Hi!

Review of	draft-ietf-mops-treedn
Type	Telechat Review
Team	Internet Area Directorate (intdir)
Reviewer	Carlos Pignataro 

This document describes TreeDN, a tree-based CDN architecture designed to address  scaling challenges of live streaming to mass audiences. This is achieved through Source-Specific Multicast (SSM), including PIM-SSM, and tunneling or overlays based on Automatic Multicast Tunneling (AMT).

The overall architecture and document seem clear and largely complete. At times it might read a bit marketing-ish (e.g., S3, is this solving for all multicast?), though the technical details are comprehensive. This is an Informational-targeting document.

From a document clarity perspective, there's an opportunity to earlier on summarize what the architecture is. Interestingly, IDnits flags that there is no "Introduction" section. While I do not believe an Introduction is mandatory, early text describing TreeDN will help. Specifically, something like:
   "TreeDN is essentially the synthesis of SSM plus overlay networking
   technologies like AMT to deliver traffic to receiving hosts on
   unicast-only networks, or directly natively on-network when there's support for support multicast."

From an Int-Area perspective, I feel some of the coverage of tunneling + multicast is lacking. For example, specifically, generation, treatment, defaults, throttling, processing of ICMP Error messages. The document does not include the acronym "ICMP", yet I believe it is important particularly for AMT.

Further, combining this Int-Area perspective with some added operational aspects, manageability (from defaults to toolset) seem also highly lacking.

I hope these are clear and useful.

Thank you!

Carlos.