> This issue is my turning up new MX960's that are simply connected together > with Ciena 6500 DWDM.... for me to have an MTU issue via DWDM is actually a > surprise to me. I pretty much always envisioned wave/lamda dwdm as darn near > like having an actual fiber cable... no, not the case apparently... I'm > surprised that the ciena dwdm service in this case is actually imposing an > Ethernet mtu limitation ! wow, the more I think on it, the more I'm > surprised about it... previously my older asr9k 15-node mpls ring was via > fujitsu flashwave dwdm and I don't recall this occurring
DWDM is kind of agnostic in the core but for packet networks there are OTU frames (max size = 16,320 bytes) and there is also the interface line card that imposes the actual MTU for the Ethernet interface (9600 is a well-known value for DWDM networks). If you have, say, a 100G transponder and a 10x10G line card then you have to frame all those ports, they won't become light as 10G channels. Even 10G channels on a regular 10G non-coherent network must be framed for FEC and everything else. If you have a colored interface directly from your router to the DWDM system then you might skip that limitation (that depends on the platform and linecard configuration). Luis _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
