Re: [Roll] [roll] #165 (applicability-home-building): DIO max interval

[peter van der Stok <[e-mail]>]

Hi Yvonne,

In RFC 6206 (trickle), the introduction explains:
  "When a node's data does not agree with its
    neighbors, that node communicates quickly to resolve the
    inconsistency (e.g., in milliseconds).  When nodes agree, they slow
    their communication rate exponentially, such that nodes send packets
    very infrequently (e.g., a few packets per hour)."

We propose to add the following text to section 4.3.1.

When a node sends a changed DIO, this is an inconsistency and forces the 
receiving node to respond within Imin.
So when something happens which affects the DIO, the change is ideally 
communicated to a node n hops away within n times Imin.
Often, dependent on the node density, packets are lost, or not sent, 
leading to larger delays.
In general we can expect that DIO changes to propagate within 1 to 3 
seconds within the envisaged networks.

When nothing happens, the DIO sending interval increases to 4.37 
minutes, thus drastically reducing the network load.

When a node does not receive DIO messages during more than 10 minutes it 
can safely conclude the connection with other nodes has been lost.

Peter

roll issue tracker schreef op 2014-11-10 23:12:
> #165: DIO max interval
> 
>  Yvonne-Anne Pignolet:
>  Please state why a value of DIO max interval of 4.37min (16ms x
>  2^14) is appropriate, it seems like a much smaller value would be
>  suitable for this usecase
> 
>  Peter van der Stok:
>  I don't understand the issue here. When something happens the 16 ms 
> come
>  into play. Assuming a limited number of hops, the change propagates 
> quite
>  timely.
>  When nothing happens, sending a reminder every 4 minutes seems quite
>  reasonable. (we are discussing propagation of network changes, not 
> user
>  commands)
> 
>  Yvonne-Anne Pignolet:
>  Until it is noticed that some happened a long time may pass because of 
> the
>  low DIO frequencey