Re: Request for clarification - Flute - flag (B)

  Hi Vincent

Thanks for this answer but let's me ask a last clarification.

    * When B is set to 1, is it possible during these few potential
      additional packets that a sender changes B back to 0.
    * In other words, can a sender change his mind during the few
      additional packet and changes B value to 0 in order to keep on the
      transmission.
    * Would such server be considered as compliant?


And if the answer is positive, what should be the terminal behavior ?

    * Restart from scratch the download,
    * keep on the download,
    * or others


Thanks again and best regards

Cedric.


Le 19/10/2010 15:37, Vincent Roca a écrit :
> Hello Cedric,
>
> From RFC 5651 (LCT revised, p. 15), it is said:
> ---
> Close Object flag (B): 1 bit
>
>       Normally, B is set to 0.  The sender MAY set B to 1 when
>       termination of transmission of packets for an object is imminent.
>       If the TOI field is in use and B is set to 1, then termination of
>       transmission for the object identified by the TOI field is
>       imminent.  If the TOI field is not in use and B is set to 1, then
>       termination of transmission for the one object in the session
>       identified by out-of-band information is imminent.  B MAY be set
>       to 1 in just the last packet transmitted for the object, or B MAY
>       be set to 1 in the last few seconds that packets are transmitted
>       for the object.  Once the sender sets B to 1 in one packet for a
>       particular object, the sender SHOULD set B to 1 in all subsequent
>       packets for the object until termination of transmission of
>       packets for the object.  A received packet with B set to 1
>       indicates to a receiver that the sender will immediately stop
>       sending packets for the object.  When a receiver receives a packet
>       with B set to 1, then it SHOULD assume that no more packets will
>       be sent for the object to the session.
> ---
>
> There is no ambiguity IMHO. Upon receiving a packet with
> the B flag set, the receiver SHOULD assume that transmission
> of packets for this object stops, even if in practice a few
> additional packets MAY arrive. Specific recovery mechanisms
> (e.g. point-to-point recovery) can be launched at this point if
> needed, but that's out to scope of ALC and RMT documents...
> This is also the way it is implemented in our FLUTE/ALC
> software.
>
> Cheers,
>
>   Vincent
>
>
> Le 14/10/10 19:06, Cedric Thienot a écrit :
>> Dear flute experts,
>>
>> we would like to have your advice on the interpretation of the usage 
>> of the
>> Close Object flag (B) specified in the RFC 3450 (page 18).
>> On our interpretation when this flag is set to 1 by the transmitter, 
>> the receiver
>> should assume that no more packets for this object will be 
>> broadcasted in the future?
>> Therefore, the receiver can stop the reception.
>>
>>
>> Thanks,
>> Best regards
>>
>> Cedric Thienot
>>
>> www.expway.com
>>
>>
>> _______________________________________________
>> Rmt mailing list
>> [email protected]
>> https://www.ietf.org/mailman/listinfo/rmt

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