09-13-2011 11:50 AM
As andreas a'm confused about you mentioning "spoofing" has nothing ot do with distance.
What Andreas and I where talking about is boils down to this>>
Yes you can run 4 ISL's @8G over 120km if your DWDM actively participates in buffer reservation.
If your DWDM boxes are passive then Yes you can run 4 ISL's @8G over 120km BUT won't be able to utilyze your ISL's to there full potential due to buffer credit starvation (running out of credits before credit are retuned from the other end) thus no more frames are put on the wire until a credit returns.
09-13-2011 12:25 PM
If just scanned it and it looks like Cisco's buffer credit spoofing does/is the same and/or has the same result as buffer credit participation.
To my understanding the local Cisco DWDM box wil acknowledge the local switch frames, thus returning the credit to the local switch.
The same applies to the other end.
The DWDM boxes are responsible for maintaining credits (or whatever Cisco care to name them) and troughput on the DWDM link.
This is exactly what Brocade means when they talk about active buffer credit reservation.
The local switches need only have enough credits to reach their local DWDM box.
Depending on the distance between your B300 and DWDM box this will work, but you have to be sure:
-the dwdm box and B300 are close enough (calculate en measure the figures needed).
-B300 and dwdm box need to be compatible (check ISL R_RDY mode and IM)