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 short draft defines an extension to the Dynamic Link Exchange Protocol (DLEP) that enables an Ethernet-based flow control mechanism for traffic sent from a router to a modem. The Security Considerations section of the draft resembles similar sections in other documents defining DLEP extensions, mostly stating that adversary able to inject DLEP messages can mount a DoS attack. I wish more details are given on what type of DoS attacks are possible (e.g. advertising too large or too small window, or associating it with wrong type of traffic, etc.), but this is only my personal preference. The draft mentions the possibility to use security mechanisms defined in RFC8175 (base DLEP specification), but with no BCP14 wording like "RECOMMENDED" or "SHOULD" (other DLEP extension documents that I looked into do not have BCP14 language on using these security mechanisms either).