Archive Builders: (310) 937-7000
SteveGilheany@ArchiveBuilders.com
Archive Builders: (310) 937-7000
SteveGilheany@ArchiveBuilders.com
Please see the diagram below: A map of the United States with two Internet Backbones: M, (circles) and U (squares) overlaying the map.
User A in Los Angeles is connected to their ISP (Internet Service Provider).
User A starts their Internet Browser, at level 7 of the Internet Protocol Stack (diagramed on the page after the map of the United State).
User A at level 7 interacts logically with level 7 at User B (the Internet based bookstore) via the dashed arrow M.
User A at level 7 uses level 6 of User A’s protocol stack to send information to level 7 of User B. User A uses arrow A to communicate between level 7 and level 6 of User A’s protocol stack.
(User B uses arrow L to communicate between level 7 and level 6 of User B’s protocol stack.)
User A interacts with the Browser using the Browser GUI (Graphical User Interface) at level 6.
User A initiates a session with an Internet based bookstore at the Session level, level 5.
User A’s browser formats the logon message and puts the user’s name and password in the logon message. This occurs at level 4.
The logon message is broken into uniformly sized packets for transmission over the Internet (level 3)
User A’s ISP sends the packet into the Internet at a Backbone U node (square).
The packets are placed in blocks of bits that are sent over a point- to-point communications link (level 2) with a CRC (Cyclical Redundancy Check) that detects bits that are lost on the communications link and that cause the level 2 protocol to request the retransmission of bit blocks that have errors.
The bit blocks area sent over physical wires or radio waves. (the physical layer, layer 1). The physical layer merely moves one bit at a time from one physical location to another.
Packets move from node to node over the Internet using protocol levels 1 and 2.
The packets eventually move to one of several links between Backbone M (circle) and Backbone U (square). One of the links between the two backbones is in Chicago.
Each of the packets moves across the internetworking link (inter- backbone). This is the action that gives the Internet its name. The packets then move through Backbone M (circles).
The packets eventually get to the Raleigh node of Backbone M (circles) and are delivered to the ISP of B (the online book store).
The packets are put back in order and assembled into a log on message. (level 4)
The log on message is used to start a session during which user A can select and buy books. (level 5, the session level).
The user book requests are formatted for the book purchase application (at level 6, the presentation level).
The user book requests are entered into the bookstore database by the book buying application at level 7, the application level.
At any time, all of the communications at a given level can be gathered up and placed in a level 7 message.
If the communication is gathered up at level 3 or lower, then the communication can be placed in level 3 packets for transmission.
This interception and gathering up is called tunneling. The level at which the communications is gathered up is simulated by the higher level.
Tunneling makes it possible to simulate a physical wire that goes from any one point on the Internet to any other point on the Internet. Any level of the Internet protocol can be simulated by tunneling.
Because any one of a number of protocols (transmission agreements) can be used at any level), the Internet makes use of a wide variety of protocols. For any one message, one protocol is used at each level of the Internet protocol stack, for a total of 7 protocols for each communication.
This is why establishing one protocol, such as TCP (Transmission Control Protocol) or the IP (Internet Protocol) or the use of both together as in TCP/IP does not fully define a communication link. The physical link, such as 100 BaseT for twisted pair wires is also needed, among others.
When using the information in this article, please check the website http://www.ArchiveBuilders.com for updates. The version number of this article is just before the page number below. The website also has articles that provide more details on some of the terms and concepts in this article.
Please let us know how you like this paper, or if you had any questions. What would you like to see in the future? Also, please let us know where you saw this paper. For more, and the most recent version of this article, please visit our web site at http://www.ArchiveBuilders.com Please send your comments via email to SteveGilheany@ArchiveBuilders.com. Tel: +1 310-937-7000. Fax: +1 310- 937-7001. Also, please let us know where you saw this article.
Reprinted from Archive Planning, Volume 4, number 3, 2000, Archive Builders' analysis newsletter for document management. See http://www.ArchiveBuilders.com. All trademarks are the property of their respective holders.
We will continue to update these articles as we get comments. Please contact us for the most current version before you publish. Also, please request permission to publish the article. Permission will be given freely for most purposes.
Steve Gilheany
Archive Builders
1209 Manhattan Ave., PMB C-14
Manhattan Beach, CA 90266
Tel: +1 310-937-7000 Fax: +1 310-937-7001
SteveGilheany@ArchiveBuilders.com
If you decide to divide this article into parts please print at least the updates, comments, and acknowledgements sections in each of the parts along with: ‘by SteveGilheany@ArchiveBuilders.com’.
Steve Gilheany, BA in Computer Science, MBA, MLS Specialization in Information Science, CDIA (Certified Document Imaging System Architect), AIIM Master (MIT), and AIIM Laureate (LIT), of Information Technologies, CRM (Certified Records Manager, ARMA) has nineteen years experience in document imaging and is a Sr. Systems Engineer at Archive Builders.
Steve Gilheany is a Sr. Systems Engineer at Archive Builders. He has worked in digital document management and document imaging for nineteen years.
His experience in the application of document management and document imaging in industry includes: aerospace, banking, manufacturing, natural resources, petroleum refining, transportation, energy, federal, state, and local government, civil engineering, utilities, entertainment, commercial records centers, archives, non-profit development, education, and administrative, engineering, production, legal, and medical records management. At the same time, he has worked in product management for hypertext, for windows based user interface systems, for computer displays, for engineering drawing, letter size, microform, and color scanning, and for xerographic, photographic, newspaper, engineering drawing, and color printing.
In addition, he has nine years of experience in data center operations and database and computer communications systems design, programming, testing, and software configuration management. He has an MLS Specialization in Information Science and an MBA with a concentration in Computer and Information Systems from UCLA, a California Adult Education teaching credential, and a BA in Computer Science from the University of Wisconsin at Madison. His industry certifications include: the CDIA (Certified Document Imaging System Architect) and the AIIM Master (MIT), and AIIM Laureate (LIT), of Information Technologies (from AIIM International, the Association of Information and Image Management, http://www.AIIM.org, and the CRM (Certified Records Manager) (from the ICRM, the Institute of Certified Records Managers, an affiliate of ARMA International, the Association of Records Managers and Administrators, http://www.ARMA.org.
SteveGilheany@ArchiveBuilders.com Tel: +1 310-937-7000 Fax: +1 310-937-7001
