Hi Paul, Should we make the observation that, since the MPLS forwarding plane does not offer any security features, if security is required it must be provided by the SFC layer using some mechanisms inherent in the NSH. We could/should probably also observe that, as yet, no NSH security mechanisms have been defined. Cheers, Adrian -----Original Message----- From: ietf <ietf-bounces@xxxxxxxx> On Behalf Of Paul Wouters Sent: 17 February 2019 23:58 To: secdir@xxxxxxxx Cc: mpls@xxxxxxxx; draft-ietf-mpls-sfc-encapsulation.all@xxxxxxxx; ietf@xxxxxxxx Subject: Secdir last call review of draft-ietf-mpls-sfc-encapsulation-02 Reviewer: Paul Wouters Review result: Ready 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 summary of the review is Ready While I'm not familiar with the Service Function Chaining (SFC) architecture and the Network Service Header (NSH), the Security Considerations in this document seem to be correct in pointing out that: This document simply defines one additional transport encapsulation. The NSH was specially constructed to be agnostic to its transport encapsulation. As as result, in general this additional encapsulation is no more or less secure than carrying the NSH in any other encapsulation.