Our company network (which I believe is a windows domain run on server 2008) is painfully slow. A prime example of this is copying files over SMB - listings take minutes, and copying even modestly sized files takes even longer. When approached regarding the issue, the IT manager (who, in spite of whatever other merits he might have, is a very stubborn and not a very technical person) throws his hands up, becomes very defensive and gives excuses instead of listening and attempting to work out the root cause of the problem.
Now, recognizing that the human element of this problem will take some time and effort to solve, I am left not knowing quite how to technically rebut his excuses. In this instance, he claims that SMB is the problem, and that it is a "slow" protocol. Is there any evidence for this statement (I only have anecdotal counter evidence)? What is the best way to make headway in this argument?