Editing Net neutrality (section)

===Content caching===
[[Cache (computing)|Content caching]] is the process by which frequently accessed contents are temporarily stored in strategic network positions (e.g., in servers close to the end-users<ref name="edgecaching_NN">{{cite web |last1=Marcus |first1=Adam |title=Nuts and Bolts: Network neutrality and edge caching |url=http://blog.pff.org/archives/2008/12/edge_caching.html |website=The Progress & Freedom Foundation |access-date=12 June 2018 |archive-date=24 February 2021 |archive-url=https://web.archive.org/web/20210224081817/http://blog.pff.org/archives/2008/12/edge_caching.html |url-status=live }}</ref>) to achieve several performance objectives. For example, caching is commonly used by ISPs to reduce [[network congestion]] and results in a superior [[quality of experience]] (QoE) perceived by the final users.

Since the storage available in cache servers is limited, caching involves a process of selecting the contents worth storing. Several [[cache algorithm]]s have been designed to perform this process which, in general, leads to storing the most popular contents. The cached contents are retrieved at a higher QoE (e.g., lower latency), and caching can be therefore considered a form of traffic differentiation.<ref name="NN_benefits_risks" /> However, caching is not generally viewed as a form of discriminatory traffic differentiation. For example, the technical writer Adam Marcus states that "accessing content from edge servers may be a bit faster for users, but nobody is being discriminated against and most content on the Internet is not latency-sensitive".<ref name="edgecaching_NN" /> In line with this statement, caching is not regulated by legal frameworks that are favourable to Net Neutrality, such as the Open Internet Order issued by the [[FCC]] in 2015. Even more so, the legitimacy of caching has never been put in doubt by opponents of Net Neutrality. On the contrary, the complexity of caching operations (e.g., extensive information processing) has been successively regarded by the FCC as one of the technical reasons why ISPs should not be considered common carriers, which legitimates the abrogation of Net Neutrality rules.<ref>{{cite web |last1=Federal Communications Commission |title=Restoring Internet Freedom – DECLARATORY RULING, REPORT AND ORDER, AND ORDER |url=https://apps.fcc.gov/edocs_public/attachmatch/DOC-347927A1.pdf |access-date=13 June 2018 |archive-date=17 May 2018 |archive-url=https://web.archive.org/web/20180517003003/https://apps.fcc.gov/edocs_public/attachmatch/DOC-347927A1.pdf |url-status=live }}</ref> Under a Net Neutrality regime, prioritization of a class of traffic with respect to another one is allowed only if several requirements are met (e.g., objectively different QoS requirements).<ref>{{cite web |last1=BEREC |title=What is traffic management and what is 'equal treatment'? |url=https://berec.europa.eu/eng/netneutrality/traffic_management/ |access-date=14 June 2018 |archive-date=14 June 2018 |archive-url=https://web.archive.org/web/20180614171517/https://berec.europa.eu/eng/netneutrality/traffic_management/ |url-status=live }}</ref> However, when it comes to caching, a selection of contents of the same class has to be performed (e.g., set of videos worth storing in cache servers). In the spirit of general deregulation with regard to caching, there is no rule that specifies how this process can be carried out in a non-discriminatory way. Nevertheless, the scientific literature considers the issue of caching as a potentially discriminatory process and provides possible guidelines to address it.<ref name="NN_2010s">{{cite journal |last1=Maillé |first1=Patrick |title=Toward a Net Neutrality Debate that Conforms to the 2010s |journal=IEEE Communications Magazine |date=2016 |volume=54 |issue=3 |pages=94–99 |doi=10.1109/MCOM.2016.7432154 |s2cid=3216065 |url=https://hal.inria.fr/hal-01127958/file/paper.pdf |access-date=19 August 2019 |archive-date=30 March 2020 |archive-url=https://web.archive.org/web/20200330232831/https://hal.inria.fr/hal-01127958/file/paper.pdf |url-status=live }}</ref> For example, a non-discriminatory caching might be performed considering the popularity of contents, or with the aim of guaranteeing the same QoE to all the users, or, alternatively, to achieve some common welfare objectives.<ref name="NN_2010s" />

As far as [[content delivery network]]s (CDNs) are concerned, the relationship between caching and Net Neutrality is even more complex. In fact, CDNs are employed to allow scalable and highly-efficient content delivery rather than to grant access to the Internet. Consequently, differently from ISPs, CDNs are entitled to charge content providers for caching their content. Therefore, although this may be regarded as a form of paid traffic prioritization, CDNs are not subject to Net Neutrality regulations and are rarely included in the debate. Despite this, it is argued by some that the Internet ecosystem has changed to such an extent that all the players involved in the content delivery can distort competition and should be therefore also included in the discussion around Net Neutrality.<ref name="NN_2010s" /> Among those, the analyst Dan Rayburn suggested that "the Open Internet Order enacted by the FCC in 2015 was myopically focussed on ISPs".<ref>{{cite web |last1=Baksh |first1=Mariam |title=Content Delivery Networks Complicate Debate Over Net Neutrality |url=https://morningconsult.com/2017/07/28/content-delivery-networks-complicate-debate-net-neutrality/ |access-date=14 June 2018 |date=28 July 2017 |archive-date=14 June 2018 |archive-url=https://web.archive.org/web/20180614144232/https://morningconsult.com/2017/07/28/content-delivery-networks-complicate-debate-net-neutrality/ |url-status=live }}</ref>