. Although the SONET standards were developed before SDH, it is considered a variation
of SDH because of SDH's greater worldwide market share. SONET and SDH often use different terms to
describe identical features or functions. This can cause confusion and exaggerate their differences. With
a few exceptions, SDH can be thought of as a superset of SONET.
Messages
Message : Setting values failed (snmp operation error, possible reasons: invalid data, error data
sequence, etc)
Meaning : The selected parameter setting was not recognized.
Recovery : Click the Refresh button to clear the error message.
Message : The DMI feature is not supported on current port.
Meaning : Either the port or the SFP does not support DMI, or an SFP is not currently installed in Port 1.
Recovery : Either insert an SFP/SFP+ in Port 1, or change to Port 1, or change SFPs to a type that
supports DMI. See notes above for SFP DMI support.