I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments. The terminology RR (Request Router) and CP (Content Provider) specified by the Terminology are not used for the entire document. I assume that RR would be the one request content, isn't? is RR same as Client? Is RR part of Downstream CDN Provider? is the CP same as Downstream CDN provider or Upstream CDN Provider? who issued the Redirect Target? It would be good for the document to clearly specify the relationship of all the entities, such as who makes request and who respond, and who use the Redirect Target capability, etc. Thank you very much. Linda Dunbar