FCoE Links

[visitor68]

A converged10G  FCoE link carries data and storage traffic. By default, how is that 10G link divided between the two types of traffic?

[smehrnia]

hi,

Fibre Channel over Ethernet (FCoE) is a protocol specification to encapsulate Fibre Channel frames in Ethernet packets to enable unified I/O connectivity on a server. below figure:

With FCoE technology, servers, instead of having multiple discrete I/O adaptors for LAN and SAN traffic, will have a smaller number of converged network adapters (CNAs) that support both LAN and Fibre Channel SAN traffic.

plz Rate if it helped.

Soroush.

[visitor68]

Soroush, thank you but this does not help at all. This is not what I am asking. I am very well versed in FCoE encapsulation, etc. I am asking how the bandwidth is carved on a 10G link between FCoE and IPoE.

There is a default setting in Nexus switches for the division of traffic. I believe it is 60% IP and 40% FCoE

[smehrnia · Accepted solution]

hmm... i didnt get ur question right then. if you are asking about the logical method of bandwidth allocation.

as far as i know the default is 50 - 50 for FCoE and Ethernet traffic and Nexus switches achieve this by using QoS WRR scheduling queues. specifying CoS values for packets and assigning them to queues and so on...

you can manipulate this behavior by modifying the 802.1p CoS values, associated with the classes.

did i get u right this time or not?

[visitor68]

Sort of - you are understanding my question, but I am not sure you are right about the BW allocation percentages. Thanks.

[visitor68]

Soroush:

I just found the document,. You are right - it is a 50-50 split by default.

Good work.

Thanks

http://www.cisco.com/en/US/docs/switches/datacenter/nexus5000/sw/operations/n5k_fcoe_ops.html#wp1079830