Prestel
In 1983, the Prestel messaging service known as “Prestel Mailbox” was launched, initially hosted on the computer known as "Enterprise", and later available from all IRC computers by means of a centralised messaging computer known as "Pandora". This facility extended the original day one concept of “Response Frames” whereby an end user could send a message back to the IP who owned the page via special pages, for example to order goods or services. The user’s name, address, telephone number, and date could be added automatically to the message when the IP set up the response frame by means of codes which triggered extraction of key data from the users account held on the IRC computer. Initially response frames were ingathered by an IP from each IRC individually, but later the facility to collect messages from all IRCs at the UDC from where they could be ingathered centrally was implemented, and with the introduction of Mailbox, they could be retrieved from any IRC.
Recursive Internetwork Architecture
1983. First opportunity to fix addressing missed. The need for application names and distributed directories that mapped application names to internetwork addresses was well understood since mid-1970s. They were not there at the beginning since it was a major effort and there were very few applications, but they were expected to be introduced once the “host file” was automated (the host file was centrally maintained and mapped human-readable synonyms of addresses to its numeric value). However, application names were not introduced and DNS, the Domain Name System, was designed and deployed, continuing to use well-known ports to identify applications. The advent of the web and HTTP caused the need for application names, introducing URLs. However the URL format ties each application instance to a physical interface of a computer and a specific transport connection (since the URL contains the DNS name of an IP interface and TCP port number), making multi-homing and mobility very hard to achieve.