Cost Analysis (Fiber Optic Interconnect Ring Topology)

Cost Analysis
(Fiber Optic Interconnect Ring Topology)
The function of the "switch" in this drawing is to break the loop at the node that is
transmitting. That is, if board A is transmitting a fiber optic signal in a fiber optic
medium, the switch causes a break in the loop (i.e. a point where the light ceases to
propagate through the loop) at board A. We are operating on the premise that the
transmitting node couples light onto the fiber optic line and each board couples power off
of the line; in other words, if board C follows board B, C does not depend on B
performing optical-electrical-optical conversion, rather C only depends on B passing light
through its switch onto C.
Following are costs for a NIC, fiber optic switch, and fiber optic cables.

(Summary of Cost Information)
10-Gigabit Network Interface Card: $895.00 at a quantity 4 = $3,580.00
Network Interface Card XFP Tranciever: $900.00 at a quantity 4 = $3,600.00
Fiber Optic Cable: $65.00 at a quantity of 4 = $260.00
High Speed Switches: $1,640.00 at a quantity of 4 = $6,560.00
Total Cost of Proposed Fiber Optic Interconnect: $14,000.00
Requirement Details:
• 4 NIC with 10 Gbit Capabilities
• 20ft. of fiber optic cable (type depending on the NIC selected)
• 4 High Speed Switches ( 2-in/2-out)
10-Gigabit Network Interface Card Recommendation:
Company: Myri-10G 10-Gigabit Ethernet Solutions
Product Code: 10G-PCIE-8A-R
Price: $895.00
Quantity: 4
(Myri-10G PCI-Express NIC with a 10GBase-R port)
Specs can be located on the web at the following address:
http://www.myri.com/Myri-10G/NIC/10G-PCIE-8A-R.html
NIC Specs(Partial):
Myri-10G network port: 10GBase-R, 10+10 Gbit/s data rate, full-duplex. Serial data is
carried on a single fiber in each direction at 10.3125 GBaud, 64b/66b-encoded.
Depending upon the XFP transceiver plugged into the socket in the PCI faceplate, the

port is 10GBase-SR (850nm wavelength, 26-300m on multimode fiber), 10GBase-LR
(1310nm wavelength, up to 10km on single-mode fiber), or 10GBase-ER (1550nm
wavelength, up to 40km on single-mode fiber). The port can operate with either Ethernet
or Myrinet protocols at the Data Link layer. When operating in Ethernet mode, the port
supports Ethernet flow control as defined by IEEE 802.3x. The allowed length of the
fiber cable depends upon the XFP transceiver and the quality of the fiber, but in Myrinet
mode must not exceed 200m due to Myrinet flow control. (See this Brief Guide to Myri-
10G PHYs, pdf, 35KB.)
PCI-Express host port: This NIC is a x8 (8 lane) PCI-Express Add-in Card. It is capable
of exchanging data with a host computer at up to 2 GBytes/s (250 MBytes/s per lane)
data rate in each direction, full-duplex. The port is fully compliant with the PCI-Express
Card Electromechanical Specification Rev. 1.1, and with the PCI-Express Base
Specification Rev. 1.0a. The circuit-board edge connector of the NIC will fit
mechanically in x8 or x16 physical slots in host computers. The NIC auto-negotiates
operation in the widest available mode supported by the slot it is plugged into (x8, x4, x2,
or x1).
NIC Accessories: (XFP tranciever)-XFPs for 10GBase-R. The IEEE 802.3ae 10-Gigabit
Ethernet Standard specifies PHYs with 10.3125-GBaud, 64b/66b-encoded, packet data
over serial fiber at three wavelengths: 10GBase-LR (1310nm, single-mode fiber to 10km)
XFP Price: $900.00
Quantity: 4
Fiber Optic Cable Recommendation:
Company: Stonewall Cable, Inc
Product Number: F083-D22AA0
Product Description: Singlemode 8.3/125 Duplex FC / FC Fiber Optic Cable
Price: $65.00
Quantity: 4
3 meter cables, available from www.stonewallcable.com.

High Speed Switch Recommendation:
Company: Thorlabs
Product Number: FS702
Part Description: 1 x 2 Solid-State Singlemode Fiber Optic Switch, No Connectors
Price: $1,640.00
Quantity: 4
(Solid State Fiber Optic Switch)
Solid-State Fiber Optic Switch Specifications
Min Typ Max
Operating Wavelength 1520nm 1610nm
Switching Speed 50µs 200µs
Insertion Loss 0.7dB 1dB
Cross Talk 40dB 50dB 60dB
Polarization Dependent
Loss
Polarization Mode
Dispersion
0.1dB
0.1ps
Return Loss 55dB
0.2dB
Current Consumption ±120mA ±150mA ±200mA
Drive Voltage 5V
Drive Pulse 0.2ms 0.3ms 10ms
Max optical power 300mW
Dimensions (L) 52 x (W) 7 x (H) 8mm
Fiber 1 meter SMF-28
Operating Temperature 0 70C

-from Thorlabs website.
The fiber optic loop is created when light coming from board n-1 enters the switch from
N.C. (normally closed). With the switch closed, COM then acts as a conduit for the light
coming from N.C. With the switch open, no light is transmitted from N.C. to COM, but
light is transmitting from N.O. (normally open) to COM. With the switch "open" I can
transmit from board n to board n+1 through the switch, and when the light signal has
gone around the loop completely and is coming into the switch from N.C., the light
cannot propagate any farther.
Getting light off of the fiber (for each board's receiver line) could be done by sitting two
such switches back to back, i.e. COM 1 feeding COM2, and then a board could switch
between passing the light from COM 2 to N.C. 2, or receiving the signal into N.O. 2.
However, this would prevent any board farther down the chain from receiving such a
signal. The less painful method would be to have something light a 20dB coupler at COM
to bring 1% of the signal off to any given board's receive and pass 99% of the signal on to
the next board. The choice of coupler is driven by the power output of the transceiver on
board x and the reception threshold for the transceiver on board y.