Re: [6tisch] Questions on RPL Settings in RFC 8180

2018-08-27 Thread Pascal Thubert (pthubert)
Hello Yatch: I agree; thus my quote of RFC 6206 in the other mail. Now even if we do not do an erratum, an implementation should not schedule a transmission faster than it can send; iow I should be reset to Imin but rounded to the next minimal slot or the next mcast slot available. A node sh

Re: [6tisch] Questions on RPL Settings in RFC 8180

2018-08-27 Thread Yasuyuki Tanaka
Thank you, Pascal! > [PT>] True, so we never reach 9 and stay compatible with OF0. I guess the max > ETX of 3 is arbitrary, we could have gone up to 11/3... OK! That is what I understood. It's very clear now. > The initial value of I (see RFC 6206) is between Imin and Imax. With the > default,

Re: [6tisch] Questions on RPL Settings in RFC 8180

2018-08-27 Thread Pascal Thubert (pthubert)
Starting a discussion on your last point, Yatch: RFC 6206 says: " Finally, a protocol SHOULD set k and Imin such that Imin is at least two to three times as long as it takes to transmit k packets. " By default k n RPL is set to very conservative DEFAULT_DIO_REDUNDANCY_CONSTANT of 10, so th

Re: [6tisch] Questions on RPL Settings in RFC 8180

2018-08-27 Thread Pascal Thubert (pthubert)
Hello Yatch > > (1) Rank Computation > > RFC 8180 says: > > rfc8180> 5.1.1. Rank Computation > rfc8180> (...) > rfc8180> Sp SHOULD be calculated as (3*ETX)-2. The minimum value of Sp > rfc8180> (MINIMUM_STEP_OF_RANK) indicates a good quality link. The > rfc8180> maximum value of Sp (MAXIMUM_S