Hello Omprakash :
I have some questions about the interface CtpInfo .
Firstly , i am puzzled to the meaning of some fields in routetable.
in the structure routing_table_entry (TreeRouting.h), there are some
information of the current node . the field of parent in route_info_t should
be the parent of one neighbor in the routetable , and what does the ETX mean
? is it the the neighbor's parent's EXT or the neighbor's the ETX ?(the EXT
here should be the path metric to the root??) .
i have seen the implementation of CtpInfo in CtpRoutingEngineP, and i have
interest to the command which get the neighbors' information.
command uint16_t CtpInfo.getNeighborLinkQuality(uint8_t n) {
return (n < routingTableActive)? call
LinkEstimator.getLinkQuality(routingTable[n].neighbor):0xffff;
}
command uint16_t CtpInfo.getNeighborRouteQuality(uint8_t n) {
return (n < routingTableActive)? call
LinkEstimator.getLinkQuality(routingTable[n].neighbor) +
routingTable[n].info.etx:0xfffff;
}
in my opinion , the command of getNeighborLinkQuality returns a value of the
quality between the current node and this neighbor in the routetable .
if the field of ETX in route_info_t is the neighbor's EXT to the root , i
think the command getNeighborRouteQuality returns a value of path metric
between the current node and the root node through this neighbor (which is
the sum of this neighbor's ETX to the root and the quility between the
current node and the neighbor node).
the command Ctp.getEtx(uint16_t* etx) will return the value of the path
metric between the current node and the root through the node's parent. i
find there are some differencs with the way in
CtpInfo.getNeighborRouteQuality.
*etx = routeInfo.etx + evaluateEtx(call
LinkEstimator.getLinkQuality(routeInfo.parent));
and the function evaluateEtx() is
uint16_t evaluateEtx(uint16_t quality) {
return (quality + 10);
}
i don't know whether i have expressed the problem distinctly , i think the
two ways have the difference of "10" . am i right ,Omprakash ? can you give
me an explain?
--
zhang jiwen
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