Hi Omprakash, Thanks for the quick reply.
Viable path - I see the node lost behaviour even with nodes that are directly connected(no hop, very close) to the root node. Do you mean something else by viable path ? How much traffic amounts to saturation of the channel ? I have 10 nodes having MHO code sending a packet every 5 sec, i think this should make very less traffic ? If i put tests/TestNetwork on all the nodes, to see the debug messages, i have to enable a flag or these are simply printf statements ? Right now, I have only root node connected to the PC, but as you suggested, to check the debug messages,i can connect other nodes too. Will try this. Regards, G On Wed, Jun 25, 2008 at 4:40 PM, Omprakash Gnawali <[EMAIL PROTECTED]> wrote: > On Wed, Jun 25, 2008 at 7:09 AM, Gaurav Chandwani > <[EMAIL PROTECTED]> wrote: >> Hi All, >> > ... >> I saw a strange behaviour using SerialForwarder - When the application >> is running for some hours, sometimes, i dont receive messages from a >> particular node for some minutes and then it comes back again. Its >> reproduced many times. >> >> Has anybody seen this kind of behaviour ? >> Since MHO is stable, so there should be a problem at my end but I am >> not able to find where. > > If there is no viable path between the nodes and the root, CTP won't > be able to deliver packets. Have you considered that possibility? > >> Since the nodes can reach root node directly, they will send message >> only to it or also other nodes ? > > It can be either way depending on the link and path qualities. > >> Can there be a problem with root node sending of messages on UART or >> some other queue overflow ? I am using baud rate of 115200. >> Next, I will try to use printf to understand at which level the problem is. > > Queues should not overflow if you are not sending a lot of packets and > if there are viable paths. It is possible to overflow a queue if a > node is not able to drain it fast enough (too many retransmissions, > for example) > >> As i read, the reliability of CTP should be 99.9% at low traffic rate, >> but the 0.1% messages that are lost, are lost >> periodically or there is a possibility that they can be lost in chunks >> of messages ? and what will be high traffic rate ? > > If you are planning to saturate the channel, you should expect a lot of > losses. > > If these motes are connected with a PC during the experiment, I > suggest running tests/TestNetwork and looking at the debug messages > logged by each mote to understand the cause for the loss you are > seeing. > > - om_p > -- --------------------------------------------------------------------------------------------------------------------- To accomplish great things, we must not only act, but also dream; not only plan, but also believe. - Anatole France _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
