Technical data

TraverseEdge 2020 Applications and Engineering Guide, Chapter 3: System Applications
Page 3-56 Turin Networks Release 5.0.x
SONET
The GbE PLM provides full SONET path termination functions for each of the STS-Xc paths that make up
an STS-Nc-Xv connection, including path layer performance monitoring and path layer alarm surveillance.
Protection
The GbE PLM relies on the standard protection capabilities of SONET to provide sub-50 ms network sur-
vivability for GbE traffic. Each STS-Nc-Xv connection that carries GbE traffic may be protected as any
other SONET connection is protected.
Facility protection has not been defined for optical GbE interfaces, as it has for SONET facilities. For this
reason, the GbE PLM does not provide facility protection for GbE interfaces. Because the GbE PLM pro-
vides transparent transport of Ethernet frames, it does not interfere with higher layer restoration schemes
run by client systems. All forms of layer 2 and layer 3 re-routing, as well as 802.3ad link aggregation, will
work correctly over Turin Networks EoS.
3.10.9 Virtual Concatenation
Virtual concatenation comprises octet-oriented inverse multiplexing of a data stream into multiple SONET
STS paths, transport of each STS path across a standard SONET network, and recombination of the path
payloads into a contiguous octet stream at the end point of the transmission. The GbE PLM and FastE
PLM use virtual concatenation to provide a standard, interoperable, right-sized SONET connection for line
rate GbE transport.
The GBE PLM supports two virtually concatenated STS-Nc-Xv connections or standard SONET connec-
tions (defined in Table 3-21 ), one for each GbE port. The Fast Ethernet PLM supports both Virtual concat-
enation connections and standard SONET connections as given in Table 3-20 . Line rate for Fast Ethernet
is achieved using 2 STS-1 connections or using VC nomenclature STS-1-2v.
Table 3-21 Gigabit Ethernet Cross-Connects and VC group types
Nomenclature Contents
STS-1 A single STS-1. No Virtual Concatenation is used. The user should select the STS-1 sig-
nal type not the VC signal type to implement this connection.
STS-3c A single STS-3c. No Virtual Concatenation is used. The user should select the STS-3c
signal type not the VC signal type to implement this connection.
STS-12c A single STS-12c. No Virtual Concatenation is used. The user should select the STS-12c
signal type not the VC signal type to implement this connection.
STS-1-Nv N Virtually concatenated STS-1s using a VC group; N = 1..21
NOTE: An STS-1-1v is a single STS-1 VC group. It is not the same as using a single
STS-1 (H4 SONET overhead byte is different). A user may choose this option if the ini-
tial signal is a single STS-1 but in the future may grow to multiple STS-1s. The VC
group could then be modified.