11-19-2010 09:22 AM
The requirement for lossless Ethernet comes in part from the ANSI standard for Fibre Channel over Ethernet (FCoE) which just states that FCoE frames must be transported over lossless Ethernet, and then leaves the details on how to accomplish that to IEEE, the folks responsible for developing Ethernet standards. Note, lossless Ethernet has value for other kinds of traffic using Ethernet as the transport, for example, iSCSI storage traffic.
IEEE uses the term "Data Center Bridging", or DCB, for all the extensions to Ethernet required for lossless forwarding of Ethernet frames.
Ok, but how does VCS technology handle lossless Ethernet traffic?
Since VCS technology is used to create an Ethernet fabric between multiple VDX switches, and since the fabric ports have to forward any kind of Ethernet traffic, VCS ensures that links between VDX switches are lossless. That makes sense. If the Ethernet fabric is lossless (a stringent requirement for Ethernet) then there won't be any problems when devices sending FCoE, or other lossless traffic types in the future, connect to a VDX switch.
BUT WAIT, THERE'S MORE ---> NO manual configuration is required, so this is easy, peasy.
But, does this require devices (servers, other switch ports) connected to a VDX switch to support the DCB extensions? Okay, what do you think the correct answer is to this question?
Made up your mind? Good. Now go look at the post in Ask the Experts to see if you got this one right.