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 informational draft describes use cases for the Congestion Exposure (ConEx) protocol to facilitate efficient traffic management. It also describes the reasoning of using ConEx markings at the IP layer. The security consideration section does exist and defers to the ietf-conex-abstract-mech draft. The security consideration section of ietf-conex-abstract-mech draft defers to section 4.4, which is on auditing. This really should be in its own security consideration section and should extract specific security threats and how they are mitigated. General comments: Not being a ConEx expert, I didn't know what "ConEx markings" really meant when initially reading the abstract. Editorial comments: None. Shawn. --