Vishwamurti,

so i should expect to see normally for 1310nm 0.3-0.4dB depending on the distance and 1550nm 0.2 to 0.25dB also depending on the distance? if i get a higher db level say 3-4dB, is that acceptable?

is my understanding correct?

or 1310nm 0.3-0.4dB depending on the distance and 1550nm 0.2 to 0.25dB also depending on the distance

Yes this is the fiber loss you just multiply by distance.

Apart from it you have splice loss which occurs when you join two pieces of fiber length IT depends on how good the splicing was done.

When you will connect a connector to a power meter that will also have some loss.

I was considering all those losses in that 3-4dB. So if you get that kind of loss i think should be fine.

Your distance is so small for a single mode fiber even though it is 10 year old .Even if you want to go for 10G on this fiber i think you will not have any problem unless their is cut or something.

Do you have idea what speed are you considering on this link? Have you decided on what card you want to use.

switches have 10/100 interface so no more than 100mb.

Lastly as an example to clarify by understanding, so to work out the loss say the distance is 1 mile = 1.6km and the loss is 0.3 (taken in to consideration the connector and splice db losses as well!). do i multiply 0.3db by 1.6km = 0.48?

do i multiply 0.3db by 1.6km = 0.48

Yes you have to multiply. Actually these are the general loss figure for single mode fiber. If you need specific for your cable then see if you have any manual of your cable.

100Mb optical port (SFP) for single mode fiber can go 10Km. So i think should go 1.6Km without any problem.

thanks for your help..