There are a quite a few tools experimenter can use to investigate the behaviour of the IP network from an end user's point of view. The proper choice of tool may help to reveal some information about the delays IP fragments experience travelling accross the network or can characterize the temporal capacity conditions or can reveal the topological structure of the network.
Trying to take advantage of the fact that Monroe nodes are connected to the network via various access technologies and network providers (we call them operators) we designed experiments, whose goals were to investigate if there are observable differences by the choice of operator.
In the measurement campaigns in layer 3 the
traceroute application was used.
traceroute program injects a sequence of IP packets in the computer network with different TTL values so as to capture hop-by-hop IP connectivity.
Besides capturing the addresses of the hops dropping the packet due to time to live expired the program also measures the round trip delay for each depth the probe sequence dictates.
Note, however, the round trip delay is a composition of several factors, including the queuing delay, the propagation delay and the processing delay.
Since the goal is to see if some differentiation can be made according to the operator the edge between the network of the operator and the Internet needs to be identified. Furthermore, within the operator network also a boundary can be defined, which we believe is highly coupled with the structure of the access configuration. The former we call the gateway the latter we call the NAT gateway.
In order to say something statistically signifficant a larger sample was our goal to collect. We achieved it by covering as many Monroe source nodes as available when doing the measurement and also by targetting more nodes.
According to the target nodes two measurement scenarios were defined:
The PlanetLab is a network of computational resources shared accross the Internet operated mostly by universities and with an academic userbase.
In the popular sites case the top 1000 most frequently visited domains are used as targets. CITATION IS MISSING
In this study we collect our findings for the popular sites case.
Based on the IP address sequence the
traceroute collects towards a given target the NAT gateway is defined as the first IP address in the public dimain that fulfill the following requirements all.
The IP address of the preceeding hop has to be a private address.
Those measurements, where the preceeding hop denies telling their IP addresses are dropped, because we cannot be sure wheter that hop is still in the access LAN or the NAT gateway itself.
Offline after the measurement logs are collected we resolve the autonomous systems (AS) the IP address belong to and keep only those measurements where the resolved AS is in line with the operator of choice.
After careful filtering of data we look at
Follow these links to check out the results of April 2018 measurements:
To investigate data processing visit this notebook.