Re: [pcp] UNSUPP_FAMILY error code

[<[e-mail]>]

Simon, 

I disagree.

The client does not know in advance the capabilities of the PCP-controlled devices. A client does not know what type(s) of address(es) it will need to establish communications with remotes peers (e.g., application using referrals). A client may gather all external addresses/ports from pcp servers it is aware of, and signal them to remote peers.

Unlike MAP4/MAP6, the server receiving a MAP request is not obliged to return an IP address following the indication included in the suggested external IP address field. It will try to best accommodate it, but if not, it would be fine if it returns another AF address; then it is up to the client to make use of it or not. 

In another words: we should not use Suggested IP Address as PREFER_AF option ;-)

Cheers,
Med


>-----Message d'origine-----
>De : Simon Perreault [mailto:[e-mail]]
>Envoyé : jeudi 30 mai 2013 11:53
>À : BOUCADAIR Mohamed OLNC/OLN
>Cc : Stuart Cheshire; [e-mail]
>Objet : Re: [pcp] UNSUPP_FAMILY error code
>
>Le 2013-05-30 08:32, [e-mail] a écrit :
>> The behavior you are proposing here recalls me what we had in earlier
>versions of the pcp specification (version 00 to version 03, PINxy OpCodes)
>and (version 04 to version 13, MAP4 and MAP6 OpCodes). The consensus of the
>wg was to remove that design.
>>
>> This particular text in your proposal:
>>
>>>    Note that while the specific address placed in the Suggested External
>>>    Address field is merely a suggestion that the PCP server is free to
>>>    ignore, the address family is not.
>>
>> is clearly a revival of the MAPx/PEERx opcides.
>
>This is not quite right. MAPx/PEERx were transformed into MAP/PEER
>precisely because the external address type, which was encoded in the
>opcode, is now encoded in the suggested external address field. The
>semantics have not changed. Only the syntax has.
>
>Simon
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