Since i am using a older version of optisystem so could not able to upload the system file.However as i stated above by taking value of attenuation 0.2dB/Km (default in optical fiber lib. component SMF) you can test it.
Kindly see the screen shot of the system ,i have calculated the value of fiber as
135Km x 0.2dB=27dB
Which corresponds to the attenuation value at attenuator