Using Ethernet to communicate with equipment
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Dave / NR1DX
All
I am struggling to move to the "next level" of passing information from DXLab to various pieces of hardware via an Ethernet connection. My problem is not with DXLab per-se but rather that much of the documentation (from both DXLab and the hardware manufacturers) assumes the user knows might actually know something about Ethernet communications to begin with.... which I dont . I dont even know what half the terms mean let alone the intricacies of how to use them ....help Can someone direct me to a site that is HAMRADIO ETHERNET FOR DUMMIES. What is a UDP? what is an IP address and when and why does it need to be static and when does in need to be dynamic. What is a NET MASK and and why do I care? etc etc etc. Dave NR1DX manuals@... -- Dave Manuals@... www.ArtekManuals.com -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
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Dave AA6YQ
+ AA6YQ comments below
I am struggling to move to the "next level" of passing information from DXLab to various pieces of hardware via an Ethernet connection. "The Internet Protocol (abbreviated IP) is responsible for addressing host interfaces, encapsulating data into datagrams and routing datagrams from a source host interface to a destination host interface across one or more IP networks. For these purposes, the Internet Protocol defines the format of packets and provides an addressing system." from https://en.wikipedia.org/wiki/Internet_Protocol
"The User Datagram Protocol (UDP) is one of the core members of the Internet protocol suite. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol (IP) network. Prior communications are not required in order to set up communication channels or data paths. UDP uses a simple connectionless communication model with a minimum of protocol mechanisms. UDP provides checksums for data integrity, and port numbers for addressing different functions at the source and destination of the datagram. It has no handshaking dialogues, and thus exposes the user's program to any unreliability of the underlying network; there is no guarantee of delivery, ordering, or duplicate protection." from https://en.wikipedia.org/wiki/User_Datagram_Protocol
The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite. It originated in the initial network implementation in which it complemented the Internet Protocol (IP). Therefore, the entire suite is commonly referred to as TCP/IP. TCP provides reliable, ordered, and error-checked delivery of a stream of octets (bytes) between applications running on hosts communicating via an IP network. Major internet applications such as the World Wide Web, email, remote administration, and file transfer rely on TCP, which is part of the Transport Layer of the TCP/IP suite. SSL/TLS often runs on top of TCP.
"TCP is connection-oriented, and a connection between client and server is established before data can be sent. The server must be listening for connection requests from clients before a connection is established. Three-way handshake, retransmission, and error-detection adds to reliability but lengthens latency. Applications that do not require reliable data stream service may use the User Datagram Protocol (UDP), which provides a connectionless datagram service that prioritizes time over reliability." from https://en.wikipedia.org/wiki/Transmission_Control_Protocol
Information about IP addresses is provided here: https://computer.howstuffworks.com/internet/basics/what-is-an-ip-address.htm 73, |
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g4wjs
On 17/07/2021 13:51, Dave / NR1DX wrote:
AllHi Dave, I'll have a go with some analogies that may help. UDP is like sending a letter, fire and forget. You put a message (datagram) into an envelope (IP packet) and send it to a already known address. It may or may not arrive, but usually does. There is another protocol called TCP/IP which is more like a telephone call, a stream of information is passed back and forth between two parties as a conversation. As with UDP the data is sent in envelopes (IP packets). IP addresses are like premises addresses, you have to know them before you can send something to them. A static IP address is one way a destination gets a unique IP address and it is useful if you want others to know where to contact you (also know as well know addresses). Dynamic IP addresses are allocated by a service running on the local network from a pool, they are efficient in that they maximize the use of available addresses but are not useful as well known addresses. When data is sent from A to B with protocols like UDP and TCP/IP there is a return address passed, that allows receivers of messages to send back replies without having prior knowledge of the sender address. This is how holders of dynamic IP addresses can communicate with others. A typical exchange is a client with a dynamic IP address sends a request to a server with a well known static IP address (actually another layer called DNS is also used which allows (domain) names to be mapped to IP addresses), the server fulfills the request by replying to the client's return address. E.g. fetching a web page from a web server somewhere on the Internet. The net mask determines the scope of the local network, network local scopes can be of various sizes depending on the needs of the owner. To send data outside of the scope defined by the net mask requires a router to act as a gateway. You don't care about net masks, they are implicit to the class of network you are on. You don't ask about service port numbers, they are another fundamental part of Internet protocols. Service port numbers differentiate services offered on a particular host machine (actually on each network interface of a host machine). They are part of the addressing mechanism, e.g. port 443 is the well know port where secure webpages are served from (old insecure web servers respond on port 80). Like IP addresses there are well known port numbers and there are ephemeral ports granted to clients on a need to use basis, also like IP addresses a return port number is included with protocols like UDP and TCP/IP which complete the return address. Service port numbers allow multiple servers and clients to reside on a single host, for example you can browse the web, send and receive emails without messages from these different services getting tangled up with each other. You might think of service port numbers as different stores on a high street, although the analogy is pushing it a bit. -- 73 Bill G4WJS. |
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Jim Sanford
There's also a $5.00 book, "TCP/IP for Dummies" and an online course at udemy.com Good luck! Jim
On 7/17/2021 12:06, Dave AA6YQ wrote:
+ AA6YQ comments below |
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Norm - KC1BMD
On Sat, Jul 17, 2021 at 12:16 PM, g4wjs wrote:
A static IP address is one way a destination gets a unique IP address and it is useful if you want others to know where to contact you (also know as well know addresses).In my past work we used the term well-known with regard to "port" numbers (e.g. port numbers 0 - 1023). A static IP address is also known as a fixed or dedicated address. -- 73, Norm/KC1BMD |
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