At the very least enough of a map to make all of the network infrastructure clear. Unfortunately I can't send you any good examples I have as they would tend to be customer networks. The more detailed the better.
It is not impossible, though not my first guess either, that the call may come to the point of wondering if you have a loop by the end of it, so he may have to start looking at phrases like "every wire connected to the DES-1228P" by the end of this.