Re: WGLC: draft-ietf-nsis-nslp-natfw-16.txt

Hi,

I have reviewed that draft. I don't have any major objections to the 
document, just some miscellaneous comments and clarification requests.

Here goes:

- p.6, bullet 1: at this point in the document, it is not clear to the 
  reader what the NSIS initiator/receiver are. Propose to use simpler 
  terminology at this early phase in the intro.

- p.6, end of page: propose to clearly say wo sends which message, e.g.:

"CREATE message: send by the data sender for..."

"EXTERNAL message: used by data receiver to ..."

Related comment: why abbreviate EXTERNAL to "EXT"? 
	* None of the other message are abbreviated
	* EXTERNAL is as long a word as "RESPONSE" (both abbreviated?)

Suggest to drop the EXT-term

Related to the above the document presents over and over again that 
EXTERNAL is EXT ("EXTERNAL (EXT)") and is a bit inconsistent in when to 
use EXTERNAL and when just EXT (both used here and there).

- p.7.: s/body of the document, covers/body of the document cover/

- p.23: s/inSection/in Section/

- p.27: "if the node runs _it_ garbage collection cycle."? 

- p.27: "appropriate error of class 'Protocol error' (0x1)": 0x1 is 
  Informational, ox3 is protocol error.

- p.32: "is thus managed NSLP hop-by-hop"?

- p.41: "session created by REA."?

- p.41: "using CREATE Section 3.7.1" > "(see Section 3.7.1)"?

- p.43: "if the like to aggregate"?

- p.46, whole Section 3.7.6.1: should NR be actually DR? Including Figure 
  18?

- P.46-47, Section 3.7.6.1: I don't really get this operation at all. 
  Sounds a bit complex to have the EXT-session trigger a CREATE-session. 
  Maybe some more discussion/description is needed to open up the 
  scenario. Also, the NATFW_NONCE sounds a bit wierd, somehow. In the QoS 
  NSLP, we have the same functionality, but it is called "session binding" 
  and uses a similar object where the content is the SID of the primary 
  flow. Achieves the same thing, and you can be sure there are no 
  collisions with nonces. Does the value need to be a random value? Or 
  could you perhaps re-use the QoS NSLP object since we have common object 
  repository anyway? The concept in the QoS NSLP session binding is that 
  the secondary session is valid as long as the primary session is.

- Related to the above, p.48 (middle): if you have the "internal" 
  CREATE+NONCE session and also get the e2e CREATE session, do you run 
  both simultaneously? Or do you kill one of them? I guess you can't kill 
  the EXT-session, since you need the forwarding at the NAT? Perhaps this 
  needs some more description.

- p.49: "back to NI according [to] the situation"

- p.49: "NSLP node and the of the policy rule."?

- p.51: Do the route changes really work as you describe? This may need 
  some thinking, and probably add text to the mobility draft.

- p.51: s/and sends it/and send it/

- Whole Section 4: the text talks about error cases and mandating "MUST" 
  to send various error messages? If you must always send error messages, 
  isn't this a use case for DoS attacks? I guess some words about when to 
  send error messages would be needed (rate limiting, etc.).

- p.57 (top of page): "Further version of this memo may allow other values 
  for the 'sub_ports' field." I think suggestions like this should not be 
  in a draft going to WGLC.

- p.58-60: there are a lot of error codes. Should somewhere be written how 
  and when these are used? Some of these are quite clear, but e.g.  I 
  don't understand Permanent failures 0x03, 0x05 and 0x06. Where would 
  these be used?

- p.61, Section 4.2.7: where is this object used actually? text says 
  "possibly needed", sounds a bit wierd for a draft in WGLC. Is it needed, 
  and where/when/why? Should this be also available for IPv6?

- p.62, 3rd line: "according [to] these rules:"

- p.64, Sections 4.3.1 and 4.3.2: what are these "(O)" and "(M)"? Optional 
  and mandatory? Say it clearly.

- p.64, Section 4.3.2: point c) as use case for EXT: you lost me here? Was 
  this presented earlier? Actually, in general about EXT, should it always 
  have the proxy bit P=1? What happens if I send an EXT message towards 
  the DS with P=0? Does the EXT reach the DS? What happens then?

- p.67: "In Section 5.1 we describe [how] the ..."

- p.73: s/located to the/located at the/



Jukka