Hi All,
I am using the IBR-DTN to demonstrate simple file transfer in my experiments.
Setup: A cross section of my network looks like this:
Opportunistic contact Opportunistic contact NodeB<--------------------------------------->NodeU<---------------------------------------->NodeG
NodeU moves between NodeB and NodeG to make opportunistic contact. For each contact NodeU pauses for 5-10 seconds.
I have configured prophet with the following parameters in all three nodes.
### prophet configuration ### #prophet_p_encounter_max = 0.8 #affects how strong the predictability is #increased on an encounter prophet_p_encounter_first = 0.7 #the predictability of a neighbor on the #first encounter prophet_p_first_threshold = 0.1 #lowest predictability when neighbors #predictabilities are forgotten prophet_beta = 0.9 #Weight of the transitive property prophet_gamma = 0.999 #Determines how quickly predictabilities #age #prophet_delta = 0.01 #(1-delta) is the maximum predictability prophet_time_unit = 1 #time unit in seconds prophet_i_typ = 120 #typical time interval between two node #encounters #prophet_next_exchange_timeout = 120 #timeout how often handshakes should be #executed prophet_forwarding_strategy = GRTR #The forwarding strategy used GRTR | GTMX #prophet_gtmx_nf_max = 30 #Maximum times to forward in the GTMX #strategy
For each node contact, I expect that the predictability map will be exchanged via call to the dtn://NodeName.dtn/routing service, and bundles will be transferred suitably.
Problem: * For many contacts (given the above mobility assumptions), NodeU does not seem to discover NodeB/NodeG. I assume that discovery has happened, if I see a "New node available" string in the log file. * Even for contacts where NodeU seems to have discovered the other node, Predictability map does not seem to be exchanged. A partial log file has been attached, where NodeU seems to have discovered NodeG (at the first beacon exchange itself), but they do not seem to exchange their predictability maps.
Am I configuring anything wrong with respect to prophet ? Also, I see a "summary vector of <node eid> is expired" in log every 60 seconds for some nodes. Please help.
I have attached the following: a) ibrdtn config file for NodeB; b) ibrdtn config files for NodeG and NodeU (same file); c) Portion of NodeU.log