Knowing network performance characteristics is vital to the success of global communications. The challenge is obtaining accurate and current information--and this is especially difficult as companies increasingly rely on the Internet as their "corporate backbone." The focus of this article is to share the details of an ambitious project that is attempting to map the topology and performance of the Internet.
In November 2010, the RIPE NCC (Reseaux IP European Network Coordination Center) launched a project called Atlas. RIPE is to Europe what ARIN (American Registry for Internet Numbers) is to the US and Canada: it is one of the world’s five regional Internet registries. Atlas is a measurement system that consists of distributed probes that can be implemented by anyone that requests one from RIPE's website. Anyone that hosts a probe is considered to be a volunteer. The data collected by the probes is rolled up into a master "atlas" of Internet information that is made available in a condensed form to the public and in a more detailed form to researchers and volunteers.
Since RIPE is based in the Netherlands, it comes as no surprise that the majority of the currently installed probes reside in Europe. To date there are approximately 1,500 probes worldwide, of which only 85 are installed and registered in the US. RIPE's goal is to scale up the number of probes into the tens of thousands by encouraging worldwide participation. RIPE does not discriminate on where a probe gets installed. I currently have one installed in my home office, but it could be easily installed in an enterprise network, government office, college campus, or at a local Starbucks. The success of the Atlas project hinges on its ability to get as many probes installed as possible in as many locations as possible. The following is a diagram of the current distribution of probes.
Click here for larger map
Each triangle represents an installed probe; the color coding indicates whether the probe is up (green) or down (red). Additional maps are accessible at https://atlas.ripe.net/contrib/maps_index.html.
A probe is a small, USB-powered device with a single RJ-45 Ethernet connection. The minimum requirements to get a probe up and running are that it needs to plug into any open Ethernet port located either on the ISP router, a hub, or switch; access to a DHCP and DNS server (which are contained in virtually all ISP-provided home routers); and the ability to communicate out to the Internet on TCP port 443 and to send and receive ICMP traffic (again, something all consumer-grade Internet connections provide). ICMP traffic is the basis for the test measurements that are conducted on a continual basis. Outgoing TCP port 443 is used to connect to RIPE's web server in order to upload the results of the measurement tests.
Once a probe becomes operational and is registered on the RIPE network, it immediately connects to RIPE's network and starts running a set of preconfigured tests to preconfigured destinations. At this time, measurement tests consist of PING, Traceroute, and DNS queries to all of the Internet's DNS root servers. In addition, users have the ability to define a limited number of user-defined measurements called UDMs.
Every probe conducts a series of tests which include:
* Total uptime
* RTT (round-trip time) measurements to a set preconfigured destinations
* RTT measurements to the first and second hops leaving the local network
* Traceroute measurements to a set of preconfigured destinations
* DNS queries to the DNS root servers
It is anticipated that over time a richer set of tests will be developed that will allow for greater flexibility to what destinations can be tested and the types of measurement tests that can be performed. However, RIPE's stated goal is not to move up the application stack. Instead the project will remain a way of mapping Internet presence around the globe and understanding the performance characteristics between sites around the world.
The Atlas project, which is still in the prototype stage, holds a lot of promise. Much work needs to be done to improve the user interface, and it remains to be seen how effectively the collected data can be leveraged. The key to the Atlas project's eventual success, however, will be determined by how well it is embraced and adopted by the global network community. If successful, the project could become an indispensable source of Internet performance data.
Additional information about the RIPE Atlas project can be found at http://atlas.ripe.net. I encourage you to check it out, spread the word, and sign up to become a volunteer.
