Re: Comments on draft-ietf-v6ops-ent-scenarios-00

["Eva M. Castro" <eva@gsyc.escet.urjc.es>]

 Hi,

First, thanks for this draft, I think it is very useful to analyze
and understand transition aspects. Im also agree with the idea that
defining a default transition scenario, will not work. However,
this draft helps to think about key aspects when moving to IPv6.

Some comments around this draft:

--> In table of contents:

"
3.  Base Scenarios..............................................6
3.1  Base Scenarios Defined.....................................6
3.2  Scenarios Characteristics..................................6
3.3  Base Scenario Examples.....................................8
"

I understand point 3.1 and 3.3 are very different, point 3.1 explains
transition scenarios, or IPv6 scenarios, and point 3.3 explains
existing enterprise scenarios. Maybe, it is more clear if the name
of these subsections is changed:

3.1 IPv6 transition base scenarios.
3.2 Scenarios Characteristics.
3.3 Enterprise specific scenario examples.



Tim Chown wrote:

> > 3.1  Base Scenarios Defined
> >
> >   Scenario 1: Enterprise with an existing IPv4 network wants to deploy
> >               IPv6 in parallel with their IPv4 network.
> >
> > **Note To V6ops WG: Would a network topology map be useful here?
> >    
>
> I don't think such a map is necessary for any of the base scenarios.
>
> However, by "in parallel" do you mean dual-stack infrastructure or separate 
> infrastructure, or is that irrelevant?
>  

--> If it was not dual-stack infrastructure, I think it would be
scenario 3. If this scenario is related to dual-stack, maybe it could
be named dual-network.


> >     Assumptions: The IPv4 characteristics have an equivalent in
> >                  IPv6.    
>
> Where might they not do?
--> Maybe scenario 2, only some specific IPv6 applications should work,
so not all IPv4 services are required in the IPv6 network.


> >   Scenario 3: Enterprise deploying a new network or re-structuring an
> >               existing network, decides IPv6 is the basis for network
> >               communication.
> >    
>
> Does this mean IPv6-only network infrastructure?   Remember you have defined
> IPv6 above as equal to IPv6-only, so is that what you mean here?
--> I suppose this scenario is an IPv4 and IPv6 heterogeneous network which
will converge to an IPv6 network, where an IPv4 and IPv6 heterogeneous
network is a set of network zones, IPv4-only, IPv6-only and dual stack.

> >     Assumptions: Required IPv6 network components are available, or
> >                  available over some defined timeline.
> >    
>
> Again, do you really mean IPv6-only, or IPv6-capable?
>  
--> I understand every kind of node, without loosing  IPv4/IPv6
interoperability. Not sure if it is required to emphasize the different
kind of nodes in this scope.

> >     Requirements: Interoperation and Coexistence with IPv4 network
> >                   operations and applications are required for
> >                   communications.
> >    
>
> So is scenario 3 an IPv6-only network into which IPv6-only or dual-stack
> hosts may be deployed?  If so maybe state that 3 paragraphs up.
--> I thought scenario 3 was an IPv4 and IPv6 heterogeneous network, since
dual-stack network was scenario 1.

> >   Characteristic 1 - Providers for External Network Operation
> >   - IPv4 existing address ownership (Provider based addresses vs.
> >     Provider independent addresses)?
> >    
>
> And number of globally routable IPv4 addresses available?
--> Very important for some transition mechanisms which require a
pool of routable IPv4 addresses.

> >   The Enterprise network will have to support the coexistence of IPv6
> >   and IPv4, to support legacy IPv4 applications and nodes. The
> >   Enterprise user has the following choices for that coexistence to
> >   consider today.
> >    
>
> Does this mean "of IPv6-only and IPv4-only"?  This is what is implied by
> the definition of terms at the start of the document.  Do we actually mean
> "IPv6-capable and IPv4-capable" or, in the language of the definitions, 
> "IPv6, IPv4 and IPv4/IPv6" applications and nodes?
--> In my opinion, coexistence means interoperability between every kind
of node and application that enterprise requires. Again, not sure if the
different kind of nodes and applications should be distinguished in this
scope.


--> Section 4 is named "Support for Legacy IPv4 Nodes and Applications"
however applications are not mentioned in this section. So, maybe it should
be named "Support for Legacy IPv4 Nodes".


--> maybe  4.1 and 4.2 cases could be more general if they are 
considered as:

4.1. Communicating IPv4 networks through IPv6 zone
4.2. Communicating IPv6 networks through IPv4 zone.

These two cases include that end-point nodes are dual stack or single stack
and tunnels can be started from end-point nodes (dual stack) or from
intermediate router (end point nodes are single stack). Besides, I think
it is more coherent with the name of the subsection 4.3, "IPv6 
communication
with IPv4" which is about connecting networks, not nodes.

Regards,

eva

--
Eva M. Castro <eva@gsyc.escet.urjc.es>