[6tisch] [6TiSCH] return code in 6p response defined in sixtop draft

[Tengfei Chang <[e-mail]>]

Dear all,


I have some question about the return code (mainly about the ERROR code) in
6p response packet define in the draft:
https://tools.ietf.org/html/draft-ietf-6tisch-6top-protocol-02

In figure 7:
https://tools.ietf.org/html/draft-ietf-6tisch-6top-protocol-02#section-4.2.4

 Return Code              Value          Description
   +--------------+------------------------+---------------------------+
   | RC_SUCCESS   | IANA_6TOP_RC_SUCCESS   | operation succeeded       |
   +--------------+------------------------+---------------------------+
   | RC_ERR_VER   | IANA_6TOP_RC_ERR_VER   | unsupported 6P version    |
   +--------------+------------------------+---------------------------+
   | RC_ERR_SFID  | IANA_6TOP_RC_ERR_SFID  | unsupported SFID          |
   +--------------+------------------------+---------------------------+
   | RC_ERR_GEN   | IANA_6TOP_RC_ERR_GEN   | schedule generation error |
   +--------------+------------------------+---------------------------+
   | RC_ERR_BUSY  | IANA_6TOP_RC_ERR_BUSY  | handling previous request |
   +--------------+------------------------+---------------------------+
   | RC_ERR_NORES | IANA_6TOP_RC_ERR_NORES | not enough resources      |
   +--------------+------------------------+---------------------------+
   | RC_ERR_RESET | IANA_6TOP_RC_ERR_RESET | abort 6P Transaction      |
   +--------------+------------------------+---------------------------+
   | RC_ERR       | IANA_6TOP_RC_ERR       | generic error             |
   +--------------+------------------------+---------------------------+
   | reserved     | TODO-0xf               |                           |
   +--------------+------------------------+---------------------------+


As it defined a lots of error return code and also it has generic error:
RC_ERR.


   - When should the nodes use the generic RC_ERROR? I assume it indicates
   the request cells are not available (the cell is occupied already when
   adding OR can't find the cell when deleting)?
   - Also, if the 6p response has multiple cases matched (for example, the
   candidate cells are occupied RC_ERROR and also no enough resource
   ERROR_NORES...), which one should the mote choose? (add priority for the
   error code? at least we need a decision)


Looking forward to talk to you during the meeting soon!

Tengfei

-- 
Chang Tengfei,
Pre-Postdoctoral Research Engineer, Inria