This document is a survey of network security protocols and their interaction with transport and application protocols. It is clearly written and easy to read. I have a minor comment on the contents of this draft.

It is not abundantly clear what the criteria was for selecting the subset of security protocols included in this draft. Some notable omissions include SSH, L2TP, and GRE. These seem like interesting omissions given their popularity in a number of deployment scenarios. Not a showstopper in my opinion, but interesting to note.