Definition of the Internet

1. Definition of the Internet • Network of networks • millions of smaller domestic, academic, business, and government networks • Uses TCP/IP protocol suite • Carries various information and services, such as electronic mail, online chat, file transfer, documents of the World Wide Web. • Internet and the World Wide Web are not synonymous: • the Internet is a collection of interconnected computer networks, linked by telecommunication media • the Web is a collection of interconnected documents, linked by hyperlinks and URLs. TECO-WIS, Seoul

2. Common Protocols allow Coexistence • Internet can be used as: • an underlying technology for some components of the GTS in special conditions • as a backup to the GTS • as a complement to the GTS TECO-WIS, Seoul

3. Telecommunication Options TECO-WIS, Seoul

4. VPN Concept TECO-WIS, Seoul

5. Virtual Private Networks (VPN) Create the equivalent of a dedicated private link using the Internet as a connection media TECO-WIS, Seoul

6. 100Mbps (max) China 100Mbps (max) Japan 10Mbps (max) Hong Kong 2Mbps India 100Mbps (max) Australia 4Mbps Iran Internet 256Mbps (min)-440Mbps (max) 1Mbps Brunei Korea 3Mbps Malaysia 512Kbps Oman 2Mbps 2Mbps New Zealand Saudi Arabia 1Mbps 2Mbps Vietnam Singapore Established VPN-link with Japan Soon established VPN-link with Japan WIS VPN Pilot Project in Regions II and V (as of Sept 2006) TECO-WIS, Seoul

7. File Transfers and FTP servers • Uses File Transfer Protocol • Can be used for dissemination or exchange of bulk meteorological data through Internet, GTS or other local/wide area networks • Recommended for predefined users • Efficient data exchange protocol • Good for both push and pull configurations • File Naming is important – see Man 386 Att II.15 TECO-WIS, Seoul

8. FTP Server Implementation TECO-WIS, Seoul

9. Electronic Mail • Uses the Simple Mail Transfer Protocol (SMTP) • Complementary method of data input into the GTS • Should not be used to replace GTS data exchanges for mission critical components • Usually can not guarantee real time data delivery • Requires sites to collect messages (some examples: Washington, New Zealand, Tokyo, Beijing) • Requires a strong quality control at the collecting center as the collected messages often contain several typing or format mistakes • Mostly a push mechanism • May be used for notification (for example that a file is available for delivery while the file itself is placed on an FTP server) • Excellent general communication tool • Important entry point for virusses, worms and Trojan Horses • Must deal with SPAM problem • Spamming is the abuse of electronic messaging systems to send unsolicited, undesired bulk messages TECO-WIS, Seoul

10. Email Implementation TECO-WIS, Seoul

11. Web Servers • Based primarily on Hyper Text Transfer Protocol (HTTP) • Used to make available various data and reports, available to users who request the information by downloading the various « web pages » (pull mechanism) • Offers an intuitive approach to presentation of data and links between data elements • Allows complex scripts and data management tools to be added • Requires permanent connection to the Internet • Requires careful and significant planning and maintenance • Weather data is updated very often • Demand for weather data can be very high • In large sites can become very complex TECO-WIS, Seoul

12. Web Server Implementation TECO-WIS, Seoul

13. Important Documents http://www.wmo.int/web/www/documents.html • Manual 386, Attachment II.15 – Use of TCP/IP on the GTS (Revision 3, Sept 2006) • Guide on Information Technology Security (Sept 2006) • Guide on Internet Practices (Sept 2006) • Guide on use of FTP and FTP servers at WWW centres (Sept 2006) • Guidance on IPSec-based VPNs over the Internet (April 2004) TECO-WIS, Seoul