dfk@unido.UUCP (06/07/85)
>Supposedly you can >call in to your local access point in, say, Australia just as you would >with Telenet or Tymnet, then ask for any other PSN . You get connected >to, say, France and log on again with them (I am assuming you have >established accounts with these organizations). Then you ask for your >end point address and - bingo! half way around the world. Actually it's much simpler than that. There is a worldwide numbering plan for data networks called CCITT X.121. Each net has it's four digit Identification Code called DNIC. The first three digits specify the country (a country may have more than one 3-digit prefix). The networks may use ten further digits to address their customers. If you want to get to unido's X.25 login ports from anywhere in the world you can just connect to 2624 5 2310 421 40. I did group the digits for readability. The Germany X.25 net "Datex-P" uses a hierarchical structure inside. The 5 means a certain class of subscribers I think. The 2310 is Dortmund's are code (same digits as in the phone network but padded differently). 421 denotes our subscriber line and finally we have 100 subaddresses that we use to select hosts and services via an inhouse X.25 switch. In Germany (and Europe in general) we are charged for all connections by our PTTs who run the networks. They are supposed to take care of the cashflow between them. So it's very convenient. Here is a top level directory: Data Network Identification Codes 204 NL Netherlands 206 B Belgium 2080 TRANSPAC French Transpac 208 F France 2141 SPAIN Spanish data network 214 E Spain 222 I Italy 228 CH Switzerland 232 A Austria 2341 IPSS IPSS UK network 2348 TELEX UK Telex network 234 GB United Kingdom 238 DK Denmark 2405 SWEDEN Swedish data network 240 S Sweden 2422 NORWAY Norwegian data network 242 N Norway 244 SF Finland 2624 GERMANY German data network 262 D Germany 268 P Portugal 270 L Luxembourg 272 IRL Ireland 3020 DATAPAC Canadian Datapac 3025 GLOBEDAT Canadian Globedat 3029 INFOSWITCH Canadian Infoswitch 302 CDN Canada 3103 ITT USA - ITT 3104 WUI USA - WUI 3106 TYMNET USA - Tymnet 3110 TELENET USA - Telenet 3113 RCA USA - RCA 3126 AUTONET USA - Autonet 340 FA French Antilles 342 BDS Barbados 425 IL Israel 4408 VENUSP Japanese data network 440 J Japan 454 HK Hong Kong 505 AUS Australia 525 SGP Singapore 530 NZ New Zealand 431 DXB United Arab Emirates - Dubai 426 BRN Bahrain 655 ZA South Africa -Daniel Karrenberg <dfk@unido.uucp>