Re: comments on draft-ietf-dmm-requirements-02

Hi Jouni, all,

  |  "PS2:  Divergence from other evolutionary trends in network
  |         architecture
  |
  |         Centralized mobility management can become non-optimal with a
  |         flat network architecture."
  |
  | o What are the "other"? I would consider removing PS2 if we cannot
  |name those.

I think "other" here refers to the distributed nature of delivering network services/content today (e.g. multiple data centers, CDNs etc.). It's not only the mobile that moves around these days, but your "correspondent" node as well.


  |  "PS3:  Low scalability of centralized route and mobility context
  |         maintenance"
  |
  | o Isn't e.g. the SDN evolution just doing to the opposite? Highly
  |   centralized management point for traffic steering? I would

Oh dear, should we discuss SDN scalability here? :)


  |  "REQ2:  Transparency to Upper Layers when needed
  |
  |          DMM solutions MUST provide transparent mobility support
  |above the IP layer when needed.  Such transparency is needed,
  |for.."
  |
  | o Doesn't the "when needed" make the earlier MUST conditional? At
  |least I understand it so. If that is the case we probably could just say:
  |   "DMM solutions SHOULD provide transparent mobility support above
  |the IP layer." ?

I know we should not be talking implementation, but since I got inspired just now, this is the way I parse the former:

procedure dmmXYZ (in: mobility_support_required, out: mobility_support) {
mobility_support = false;
...
if (mobility_support_required==true) then mobility_support=true;
...
}

Your proposal does not capture the conditionality of mobility support for different hosts, applications, and even different sessions of the same app. I read it more like

// set to 0 for disabling mobility support
#define MOBILITY_SUPPORT 1 

  |In Section 4.4:
  |
  |  o I would just remove the sentence:
  |    "Motivation: Using IETF protocols is easier to deploy and to
  |     update." IMHO it brings no additional clarity what has already
  |     been said.

Second this too, although the section looks a bit too short then.

Best Regards,

Kostas