[Tinyos-help] Re: Questions on CTP functioning

[Pedro Almeida]

Alright, sorry, i just read the CTP a bit better and understood this:

The routing frames are returned to a node when requested by another node by
enabling the P bit (routing pull) in the data frame.
The LEEP frames are periodical and should (i believe) be sent by default to
measure link quality on already established routes.

So let me redo the questions:

How does the P bit enabling works? Who/what causes it and why?
The question about the 14 data messages remain.

Thank you and sorry for rushing into questions without reading.

Pedro

On 7/14/07, Pedro Almeida <pedralm at gmail.com> wrote:
>
> Hello all;
>
> I have some doubts concerning the way CTP works:
>
> - when are CTP routing frames sent? and the LEEP frames?
>
> TEP 123 states: "The implementation sends routing beacons as LEEP
> packets." What does this mean?
>
> but since "The implementation uses two mechanisms to estimate the quality
> of a link: periodic LEEP [1] packets and data packets.", then why do I
> notice that only after exactly 14 data messages exchanged do I get correct
> payloads within the serial frames? it's as if the tree is still being formed
> and until then, all i get is 0'es. If i reduce the rate of data frames are
> being sent or if i increase the number of nodes, it still requires exactly
> 14 frames (at least 14 frames on the serial port) to give meaningful
> information. Are not the LEEP frames used by default? How can i relate this
> to the behaviour i see in the serial port. And the routing frames? are they
> also being exchanged by default somewhere in the link layer?
>
> Thank you!
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.millennium.berkeley.edu/pipermail/tinyos-help/attachments/20070714/89d653a0/attachment.html