paycheck earner feels ashamed to have to ask for professional help. We all know how hard it is to make a $100k let alone
and Pride and Prejudice as Revisions. Claire Tomalin briskly describes my task: “
talking about [Austen's] revisions” of the first versions of Sense and Sensibility ...
and Communication Technologies in Modern ... technical, and business activities. Photonics and ... ment of modern food packaging technologies are related to.
(Key Words: Beef Cattle, Maternal Effects, Growth, Preweaning Period, ... There were three different phases of ... Henderson's method III was used, as out-.
infantis, the nonabsorbable antibiotic rifaximin, and alos- etron. Additionally, there is persuasive evidence to suggest that selected antispasmodics and ...
Sep 10, 2010 - Early in their marriage, John quit his job as a machinist and ... school in 1979, John allegedly told Mit
Sep 10, 2010 - would make Mitchell a 50/50 partner in John's Used Cars. ... responsible for the operation of Sigg's Auto
Dr. Fonn enters into this Consent Agreement being fully informed of his rights ... 3
. Within thirty days of the effective date of this Consent Agreement, Dr. Fonn ...
The fate of previously focused working memory content: Decay or/and inhibition? Johannes GroÃer & Markus Janczyk. Department of Psychology III. University ...
structure, it is important to describe the family's concept/definition I am going to use in this context. ... In sociology a social institution is assimilated to a living organism, composed by ... This structural-functional approach is not free from
[email protected]. Roderick Murray-Smith ... [email protected] ... alternative is Apple's iPod click wheel [5] which enables users to ...
Sep 29, 2005 ... Electroencephalography and Evoked Potentials. Reza Gorji ...
Electroencephalography or EEG is the summation and recording of postsynaptic.
MYCETOPHILIDAE, CULICIDAE, AND CHIRONOMIDAE AND. ADDITIONAL
RECORDS OF SIMULIIDAE, FROM. THE MARQUESAS ISLANDS*. By.
Aug 16, 2007 - Stara Reka I, between Kotel and Stara Reka village (N42"55'1gn, ... Malkata Reka I, near Malko Popovo village (N4lo35'02", E25"55'06"), coll.
The Stokes radius of the pro- teins in the fractions that had the ..... al., 1993) and 42 and 100 kDa (Henley et al., 1992; Kerry et al.,. 1993) add credence to the ...
Feb 8, 2016 - Vectren's energy efficiency programs achieve record energy ... Gas and electric residential and business r
Jan 7, 2011 - carried out in which a female student-confederate mimicked or not mimicked a partic- ipant during a discussion about paintings and, after that, ...
acid, and lactic acid; inorganic acids such as hydrochloric acid [4â6]; and ...... [57] D. Garlotta, A literature review of poly (lactic acid), Journal of Polymers and the.
shatavarin IV alkaloids, proteins, starch and tanni ... following prescribed methods [9, 10]. ..... antioxidant activity of plant extract is influenced by many factors,.
then their tendering decisions will be nonstrategic -- being based on a simple comparison of gains ... bargaining, the effect on competition of bidding by well-informed target managers .... This model allows for possible informational .... it is a do
... and Development Centre,. Turku School of Economics and Business Administration ..... Figure 5 Quantitative and qualitative methods applied. .... no body of methods, no comprehensive methodology, for the study of the impact of the policy'.
components with the grain size optimised at different locations, based upon the likely .... called ImageJ was used to determine primary γⲠvolume fraction.
lung cancer in smokers, and the study had to be stopped prematurely. Today experts in nutrition .... mentioned numerous times in the bible. Mount Tabor was a ..... Quantitative risk assessment requires answers to the following questions: 1. What were
Net-overlapping TCP/IP connection ..................................... 31 ..... A simple UDP
peer in VB .................................................... 107. Socket programming in Delphi .
W&T
TCP/IP-Ethernet and Web-IO
This booklet has been produced for all those without special knowledge of computer networks who want to put Ethernet terminal units under TCP/IP into operation. It is divided into four parts: •
Understanding TCP/IP-Ethernet Here you will find the most important basic information about TCP/IP.
•
Further protocols and services In this section you will find out how E-Mail works, what happens when a web page is called up and which important protocols and services you can come across in connection with TCP/IP-Ethernet.
•
Installing TCP/IP -Ethernet Here the installing of TCP/IP-Ethernet on PCs with the common operating systems is described.
•
The small ABC of networks Here we explain the most important terms and abbreviations that you can come across in dealing with networks.
All important sequences and interrelationships will be explained clearly. Do not worry: We will not get lost in details. We have deliberately restricted ourselves to things which are really important for an understanding of the technologies described. In the end it is not necessary to know every detail of every protocol to be able to put TCP/IP network components into operation.
1
W&T
Table of Contents
Foreword .................................................................................................. 1 Understanding TCP/IP-Ethernet ....................................................... 7 Computer network requirements ............................................ 8 Basic functions of networks ................................................. 10 Ethernet and FastEthernet ................................................................ 11 10Base2 ......................................................................... 11 10BaseT ......................................................................... 11 10Base 5 ......................................................................... 12 100Base T4 ..................................................................... 12 100BaseTX ...................................................................... 12 TCP/IP – the most important protocols ..................................... 15 IP – Internet protocol ........................................................... 15 IP addresses ....................................................................... 16 Class A: .......................................................................... 16 Class B: ........................................................................... 16 Class C: .......................................................................... 17 IP data packets ................................................................... 18 TCP – Transport Control Protocol ......................................... 19 UDP – User Datagramm Protocol .......................................... 22 TCP/IP-Ethernet .................................................................. 23 ARP – Address Resolution Protocol ...................................... 26 Gateway and Subnet-Mask ................................................... 28 Net-overlapping TCP/IP connection ..................................... 31 DHCP – Dynamic Host Configuration Protocol ...................... 36 Allocation of the IP address from an address pool ............. 37 Allocation of a reserved address ....................................... 38 Exclusion of certain IP addresses ...................................... 40 from the DHCP configuration ........................................... 40 DHCP and routers ............................................................ 40 DNS – the Domain Name System .......................................... 41 Domain names ................................................................ 41 Resolving of names in DNS ............................................... 43 DNS in Embedded Systems ............................................... 44 DHCP and DNS ................................................................ 45
2
W&T
Further protocols and services ...................................................... 47 WWW – World Wide Web ....................................................... 48 URL - Uniform Resource Locator .......................................... 49 HTML – Hypertext Markup Language .................................... 52 Basic construction of an HTML file .................................... 53 Hyperlinks ...................................................................... 54 Depiction of multimedia contents ..................................... 55 HTTP – Hypertext Transfer Protocol ..................................... 59 The most important HTTP commands and parameters ....... 60 The GET command .......................................................... 60 The POST command ........................................................ 62 The HEAD command ........................................................ 63 HTTP versions ................................................................. 63 Interactivity in the WWW .................................................................. 65 Interactivity through programmes that run on the server ....... 65 CGI - Common Gateway Interface ...................................... 65 PHP ................................................................................ 66 Programmes that are run in the browser. ............................... 67 JavaScript ........................................................................ 67 Java Applets .................................................................... 69 E-Mail ....................................................................................................... 71 Construction of an E-Mail .................................................... 72 MIME – Multipurpose Internet Mail Extensions ....................... 74 SMTP – Simple Mail Transfer Protocol .................................... 74 POP3 – Post Office Protocol version 3 .................................. 75 Sending and receiving E-Mail via HTTP .................................. 76 E-Mail and DNS ................................................................... 78 Telnet - Terminal over Network .................................................... 80 The Telnet client ................................................................. 80 The Telnet server ................................................................ 81 The Telnet protocol ............................................................ 81 FTP - File Transfer Protocol ............................................................ 84 Der FTP client ..................................................................... 84 The FTP protocol ................................................................ 85 The FTP server .................................................................... 87 TFTP - Trivial File Transfer Protocol .......................................... 88
3
W&T
SNMP - Simple Network Management Protocol ........................ 92 Modbus-TCP .......................................................................................... 93 Socket programming ......................................................................... 94 TCP client, TCP server or UDP peer? ...................................... 95 TCP ................................................................................ 95 TCP client ....................................................................... 96 TCP server ...................................................................... 96 UDP ................................................................................ 97 Socket programming in Visual Basic .......................................... 98 A TCP client in VB ............................................................... 98 A TCP server in VB ............................................................ 103 A simple UDP peer in VB .................................................... 107 Socket programming in Delphi .................................................. 109 A TCP client in Delphi ....................................................... 109 A TCP server in Delphi ....................................................... 114 INSTALLING TCP/IP -Ethernet ...................................................... 121 Installing and configuring TCP/IP under Windows 9x .......... 122 Installing and configuring TCP/IP under Windows NT .......... 126 Installing and configuring TCP/IP under Win 2000 .............. 129 TCP/IP-Ethernet with simultaneous data-comms Internet access .......................................................................... 131
A Small ABC of Networks ............................................. 134 Numbering systems ........................................................................ 149 Serial equipment right on the network .................................... 150 Com-server mini and industry ............................................ 150 Com-server display ........................................................... 151 OEM boards ..................................................................... 151 Web-IO - The Terminal right at the Network ..................... 152 IO-Mailer .......................................................................... 152 Web-Thermometer ............................................................ 153 Universal digital Web-IO .................................................... 153 Fieldbus gateways ............................................................ 153
4
W&T
TCP/IP-Ethernet
TCP/IP is a purely logical protocol and always requires a physical base. As already mentioned at the beginning, Ethernet today enjoys the widest use of the physical network topologies. Ethernet is also found as the physical base in most TCP/IP networks. TCP/IP and Ethernet are brought together by embedding every TCP/IP packet in the user data area of an Ethernet packet.
Setup of a TCP/IP Ethernet data packet TCP HEADER (Port)
IP HEADER (IP address)
ETHERNET HEADER (Ethernet addressen)
TCP user data area
IP user data area
Ethernet user data area
FCS
On the way from the application on the PC to the network the user data passes by several driver layers: •
• •
•
The application programme decides to which other network users the data should be sent and passes on the IP address and TCP port to the TCP/IP driver (also often called TCP/IP stack). The TCP/IP driver coordinates the setup of the TCP connection. The user data passed over from the application programme are divided by the TCP driver, according to size, into smaller transmittable blocks. Every data block is first of all packed by the TCP driver in a TCP packet.
23
W&T
from Port 1025
TCP to Port 8000
• •
The TCP driver passes on the TCP packet and the IP address of the receiver to the IP driver. The IP driver puts the TCP packet in an IP packet. TCP fromt 1025 Por
an t 8000 Por
from 172.16.232.49
IP
to 172.16.232.23
•
The IP driver searches in the so-called ARP table (Address Resolution Protocol) for the Ethernet address of the receiver indicated by the IP address (more about this later) and passes on the IP packet together with the Ethernet address identified to the Ethernet card driver.
•
The Ethernet card driver puts the IP packet in an Ethernet packet and passes on this packet via the network card to the network. IP 2.49 from .16.23 172 2.23 an .16.23 172 from Ethernet 00-34-17-B8-71-55
to 00-C0-3D-00-23-A4
The procedure is carried in the reverse order at the receiver:
24
W&T
•
The Ethernet card recognises from the Destination-Ethernet Address that the packet is meant for the network user and passes it on to the Ethernet driver.
•
The Ethernet driver isolates the IP packet and passes it on to the IP driver.
•
The IP driver isolates the TCP packet and passes it on to the TCP driver.
•
The TCP driver checks the contents of the TCP packet for correctness and passes on the data, with the aid of the port number, to the correct application.
At first glance this multilayered transmission process seems enormously complicated. But only the strict separation of logical protocol (TCP/IP) and physical protocol (Ethernet) makes it possible to exchange net-overlapping and hardware-independent data.
