FO Splitter + Cisco SFP

[jamaludeen_s]

Hello,

Could someone clarify about the use of FO splitter in Cisco switching environment, I have a requirement that i will be running 2 core FO cable from Core switch location to access building (60 buildings).

Each access building has 6 edge switches, the plan is to use a 1:8 Fiber optic Splitter at access building to split the 2 core FO cable and connect it to the edge switches. Is this type of connectivity is supported by Cisco?

Do I need to use specific SFP for this design at access and core switches  (Like DWDM, CWDM etc…)

Thanks in advance

Regards

Jamal

[Tom Randstrom · Accepted solution]

You will probably want to review the information under the heading "Cisco CWDM Transceiver Modules" on the URL below.  

http://www.cisco.com/c/en/us/products/interfaces-modules/transceiver-modules/datasheet-listing.html

By deploying CWDM filter modules, one at the central site and a second at the access location, your two fiber cores will become 8 virtual fiber pairs.  The switches will need CWDM transceiver modules to function with the CWDM filters.  There are engineering rules but typical campus envirnments normally fit the network reach limitations. Make sure your switch modules & SW are compatible with the CWDM transceiver modules (link below).  

http://www.cisco.com/c/en/us/support/interfaces-modules/transceiver-modules/products-device-support-tables-list.html  

Good luck!

[jamaludeen_s]

Thanks Tom for the document reference, I appreciate your help 

Regards

Jamal

[jamaludeen_s]

Hi Tom,

One last thing, As per the document the eight transceivers shall be used at access switch location.

CWDM-SFP-1470=

CWDM-SFP-1490=

CWDM-SFP-1510=

CWDM-SFP-1530=

CWDM-SFP-1550=

CWDM-SFP-1570=

CWDM-SFP-1590=

CWDM-SFP-1610=

what transceiver will be used at the core switch location, shall i use a normal SFP or I can select 1 from the above 8 

Regards

Jamal

[Tom Randstrom]

Jamal,

Based upon your question, I think we are discussing different networking architectures.  

You have used the term "splitter".  In basic terms, a splitter is a device that replicates the signal across multiple outputs. A signal is sent in one end and the same data is seen at all the outputs. 

A multiplexer (CWDM/DWDM/etc.) combines or separates independent signals onto (or out of) a common line (fiber). Multiple independent signals are sent in one end and the multiple independent signals are available at the outout.  

To deploy CWDM in your network, the Core switch would require multiple SFP transceivers, each at a different wavelength; which are connected to the appropriate wavelength input on the CWDM filter. The CWDM filter's output connects to the two fiber cores.  At the Access location, a CWDM filter accepts the two fiber cores and provides multiple outputs, which are then connected to the Access switches.      

If you tried to use splitters in your Ethernet network, the Core switches receiver port would have the combined signals from multiple Access switches; the Core switch would be unable to decipher this signal.

Let me know if this helps at all.  I've also provided a link to a document that summarizes some of this information.  

Document: Tranceiver Information with WDM info

https://supportforums.cisco.com/document/52666/transceivers-information

[jamaludeen_s]

Thanks Tom, It helps me a lot. Looks like CWDM solution would be expensive for the customer requirement. i will have to discuss with engineering team to change the topology.

Regards

Jamal 

[marat.sizov]

Does anyone know will two Cisco SFP 1000Base-LH\LX modules work at short distances (less than 10 meters) if they are connected through a passive 1 to 4 optical splitter (PLC technology) that duplicates the signal from the input to 4 output links, but reduces transmission power by 4 times on each output link (proportionally)? The splitter is passive, operates at a wavelength range including 1310 nm. The main question is whether the link between these two SFP will work if the signal level at the reception (Rx) is 20-25% of the signal level of the transmitter (Tx). Don't forget that the distance is very short. I'm not good at measuring the attenuation of a signal in decibels, so a yes-no answer is more preferable. This solution is needed as an alternative to port mirroring by span technology. Thanks for your answers, if they.