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.

This document describes a routing mechanism for Peer-to-Peer Session Initiation Protocol (P2PSIP). The routing mechanism in the base P2PSIP protocol specifies an initiator sending a request message hop by hop through a DHT to a responder, with the responder returning a reply using the reverse path. The alternative routing method defined in this I-D describes a shortcut for the response message. The response is returned directly to the initiator using an IP address provided by the initiator. This shortcut method is described as an optimization that is useful in private networks where a self-reported IP address is likely to be reliable (i.e., no NAT).

I previously reviewed draft-ietf-p2psip-drr-10 and had some clarification questions and minor comments. This version adequately addressed those comments, and I have no additional concerns.

The only thing that I wish could be clarified in the draft is that the "DRR(DTLS)" values for "No. of Msgs" values in Table 1 and Table 2 assume that the DTLS session had been setup previously, so the cost of those messages is thus not included in this table. That's fine, but the cost of setting up that session might not be obvious to someone looking at the tables and it would be worth pointing it out explicitly in the text. But this is not a security consideration concern, only a suggestion to make the draft easier to understand.

Brian