User login

Stephen Eichler's blog

25

May

2015

Carried out validation on the trace based simulators and the IS0 simulator. The parts completed have been written into my thesis.

The validation programs for IS0 needed to be updated because of the extra terms that I have included in the analysis. These are sources windows and maximum destinations per AS. Sources windows are groupings of source addresses which are analysed at the same time, before analysing the next group. Limiting the number of destinations per AS makes the analysis a manageable size and maximises spread of analysis across the Internet.

20

May

2015

Further additions have been made to the chapters on trace based Doubletree and Megatree. Preparation for this involved carrying out validation on the simulators. This involved ensuring that each trace was processed once. There were also dumps of small numbers of traces to ensure that the algorithm used behaved correctly.

The packet event based simulator IS0 is also being validated. Some errors have occurred and investigation is underway to determine the causes of these.

11

May

2015

I have been monitoring the latest black hole detector run on PlanetLab.

More changes based on Richards criticisms, to my thesis have been made. In particular I have added structure to the background chapter. This included finding some references relevant to the search for non 5-tuple fields that cause load balancing to occur. I found one paper that said they would look into this area in the future, thus helping to justify the research area.

04

May

2015

Now that the per destination run is complete I started another run of black hole detector on Planetlab.

In response to the criticisms and suggestions from Richard I have been updating the background and related work chapters of my thesis.

In addition the IS0 runs, per destination and Megatree runs have resulted in updated graphs for my thesis. It is also means that I can write more in the results and discussion sections for these chapters.

01

May

2015

The new runs on IS0 were completed and the data were used to create graphs for my thesis. The new runs were mostly controls for the sources windows data and Traceroute and Doubletree from few sources. This latter is included simply to show results from the simulator in its native state, as a starting point for this research.

The latest runs on the Megatree simulator also completed. This was further analysis of many to few situations where each source was used at least three times. The key focus was how much extra traffic to use to find load balancers that have already been seen. Two new modes were used for this in addition to the initial standard Traceroute before MDA. These were a simple estimate of extra traffic and an analysis of previously seen diamonds with the same source node to estimate require traffic.

Further analysis of the per destination run carried out on Planetlab to count unique load balancers has been carried out. As expected the count for reduced flow IDs was lower than the full analysis, however the amount of traffic was also lower and the percentage of traces with a per destination load balancer was possible higher. This latter point possible reflects the formation of clumps in the full analysis due to per packet LBs in the diamond under investigation thus masking some diamonds out from the count. There appear to be some useful advantages to the reduced analysis if locating diamond divergence points is the question of interest.

20

Apr

2015

Code was written to analyse the new data set containing per destination data based on seven flow IDs and many. Once the data was downloaded from PlanetLab a run to count paths containing per destination load balancers for each mode was set underway.

The revised Megatree simulation completed and I found a corrupted address file causing the results to be incorrect. The simulation was based on an estimate of extra packets required by Megatree to find already analysed load balancers without carrying out a complete pre run Traceroute analysis.

Whilst waiting for these results I have been going over sections of my draft thesis to check for correctness and logical flow.

13

Apr

2015

The Internet simulator IS0 was tasked to do some strategic simulations. One of the angles is varying control packet queuing time for the sources window setting of 500. There are also a couple of control runs for some different initial TTL settings.

An attempt has been made to reduce the amount of extra probing required by the Megatree simulator. Currently a full simple Traceroute run is required to determine if a Traceroute contains a divergence convergence point pair that has been seen before. This is being reduced to do some extra probing when a previously seen divergence point is encountered in the main MDA trace.

I have printed my entire thesis draft and have started proof reading it from the beginning. This is an attempt to ensure that a well rounded story is told with good logical flow and appropriate discussion.

31

Mar

2015

An attempt has been made to polish up the Megatree data set. I few runs have been carried out with minor corrections. These have included for the stage counts, stopping the local data after the stages expire. For this it is lightly unclear whether stopping local data usage is justified, however the argument is that when the remaining traces are carried out simultaneously, local data is unavailable if it is applied after the trace in which it was collected. This could be due to the time it takes to collect and process the data to make it available.

I have also been running the IS0 Internet simulator to show optimisation of the initial TTL with the fuller data set. Another issue to consider is whether to optimise or show the affect of packet queuing delays. Perhaps this could be done for the TTL chosen as optimum using a moderate setting for packet queuing delay. The results seem to indicate that a bias for many sources towards the a small TTL really helps to make use of global stop set data when using sources windows.

Some further time is needed to get at least a few completed runs of per flow load balancer data with the few flow IDs and many collected side by side.

24

Mar

2015

It was decided to simulate an extra TTL value, using the IS0 event driven Internet simulator, to achieve a better level of optimisation of this parameter. Several runs were initiated and the data files are being collected.

Work has begun on the Megatree chapter. A description of Megatree was written and some of the appropriate graphs have been accumulated in the thesis document. Megatree avoids discovering the same load balancer more than once. When a load balancer divergence point is encountered in a new trace stored information indicates where possible convergence points might be in terms of hop count and IP address.

The collection of per destination ICMP traces is still underway. Two types are being collected at sequentially in time. They are gathered with seven or 128 flow IDs. Of interest is if they count the same number of load balancer divergence points and what amount of traffic is involved in doing that.

17

Mar

2015

Updates were carried out on the Doubletree simulator chapters. A graph of the distribution of trace lengths was generated after running warts analysis for the CAIDA download Traceroute data set. The same also needs to be done for the MDA data set that was also used for simulation.

Run on the IS0 simulator for the few to many scenario and all the levels of the stages variable was initiated and start TTL of 8. This is for comparison with the sources windows data that also used this start TTL setting. I should possibly do some more start TTL levels to get a better optimisation.

A per destination MDA cycle is running on PlanetLab. It will take two weeks and will compare the use of a small number of flow IDs with a large number. The ability to find load balancers will be compared, but not the ability to find all successors as this is already known to differ markedly.

Some minor changes were made to the Churn paper. In particular a graph was updated to be more readable.