Re: [Softwires] Unified Softwire CPE: draft-bfmk-softwire-unified-cpe

["Senthil Sivakumar (ssenthil)" <[e-mail]>]

On 12/3/12 4:55 AM, "[e-mail]"
<[e-mail]> wrote:

>Hi Ole,
>
>As a background, the usual modes supported by a CPE are: IPv4-only,
>Dual-stack. A natural mode to be added to the list is IPv6-only ... but
>this mode is not sufficient to reflect whether IPv4 service continuity
>features are enabled in the CPE or not. This draft focuses on this
>service: i.e., IPv4 service continuity when only an IPv6 prefix is
>configured to the CPE.
>
>Now for the items you listed below, I do not see them as "modes" but as a
>set of actions to be enforced based on some trigger(s). The combination
>of the actions listed below will result in a "mode".
>
>The CPE will need some trigger(s) to decide which modules are to be
>mounted (e.g., NAT, port restriction, etc.) and how some configuration
>will be enforced (e.g., IPv6@ of the local IPv4-in-IPv6 tunnel, IPv4
>address, etc.). Several cases are to be considered:
>
>(1) a CPE is complied to support only one mode: no issue here.
>(2) a CPE supports several modes but only one mode is explicitly
>configured: once a mode is enabled, the behaviour of the CPE is similar
>to (1)
>(3) the CPE supports several modes but no mode is explicitly enabled: the
>CPE will need additional triggers to decide which mode to activate (e.g.,
>If only a Remote IPv4-in-IPv6 Tunnel Endpoint is configured, this means
>the stateful mode must be enabled). A mode is defined as a set of actions
>(mount a module, configuration actions).

To make this list complete,
#4 should be CPE supports several modes and several modes are configured.

Thanks
Senthil
>
>The list of actions you provided needs to be captured somehow in the
>draft. I will double check the text and see whether any item is missing
>in -00.
>
>Thanks. 
>
>Cheers,
>Med
> 
>
>>-----Message d'origine-----
>>De : Ole Trøan [mailto:[e-mail]]
>>Envoyé : vendredi 30 novembre 2012 20:36
>>À : BOUCADAIR Mohamed OLNC/OLN
>>Cc : Simon Perreault; [e-mail]
>>Objet : Re: [Softwires] Unified Softwire CPE:
>>draft-bfmk-softwire-unified-cpe
>>
>>Med, et al,
>>
>>> Med: The rationale we adopted in this draft is as follows:
>>> 
>>> * there are three major flavors: full stateful, full
>>stateless, and binding mode
>>> * all these modes can support assigning a full or a shared
>>IPv4 address
>>
>>now you got me thinking, are these really the right modes from
>>a CPE perspective?
>>
>>let me try to explain, with my CPE implementor hat on, what
>>"modes" would make sense?
>>
>>- NAT placement. do I need a NAT on the CPE or not?
>>  (no NAT && no IPv4 address == DS-lite)
>>- full IPv4 address assigned.
>>  I can assign the IPv4 address to the tunnel endpoint
>>interface, and use that address for
>>  local applications, and as the outbound address of the NAT
>>  (mechanisms: MAP, Public 4over6)
>>- IPv4 prefix assigned:
>>  I need to disable the CPE NAT, and use the assigned IPv4
>>prefix as my LAN side DHCPv4 pool
>>  (mechanism: MAP)
>>- Shared IPv4 address.
>>  I must enable a local NAT, I cannot assign the IPv4 address
>>on the "WAN" interface, but only use it
>>  for the outbound side of the NAT.
>>
>>then there might be a sub-modes for "tunnel endpoint
>>determination" i.e. how to determine an IPv6 tunnel end point
>>address given an IPv4 destination address and port.
>>1) algorithmic (MAP)
>>2) configured (Public 4over6, LW46, DS-lite)
>>
>>and a sub-mode for IPv4 address configuration:
>>1) As "native IPv4"
>>    (Public4over6, LW46)
>>2) Embedded Address
>>    (MAP)
>>3) None
>>   DS-lite
>>
>>does this make sense?
>>
>>cheers,
>>Ole
>>
>>
>>
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