Editing Net neutrality (section)

===Quality of service===
{{Main|Quality of service}}
Internet routers forward packets according to the different peering and transport agreements that exist between network operators. Many internets using Internet protocols now employ quality of service (QoS), and Network Service Providers frequently enter into Service Level Agreements with each other embracing some sort of QoS. There is no single, uniform method of interconnecting networks using [[Internet Protocol|IP]], and not all networks that use IP are part of the Internet. [[IPTV]] networks are isolated from the Internet and are therefore not covered by network neutrality agreements. The IP [[datagram]] includes a 3-bit wide Precedence field and a larger [[DiffServ]] Code Point (DSCP) that are used to request a level of service, consistent with the notion that protocols in a layered architecture offer service through [[Service Access Point]]s. This field is sometimes ignored, especially if it requests a level of service outside the originating network's contract with the receiving network. It is commonly used in private networks, especially those including [[Wi-Fi]] networks where priority is enforced. While there are several ways of communicating service levels across Internet connections, such as [[Session Initiation Protocol|SIP]], [[Resource Reservation Protocol|RSVP]], [[IEEE 802.11e]], and [[MPLS]], the most common scheme combines SIP and DSCP. Router manufacturers now sell routers that have logic enabling them to route traffic for various Classes of Service at ''wire-speed''.{{citation needed|date=August 2024}}

Quality of service is sometimes taken as a measurement through certain tools to test a user's connection quality, such as Network Diagnostic Tools (NDT) and services on speedtest.net. These tools are known to be used by [[Regulatory agency|National Regulatory Authorities (NRAs)]], who use these QoS measurements as a way of detecting Net Neutrality violations. However, there are very few examples of such measurements being used in any significant way by NRAs, or in network policy for that matter. Often, these tools are used not because they fail at recording the results they are meant to record, but because said measurements are inflexible and difficult to exploit for any significant purpose. According to Ioannis Koukoutsidis, the problems with the current tools used to measure QoS stem from a lack of a standard detection methodology, a need to be able to detect various methods in which an ISP might violate Net Neutrality, and the inability to test an average measurement for a specific population of users.<ref>{{Cite journal|last=Koukoutsidis|first=Ioannis|date=2015|title=Public QoS and Net Neutrality Measurements: Current Status and Challenges Toward Exploitable Results|jstor=10.5325/jinfopoli.5.2015.0245|journal=Journal of Information Policy|volume=5|pages=245–286|doi=10.5325/jinfopoli.5.2015.0245|doi-access=free}}</ref>

With the emergence of multimedia, [[VoIP]], IPTV, and other applications that benefit from low latency, various attempts to address the inability of some private networks to limit latency have arisen, including the proposition of offering [[tiered service]] levels that would shape Internet transmissions at the network layer based on application type. These efforts are ongoing and are starting to yield results as wholesale Internet transport providers begin to amend service agreements to include service levels.<ref>{{cite news |url=http://www.lightreading.com/document.asp?doc_id=101271 |title=Carriers Seek IP QOS Peers |access-date=26 December 2008 |last=Sullivan |first=Mark |date=14 August 2006 |newspaper=Light Reading |url-status=live |archive-url=https://web.archive.org/web/20081216141744/http://www.lightreading.com/document.asp?doc_id=101271 |archive-date=16 December 2008}}</ref>

Advocates of net neutrality have proposed several methods to implement a net-neutral Internet that includes a notion of quality-of-service:
* An approach offered by Tim Berners-Lee allows discrimination between different tiers while enforcing strict neutrality of data sent at each tier: "If I pay to connect to the Net with a given quality of service, and you pay to connect to the net with the same or higher quality of service, then you and I can communicate across the net, with that quality and quantity of service."<ref name="berners-lee-def" /> "[We] each pay to connect to the Net, but no one can pay for exclusive access to me."<ref name="berners-lee-def1">{{cite web |url=http://dig.csail.mit.edu/breadcrumbs/node/132 |title=Neutrality of the Net |access-date=26 December 2008 |last=Berners-Lee |first=Tim |author-link=Tim Berners-Lee |date=2 May 2006 |website=timbl's blog |url-status=dead |archive-url=https://web.archive.org/web/20090101023106/http://dig.csail.mit.edu/breadcrumbs/node/132 |archive-date=1 January 2009}}</ref>
* United States lawmakers have introduced bills that would now allow quality of service discrimination for certain services as long as no special fee is charged for higher-quality service.<ref name="S215">''A bill to amend the Communications Act of 1934 to ensure net neutrality'', {{USBill|110|S|215}}</ref>