Editing Xfinity (section)

==Cable telephony==
'''Xfinity Voice''' (formerly '''Comcast Digital Voice''') is a Voice Over IP [[cable telephony]] service that was launched in 2005 in some markets,<ref name="Ben Charny">{{cite web|url=http://news.cnet.com/Comcast-pushes-VoIP-to-prime-time/2100-7352_3-5519446.html|title=Comcast pushes VoIP to prime time|publisher=Cnet|author=Ben Charny |date=January 10, 2005|access-date=February 17, 2014}}</ref> and to all of Comcast's markets in 2006. Comcast's older service, Comcast Digital Phone, continued to offer service for a brief period, until Comcast shut it down around in late 2007.<ref>{{cite web|url=https://www.courant.com/2007/10/17/comcast-ends-older-phone-service/|title=Comcast Ends Older Phone Service|publisher=Hartford Courant|author=MARK PETERS|date=October 17, 2007|access-date=March 8, 2014}}</ref> In 2009, after completing transition from their old service, Comcast had 7.6 million voice customers.<ref>{{cite web|url=http://www.cmcsk.com/releasedetail.cfm?ReleaseID=442388|title=Comcast Reports Fourth Quarter and Year End 2009 Results|date=February 3, 2010|access-date=March 8, 2014}}</ref> As of the end of 2013, Comcast Digital Voice had reached 10.7 million subscribers.<ref>{{cite web|url=http://www.cmcsa.com/releasedetail.cfm?ReleaseID=821438|title=Comcast Reports 4th Quarter and Year End 2013 Results|publisher=Comcast|date=January 28, 2014|access-date=March 8, 2014}}</ref>

At the start of 2012, Comcast stood as the United States' third-largest residential line provider,<ref name=LRG>Leichtman Research Group, [http://www.leichtmanresearch.com/research/notes04_2012.pdf "Research Notes,"] First Quarter 2012, pg. 5. The company first gained status as the USA's third largest phone company in 2009. See: [http://www.dslreports.com/shownews/Comcast-Now-Third-Largest-Phone-Company-101317 Comcast Now Third Largest Phone Company], ''DSLreports.com'', March 11, 2009.</ref> supplying 9.34 million residential lines.<ref name=LRG />

Xfinity Voice allows communication over the internet using [[VoIP]], but uses a [[private network]] instead of a [[PSTN|public IP address]], which allows Comcast to prioritize voice data during heavy traffic. In technical terms, on Comcast's [[Hybrid Fiber Coaxial]] network, calls are placed into individual Unsolicited Grant Service flows, based on [[DOCSIS]] 1.1 [[Quality of service]] standards. For the customer, this has the benefit of preventing network congestion from interfering with call quality. Other, non-Comcast VoIP services on Comcast's network must use the lower priority public IP addresses. This separation of traffic into separate flows, or [[Smart pipe]], has been criticised as a violation of [[net neutrality]], whereby all data traffic should be treated equally—[[dumb pipe]].<ref>{{cite web|url=http://www.multichannel.com/internet-video/smart-pipes-dumb-pipes-and-qos/129650|title=Smart Pipes, Dumb Pipes and QoS|publisher=MultiChannel|author= Leslie Ellis|date=February 17, 2006|access-date=March 8, 2014}}</ref> The practice was questioned by the FCC in 2009.<ref>{{cite web|url=http://gigaom.com/2009/01/19/fcc-asks-if-comcast-slows-rivals-voip-traffic/|title=FCC Asks if Comcast Slows Rivals' VoIP Traffic|publisher=Gigaom|author=Stacey Higginbotham|date=January 19, 2009|access-date=March 7, 2014}}</ref> In their response, Comcast stated that services that use [[telecommunication]]s are not necessarily [[telecommunications service]]s, and said that the FCC's designation of Comcast Digital Voice as an [[information service (US law)|information service]] exempted it from telecommunications service regulations on traditional landline. Comcast also said that because Comcast Voice was a separate service, it was unfair to directly compare the data for Comcast Voice with the data for other VoIP services.<ref>{{cite web|url=http://downloads.comcast.net/docs/january-30-2009-comcast-fcc-response.pdf |title=In the Matter of Formal Complaint of Free Press and Public Knowledge Against Comcast Corporation for Secretly Degrading Peer-to-Peer Applications, File No. EB-08-IH-1518|publisher=Comcast|author=Kathryn A. Zachem|date=January 30, 2009|access-date=March 8, 2014}}</ref><ref>{{cite web|url=https://arstechnica.com/tech-policy/2009/02/comcast-strikes-back-on-fcc-voip-probe/|title=Comcast defends itself against FCC's VoIP probe|publisher=ArsTechnica|author=Matthew Lasar|date=February 3, 2009|access-date=March 8, 2014}}</ref>

Because telephone services over VoIP are not automatically tied to a physical address, Xfinity Voice utilizes [[E911]] to help [[9-1-1|911]] emergency service operators to automatically locate the source of the 911 call.<ref>{{cite web|url=http://www.prnewswire.com/news-releases/comcast-launches-comcast-digital-voicer-phone-service-in-santa-barbara-county-61850297.html|title=Comcast Launches Comcast Digital Voice(R) Phone Service in Santa Barbara County|publisher=PR Newswire|author=Comcast Corp.|access-date=March 11, 2014}}</ref> Voice calls are delivered as a digital stream over the Comcast network, signal is converted to analog [[plain old telephone service]] lines at the cable modem, which outputs on standard physical analog style [[RJ-11]] ports.

This is separate from their former offering of "Comcast Digital Phone" which is not VoIP. The Digital Phone terms of service is still up which clearly defined this service as Circuit Switched.