Re: [pim] Minor technical change in pop-count

On 11/16/2012 10:30 AM, John William Atwood wrote:
> Stig,
>
> I agree that the disjoint specification is better.
>
> I would add two words to the proposed definition---see inline for where.
>
>    Bill
>
>
> On 11/16/2012 12:54 PM, Stig Venaas wrote:
>> During AUTH48 for draft-ietf-pim-pop-count-07.txt I realized one minor
>> technical issue that I would like to address. Since this is a technical
>> change, I would like to see if anyone in the WG has any concerns.
>>
>> We got two flags regarding tunneling defined as follows:
>>
>>        t flag:  This flag is set if there are any tunnels on the
>>           distribution tree.  If a tunnel is in the oif-list, a router
>>           should set this bit in its Join/Prune messages.  Otherwise, it
>>           propagates the bit setting from downstream joiners.
>>
>>        a flag:  This flag is set if there are any auto-tunnels on the
>>           distribution tree.  If an auto-tunnel is in the oif-list, a
>>           router should set this bit in its Join/Prune messages.
>>           Otherwise, it propagates the bit setting from downstream
>>           joiners.  An example of an auto-tunnel is a tunnel set up by
>>           the Automatic Multicast Tunneling [AMT] protocol.
>>
>> It is not clear whether the "t" flag applies to all tunnels or all
>> tunnels except auto-tunnels. Or rather, by reading the description of
>> "t" by itself it would seem obvious that it is all tunnels, but the
>> fact that there is a separate flag for auto-tunnels makes it seem more
>> reasonable that the two flags are for disjoint types of tunnels.
>>
>> I would like to change the description of "t" slightly to talk about
>> manually configured tunnels. How about this text:
>>
>>        t flag:  This flag is set if there are any manually configured
>>           tunnels on the distribution tree. This means any tunnel that
>>           is not an auto-tunnel.  If a tunnel is in the oif-list, a
>                                         ^manually configured

Great catch! I'm suggesting the below text to the RFC Editor then. We'll
wait and see for a few days if there are any objections though.

       t flag:  This flag is set if there are any manually configured
          tunnels on the distribution tree. This means any tunnel that
          is not an auto-tunnel.  If a manually configured tunnel is in
          the oif-list, a router sets this bit in its Join/Prune
          messages. Otherwise, it propagates the bit setting from
          downstream joiners.

      a flag:  This flag is set if there are any auto-tunnels on the
          distribution tree.  If an auto-tunnel is in the oif-list, a
          router sets this bit in its Join/Prune messages. Otherwise, it
          propagates the bit setting from downstream joiners.  An
          example of an auto-tunnel is a tunnel set up by the Automatic
          Multicast Tunneling [AMT] protocol.

Stig

>>           router should set this bit in its Join/Prune messages.
>>           Otherwise, it propagates the bit setting from downstream
>>           joiners.
>>
>> I hope you agree this is reasonable. There is no point in having the
>> flags overlap. If we want to check if any type of tunneling is
>> involved, we just check if either of the flags are set.
>>
>> Stig
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>