Editing Packet Switch Stream (section)

=== EPSS ===
[[Roger Scantlebury]] was seconded from the [[National Physical Laboratory (United Kingdom)|National Physical Laboratory]] to the British [[Post Office Telecommunications]] division (BPO-T) in 1969. He had worked with [[Donald Davies]] in the late 1960s pioneering the implementation of [[packet switching]] and the associated [[communication protocol]]s on the local-area [[NPL network]].<ref>{{Cite book |last=Naughton |first=John |url=https://books.google.com/books?id=bbonCgAAQBAJ&pg=PT290 |title=A Brief History of the Future |date=2015 |publisher=Orion |isbn=978-1-4746-0277-8 |language=en}}</ref><ref>{{Cite journal |last=Cambell-Kelly |first=Martin |date=1987 |title=Data Communications at the National Physical Laboratory (1965-1975) |url=https://archive.org/details/DataCommunicationsAtTheNationalPhysicalLaboratory |journal=Annals of the History of Computing |language=en |volume=9 |issue=3/4 |pages=[https://archive.org/details/DataCommunicationsAtTheNationalPhysicalLaboratory/page/n0 221]-247}}</ref><ref>{{Cite journal |last=Kirstein |first=Peter T. |date=2009 |title=The early history of packet switching in the UK |journal=IEEE Communications Magazine |volume=47 |issue=2 |pages=18–26 |doi=10.1109/MCOM.2009.4785372 |s2cid=34735326}}</ref><ref name="Early experiences with the Arpanet">{{cite journal |last1=Kirstein |first1=P.T. |date=1999 |title=Early experiences with the Arpanet and Internet in the United Kingdom |journal=IEEE Annals of the History of Computing |volume=21 |issue=1 |pages=38–44 |doi=10.1109/85.759368 |s2cid=1558618}}</ref> By 1973, BPO-T engineers had developed a packet-switching communication protocol from basic principles for an Experimental Packet Switched Service (EPSS) based on a [[virtual call capability]]. However, the protocols were complex and limited; Donald Davies described them as "esoteric".<ref name=":0">{{Cite web |last1=Smith |first1=Ed |last2=Miller |first2=Chris |last3=Norton |first3=Jim |date=2017 |title=Packet Switching: The first steps on the road to the information society |url=https://www.npl.co.uk/getattachment/about-us/History/Famous-faces/Donald-Davies/UK-role-in-Packet-Switching-(1).pdf.aspx?lang=en-GB |access-date= |website=National Physical Laboratory}}</ref><ref>{{Cite web |last=Pelkey |first=James L. |date=May 27, 1988 |title=Interview of Donald Davies |url=http://archive.computerhistory.org/resources/access/text/2017/11/102738594-05-01-acc.pdf |website=Computer History Museum}}</ref>

[[Ferranti]] supplied the hardware and software. The handling of link control messages (acknowledgements and flow control) was different from that of most other networks.<ref name=":0" /><ref>{{cite conference |last=Bright |first=Roy D. |author2=Smith, Michael A. |year=1973 |title=EXPERIMENTAL PACKET SWITCHING PROJECT OF THE UK POST OFFICE |url=http://rogerdmoore.ca/PS/EPSSB.html |conference= |location=Sussex, United Kingdom |publisher=Noordhoff International Publishing |pages=435–44 |archive-url=https://web.archive.org/web/20131020142503/http://rogerdmoore.ca/PS/EPSSB.html |archive-date=2013-10-20 |access-date=2013-08-30 |book-title=Proceedings of the NATO Advanced Study Institute on Computer Communication Networks |url-status=dead}}</ref><ref>{{cite conference |last=Pearson |first=DJ |author2=Wilkin, D |year=1974 |title=Some Design Aspects of a public packet switching network |url=http://rogerdmoore.ca/PS/EPSSFer/EF.html |conference= |pages=199–213 |archive-url=https://web.archive.org/web/20131020142152/http://rogerdmoore.ca/PS/EPSSFer/EF.html |archive-date=2013-10-20 |access-date=2013-08-30 |book-title=Proceedings of the 2nd ICCC 74 |url-status=dead}}</ref> The EPSS began operating in 1976, the first [[public data network]] in the UK.<ref>{{cite book |url=https://books.google.com/books?id=DN-t8MpZ0-wC&pg=PA2 |title=A history of international research networking: the people who made it happen |date=2010 |publisher=John Wiley & Sons |isbn=978-3527327102 |editor1-last=Davies |editor1-first=Howard |page=2 |editor2-last=Bressan |editor2-first=Beatrice}}</ref> EPSS was interconnected with [[SATNET]] and the [[NPL network]].<ref>{{Cite web |date=29 July 1977 |title=Issues in the interconnection of datagram networks |url=https://www.rfc-editor.org/ien/ien1.pdf}}</ref><ref>{{Cite web |last=Postel |first=Jon |date=August 18, 1977 |title=1.4.1 INTERNET Meeting Notes |url=https://www.rfc-editor.org/ien/ien3.txt}}</ref><ref name="Abbate00p125">{{harvnb|Abbate|2000|p=[https://books.google.com/books?id=E2BdY6WQo4AC&pg=PA125 125]}}</ref>