342-86400-498PS
Issue 1.2
April 2012
Page 44
Copyright
GE Multilin Inc. 2010-2012
a) CBW tie connections, or
b) Ethernet port tie connections (directly between paddleboards or through
external Ethernet devices).
Each of the above solutions has advantages and disadvantages. The user is
referred to
Tying Ethernet Traffic
in Section 4 for more information.
Note:
When Ethernet traffic is to be passed between networks, caution must be
exercised to ensure that no Ethernet loops are created.
Maintenance Features
The ETHER-1000 unit has several features to monitor the integrity of individual
STS-1 paths to "adjacent" ETHER-1000 units, and to assist in debugging faulty
paths.
The SONET path BER rate and CV errors are determined using the Path
Overhead's B3 bytes of individual STS-1 paths. An STS-1 Path-AIS pattern (all
ones), which usually appears due to a fiber failure, is also detected and reported
through the VistaNET software.
The Path Overhead‟s F2 byte and the two most significant bits in the Z2 byte are
used to carry the information on the number of STS-1 SPEs assigned to the far-
end ETHER-1000 unit (five bits) as well as the information on the STS-1 SPE's
position in the given SPE sequence (five bits) so any mismatched settings at the
near-end Line port, or any changes in the sequence of the received SPEs are
detected and reported. This is handled on per TDM pipe basis.
The 4 most-significant bits of the H4 byte in the Path Overhead can be set to a
user-selectable value while its 4 least-
significant bits are set to “all ones” (hex F).
By monitoring the incoming H4 byte content at the far end, a validity of the SPE
path can be confirmed. This end-to-end SPE path monitoring is performed
through the VistaNET software.
The bits 5 and 4 in the Z2 byte are used to carry a
TDM pipe indicator
to ensure
that that same STS-1 SPEs are used along the given TDM pipe.
The unit is capable of reporting (per TDM pipe) the total number of visible
ETHER-1000 units through each of its Line ports and whether the farthest visible
unit is the local unit (ring network), a terminal/end unit (linear network) or if there
is a path break upstream.
