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

["Lee, Yiu" <[e-mail]>]

Hi Stig,

Right. I explain only one use case. Other may find the latter case is more
attractive for their deployments. This address format should enable the
dynamic use case as well.

Yiu

On 5/14/12 4:56 PM, "Stig Venaas" <[e-mail]> wrote:

>On 5/14/2012 1:50 PM, Lee, Yiu wrote:
>> Hi Brian,
>>
>> Sorry for getting back late. I read Bert's answers to your questions.
>>His
>> answers are inline with my answers. Most information are statically
>> configured. For example: Ch1 is statically configured to 224.1.2.3 via
>>OOB
>> mechanism. If the STB is IPv4 only, it will only use IPv4 mcast address.
>> It won't use the address format defined in this draft. In my mind, the
>> most common deployment will use the same IPv6 prefix which will be
>> statically configured in the AF.
>
>Right, so that was my main concern with the draft. Is static
>configuration like this sufficient, or are there more generic cases
>where one needs to know that it is translated from IPv4 without a
>priori configuration. The flag bit (or a well-known prefix) is only
>needed in the latter case. I know there were some scenarios where
>someone found the latter to be advantageous though.
>
>Stig
>
>>
>> Regards,
>> Yiu
>>
>>
>> On 5/10/12 2:03 PM, "Brian Haberman"<[e-mail]>  wrote:
>>
>>> 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?
>>>
>>> How is 224.1.2.3 advertised to the IPv4 IP-TV clients if the content is
>>> generated by an IPv6 source?  Does the source need to be configured to
>>> use one of these IPv4-in-IPv6 multicast addresses?
>>>
>>>> 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?
>>>
>>> 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?
>>>
>>> Regards,
>>> Brian
>