Inter-exchange media types

Dtatacom tests were performed in the 10/100 setup. Obviously
the Fast ethernet switches had an advantage over the FDDI
switches since Fast ethernet and conventional ethernet work
with the same frame types. FDDI switches on the other hand
has to convert ethernet frames to FDDI frames and vice versa.
Todays NAPs in most cases are not 10/100 set up. It is more like
DS3/100/100 setup where routers are feeding traffic into the Gigaswitch
using FDDI and since HSSI and FDDI is using same MTU size, no
fragmentation is involved.

Both 10 and 100 ethernet use 1500 byte mtu.

And remember that the characteristics of a loaded exchange is very
diffrent between ethernet and token-ring.