Hi Paulo, when the IETF ALTO working group started some 12 years ago, there was the expectation (or assumption) that in the P2P use case, this win-win-situation (better performance in the overlay, less resource utilization in the underlying infrastructure) would happen on its own. The core business of IETF is to standardize protocols to ensure interoperability between different implementations. Other parts of the overall P2P traffic optimization problem were not in our main focus, such as developing and fine-tuning a peer selection algorithm that would make use of the ALTO information, or mechanisms to punish misbehaving peers. Back in 2008, it was not uncommon that ISPs would throttle the bandwidth for residential customers that exceeded a certain threshold of data volume per month. This scheme could be modified from just counting bytes to multiplying each byte with its respective routing cost. Following the ALTO advice would have been a strategy for users to avoid throttling.
It should also be noted, that while the work on the protocol went on, the focus with respect to use cases shifted - from the "unmanaged" P2P networks (where no single entity is legally responsible for the overall operation and traffic distribution in the overlay) to more managed overlays such as content delivery networks (CDN) or big data applications for science (there, there might be someone to call if the overlay does the opposite of what the ALTO server suggests to do). best regards, Sebastian On Fri, Jul 03, 2020 at 08:25:04AM +0000, Paulo Edgar Mendes Caldas wrote: > Good morning, > > I am currently doing investigative work regarding the ALTO protocol for my > master's degree. I've been getting acquainted with the ALTO protocol and the > problems it tries to solve via reading of the RFCs and drafts that have been > published, but I've struggled to find a question to the following - does the > ALTO system as a whole have a plan on how to guarantee that the clients act > in good faith with the information they receive? > > In particular, consider that a P2P application wishes to have ALTO guidance > to pick between a number of potential number of peers, and thus queries for a > multi-cost map for the pairs (source_pid, destination_pid) whose throughput > and one-way-delay values are within a certain criteria. Is there anything > preventing said client to then not prefer the pair whose routing cost is > lowest? It would make sense that the ALTO server would prefer that the client > would "be kind" and cooperate with the ISP and use the information in a way > that is mutually beneficial, but what if the client only cares about client > performance? > > I can only imagine one of the following solutions - there being some > incentive mechanism, restricting the information to trustworthy partners, or > deliberately manipulating non-routing-cost metric values to steer clients > into a certain choice. The latter seems problematic as it breaks the > transparency in layer cooperation and might damage the entire reason the > system was created to begin with. > > Is there any work done in regards to ensuring client cooperative behavior? > > Kind regards, > > Paulo Caldas > _______________________________________________ > alto mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/alto _______________________________________________ alto mailing list [email protected] https://www.ietf.org/mailman/listinfo/alto
