Hi, 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. Integrating Robust Header Compression (ROHC) with IPsec (ROHCoIPsec) offers the combined benefits of IP security services and efficient bandwidth utilization. However, in order to integrate ROHC with IPsec, extensions to the SPD and SAD are required. This document describes the IPsec extensions required to support ROHCoIPsec. While not a security issue, I believe that you should include the expansion of ROHC in the Abstract. I believe the security considerations section adequately provide guidance for the pitfalls of poor algorithm choice and known traffic analysis attacks. -derek -- Derek Atkins 617-623-3745 derek at ihtfp.com www.ihtfp.com Computer and Internet Security Consultant