Re: [6tisch] 6P and Sf0 issue: Token to identify transactions in 6P

Hello Diego,

For the Token to identify the transaction, personally, if *the idea is to
identify a request and a response with a token*,  it can be replaced by
implementing a status machine, in which the status is able to identify the
status of 6P transaction.

Here is a rough example which is able to explain how Status Machine works:

*Initially* the status of 6P can be set as 6P_IDLE.

*For a mote sending 6p request:*

   1.  after the 6p request is ready to be sent which contains the
   candidate cell, the status turns to 6P_REQUEST_INIT
   2. after the request is sent, the status turns to
   6P_REQUEST_WAITING_RESPONSE
   3. after received the response from parent, mote sends ACK back and
   add/delete cell in schedule. The status turns to 6P_IDLE

*For a mote received 6p request:*

   1. after receiving the 6p request, the mote turns status to
   6P_RECEIVED_REQUEST
   2. when cells are selected or no cell is available, set status to
   6P_RESPONSE_TOBESENT
   3. after sending the response and get the ACK, mote will add/delete
   cells in schedule and set status back to 6P_IDLE

If the mote will not process the next 6P request if the status is correct.
Even if there are some issue that the mote stuck at one status, the timeout
will reset the status to 6P_IDLE.

With this, one byte can be save, though it's not that much.
What do you think?

Tengfei

On Thu, Mar 3, 2016 at 4:30 PM, Prof. Diego Dujovne <
diego.dujovne@mail.udp.cl> wrote:

> Dear all,
>             In order to continue the discussion we left
> unfinished at the Interim meeting in March 26th, I
> will open a number of threads to take action on several
> pending issues for the drafts:
>
> draft-wang-6tisch-6top-sublayer-04 (which will be renamed to 6top-protocol)
> draft-dujovne-6tisch-6top-sf0-00
>
> - Regarding the use of a Token to identify transactions on
> the 6top protocol, there was a proposal on the call to add
> an 8-bit field to the packet header.
>
> Do you agree with this solution?
>
> Regards,
>
>                               Diego Dujovne
>
> --
> DIEGO DUJOVNE
> Académico Escuela de Ingeniería en Informática y Telecomunicaciones
> Facultad de Ingeniería UDP
> www.ingenieria.udp.cl
> (56 2) 676 8125
>
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