Four big telecommunication companies offer telegraph, telex and telephone services. Telegraph, facsimile, and telex were all in use. Telex (TELegraph EXchange) was a public switched network of teleprinters. Deals were made bilaterally between two parties by telephone and confirmed by telex. AT&T bought Western Union's electronic mail and Telex businesses in 1990. The company merged with Telex Communications in 1998. By 1954, the public inland telex service opened via manually switched exchanges. The Dutch company sent an acceptance by telex. There was no charge to Prestel users for receiving Telex messages. Brinkibon sent their acceptance to a Stahag offer by Telex to Vienna. Customers on any telex exchange could deliver messages to any other, around the world. The Western Union Telex network was built on three levels of exchanges. The dominant supplier of the telex machines was Creed, a division of ITT. The protocol was designed by ARINC and deployed in 1978, using the Telex format. Mnemonics like Telex and Vietnamese Quoted-Readable (VIQR) were adapted for these systems.