RE: [MBONED] APPSDIR review of draft-ietf-mboned-64-multicast-address-format-01

[<[e-mail]>]

Dear Brian,

Please see inline.

Cheers,
Med 

>-----Message d'origine-----
>De : Brian Haberman [mailto:[e-mail]] 
>Envoyé : jeudi 10 mai 2012 20:03
>À : Lee, Yiu
>Cc : Carsten Bormann; BOUCADAIR Mohamed OLNC/NAD/TIP; 
>[e-mail]; [e-mail]; The IESG; 
>[e-mail] application-layer protocols; 
>[e-mail]
>Objet : Re: [MBONED] APPSDIR review of 
>draft-ietf-mboned-64-multicast-address-format-01
>
>Hi Yiu,
>      Let me ask a few questions...
>
>On 5/9/12 10:52 PM, Lee, Yiu wrote:
>> Hi Carsten,
>>
>> Thanks very much for reviewing the document. I just want to 
>add a point to
>> your question about how applications decide when to use this 
>multicast
>> address format. In fact, they don't. Imagine a use case 
>where a legacy
>> IPv4 IP-TV receiver (an app) wants to join a channel which 
>is broadcasted
>> in IPv6. The app will continue to send the igmp-join (say 224.1.2.3).
>
>How does the IPv4 IP-TV know to join 224.1.2.3?

Med: For this particular case (i.e., IPv4-only receiver over an IPv6 network+IPv4 source), the same discovery mechanism as for an IPv4-only network will be used. 

>
>How is 224.1.2.3 advertised to the IPv4 IP-TV clients if the 
>content is 
>generated by an IPv6 source? 

Med: The source is IPv4 but the IPv4-enabled receiver is connected to an IPv6-only network (e.g., http://tools.ietf.org/html/draft-ietf-softwire-dslite-multicast-02#section-4).

 Does the source need to be configured to 
>use one of these IPv4-in-IPv6 multicast addresses?

Med: This address is an address representing the IPv4 source in an IPv6 network. The source is not required to be aware of that address.

>
>> There will be a function in the network which is statically 
>configured
>> that when it receives a igmp-join, it would covert to a corresponding
>> mld-join. The IPv6 address in the join message will follow what is
>> described in this draft. This Adaptive Function is transparent to the
>> application and managed by the network.
>
>Are you limiting this approach to only mapping at the IGMP/MLD 
>protocols?

Med: No. If the receiver is IPv6-enabled, it can build an IPv4-embedded IPv6 address if it has been configured with an MPREFIX64.

>
>How does your Adaptive Function know which IPv6 multicast 
>prefix to use 
>when mapping the IPv4 multicast address in the IGMP Report 
>message to MLD?

Med: By configuration. Please refer to Section 6 of address format draft or http://tools.ietf.org/html/draft-ietf-softwire-dslite-multicast-02#section-5.


>
>Regards,
>Brian
>