I am often told by Sales Engineers and Product managers that a Layer 2 Ethernet service is not fit for purpose if the maximum supported frame size is in the 1518-1522 range (enough to support standard Ethernet frames or VLAN tagged frames).
Or in other words: an MTU of 1500 is not enough (see this blog post for my definition of MTU and a short rant on how the term is often misused)
I am never able to get any details from them on:
a) What proportion of customers (Enterprise / SMB) require Jumbo frames
b) What are typical expectations on frame size for Jumbos on WAN links? 1600, 2000, 9k, etc...
I know that in Telco and Data Centre environments Jumbos are pretty common, but I am after some insight as to how common this is within Enterprise and SMB networks.