Hi guys,
I'm writing a simple NOC C++ controller that estimates the end-to-end delay
of a UDP flow in a OF network.
To make such estimation I do the following:
When the flow to be monitored is received, I install a route using the
routeinstaller component, with a pair of actions on the edge nodes of the
path (OFPP_CONTROLLER and normal forwarding on path); while for all switches
in the middle of the path I setup a normal forwarding action.
In such a way I'm able to understand when a packet enters and exits the
network, an can estimate the delay (asking also the switchrtt component to
accomodate the rtt).
When calling the routeinstaller install_route(..) function, I always get an
OF malformed packet exception. I get the same error even if running the
simple_routing component, that calls the same routeinstaller API. However
despite such error notification, I can see that the route is correctly
installed, by hand inspection of flow tables.
My problem is that once the route is installed, given the same UDP flow in
input, the system behaves in a non deterministic way:
> Sometimes I get the first packet-in notification from the first switch
in the path, and sometimes from the last.
> Sometimes the number of outgoing packets is equal to the number of
ingoing packets + 1 (weird).
> Sometimes a big set of packets is first notified by the outgoing
switch (very bad behaviour).
Any suggestions?
-Best regards-
--
Andrea Simeoni
_______________________________________________
nox-dev mailing list
nox-dev@noxrepo.org
http://noxrepo.org/mailman/listinfo/nox-dev
