deploying and managing ip over wdm networks - Index of

Management of the WDM Network Layer 59
• Optical channel overhead processes for ensuring integrity of the optical
channel adapted information. For instance, the connectivity integrity is
validated, the transmission quality is assessed, and transmission defects
are detected and indicated. Failures detected by the OCh layer will lead
to a server signal fail towards the client layer.
• Optical channel supervisory functions for enabling network-level
operations and management functions, such as connection provisioning,
quality of service parameter exchange, and network survivability.
All supervision functions apply to the OCh layer. In case there is no
possibility for rearranging network connections on the OCh layer, no
supervision function for connectivity is required.
4.3.1.2 OMS Layer
This layer provides functionality for networking of a multiwavelength optical
signal; this is a grouping of OChs. The capabilities of this layer include:
• Optical multiplex section overhead processes for ensuring the integrity
of the multiwavelength optical multiplex section–adapted information;
failures detected at the OMS layer will lead in turn to a server signal fail
at the OCh layer.
• Optical multiplex section supervisory functions for enabling sectionlevel
operations and management functions, such as multiplex section
survivability. In contrast to the OCh layer, the OMS layer does not
have connectivity supervision function because there is a one-to-one
relationship between the OTS and the OMS layers. Other supervision
functions are for further study (e.g., signal quality supervision).
These networking capabilities performed for multiwavelength optical signals
provide support for operation and management of optical networks.
4.3.1.3 OTS Layer
This layer provides functionality for transmission of optical signals on optical
media of various types (e.g., ITU G.652, G.653, and G.655 fiber). The capabilities
of this include:
• Optical transmission section overhead processing for ensuring the
integrity of the optical transmission section–adapted information; characteristic
information is inserted to retrieve information about the optical
signal quality. This characteristic information is referred to as an
optical transport module (OTM).