Subject: [Roll] Traffic aware OF -03 review

From: Rahul Arvind Jadhav <[email-masked]>
Date: Tue, 6 Nov 2018 12:21:25 +0000

Hello Authors-of-TAOF,

Network lifetime is a known problem in the space and I am glad to see something been done in the context. Following are some thoughts I have:

1.       Handling Config: DIO may need to carry OF configuration parameters .. i.e. all the nodes need to agree on the unit for e.g. for THROUGHPUT_PERIOD defined in the draft. It is necessary that all the nodes agree on the time unit.

During ROLL session, Pascal mentioned that parent oscillations should be avoided and suggested use of multiple parents while the transition is in progress. Another way to handle this is to involve hysteresis in this draft and give guidelines/recommendations for configuring thresholds.

2.       Certain deployments have roughly similar data stream generated from all nodes .. for e.g. metering.. Current draft requires throughtput measurement on 6LRs .. In all cases this throughput calc may not be required .. But there is still a case to balance the network nonetheless .. Is it possible to consider balancing based on the sub-dodag size rooted at 6lr (naturally works only for storing MOP) ? In this sense, the work qasem-load-balancing was trying to do was similar considering nodes have similar traffic patterns.

3.       Section 6: There are several bits that needs to be defined in context for every routing metric (as per 6551) .. These are P, C, O, R, A bits. It is better you clarify the bits in RT context. I am specifically interested in understanding in how to handle this metric at multiple hops. How to do additive RT metric?

4.       I don't understand why enrollment aspect was brought (this was not present in earlier draft) .. The relay chosen during enrollment and parent chosen during routing could be different. Enrollment can choose a different set of metrics from routing.. Enrollment of nodes happens few times during the lifetime of the device. The metrics enrollment could consider could be completely different from routing metrics.

Regards,
Rahul