A SearchStorage.com reader recently asked:
I am attempting to set up an extended fabric over DWDM. I have two 32-port Brocade 3900 switches on either end, both running version 4.1.2 Fabric OS. We have two Nortel OPTera Metro 5200 (DWDM) cards on either end. Unfortunately, I have found out that these cards do not provide local buffering, therefore, I must set up an extended fabric via the switches.
I have turned on long distance mode on all switches in the fabric. I have made sure that each port connected to our DWDM cards, is the only port used on the ASIC (since buffers are shared across the ASIC). I have attempted to set the connected ports to the L2 long-distance level (command used: portcfglongdistance port# L2 1). With all the settings in place, I am still receiving CRC errors when running various spinfab/port tests.
I believe that my problem may be that I am not currently using Extended Long Wave (ELW) SFP modules (I am currently just using 2 GB SFP LC modules).
Before I purchase a few of these modules (and the appropriate 9 micron single-mode fiber optic cables), I thought I'd confirm if others agree with my assessment of the situation. If not, what else might I be missing?