Turin Networks TE-50, User Manual, Page: 135 / 668

Turin Networks, Inc. Ch 1-8: OC-12 SONET Ring Example
Page 6
The VSF4 interface module is a double width
module with two SFP fiber optic modules
positioned vertically on the Left side of the
module. These SFP modules are connected
to the OC-12 ring and are referred to as port
“A” and port “B”.
SFP port “A”
SFP port “B”
Figure 4 – SFP Port Names
2.1.1 EAST AND WEST
The SDH/SONET ring may have many member nodes, all of which can be accessed on the ring in
either a clockwise or counter-clockwise direction. The directional terminology used to describe the
relative direction to the TE-50-SS is EAST or WEST.
•
The FO interface transmitter in port A is always facing WEST
•
The FO interface transmitter in port B is always facing EAST
2.1.2 SPAN AND RING
The TE-50-SS supports two physical fiber optic interface connection methods:
•
Span per SFP Module
•
Ring per SFP Module
As there are two methods of cabling the fiber optic interfaces into a ring, the direction the FO receiver
faces changes accordingly.
•
In Ring mode (A in, A out), each ring (working and protection) is contained within a single SFP
module.
o
WEST = port A receives from, port B transmits to
o
EAST = port B receives from, port A transmits to
•
In Span mode (A in, B out), each ring (working and protection) transits both SFP modules
o
WEST = port A receives from, port A transmits to
o
EAST = port B receives from, port B transmits to
2.1.3 FIBER OPTIC CONNECTION – SPAN MODE
The Span per interface module connects to both Working and Protection Rings of the same span with
the same fiber optic interface module. Removal of the fiber optic module from port A causes the APS
to switch to protection.
The span mode of connection is suitable for applications of the WDM fiber optic interface option. The
WDM interface uses different transmit and receive wavelengths within a common fiber optic trunk.
The standard fiber optic interface module uses the same wavelength for both receive and transmit but
separated in two fiber optic trunks.