What is the difference between “zero-copy networking” and “kernel bypass”? Are they two phrases meaning the same thing, or different? Is kernel bypass a technique used within “zero copy networking” and this is the relationship? TL;DR – They are different concepts, but it is quite likely that zero copy is supported within kernel bypass API/framework. … Read more
Pulling the network cable will not break a TCP connection(1) though it will disrupt communications. You can plug the cable back in and once IP connectivity is established, all back-data will move. This is what makes TCP reliable, even on cellular networks. When TCP sends data, it expects an ACK in reply. If none comes … Read more
The “SO_” prefix is for “socket option”, so yes, these are per-socket settings for the per-socket buffers. There are usually system-wide defaults and maximum values. SO_RCVBUF is simpler to understand: it is the size of the buffer the kernel allocates to hold the data arriving into the given socket during the time between it arrives … Read more
HTTP is an application protocol. It basically means that HTTP itself can’t be used to transport information to/from a remote end point. Instead it relies on an underlying protocol which in HTTP’s case is TCP. You can read more about OSI layers if you are interested. Sockets on the other hand are an API that … Read more
Overview What is causing the inability to send/receive data locally? Mostly buffer space. Imagine sending a constant 10MB/second while only able to consume 5MB/second. The operating system and network stack can’t keep up, so packets are dropped. (This differs from TCP, which provides flow control and re-transmission to handle such a situation.) Even when data … Read more
Use the other encode method in URLEncoder: URLEncoder.encode(String, String) The first parameter is the text to encode; the second is the name of the character encoding to use (e.g., UTF-8). For example: System.out.println( URLEncoder.encode( “urlParameterString”, java.nio.charset.StandardCharsets.UTF_8.toString() ) );
Connect to a non-routable IP address, such as 10.255.255.1.
An established connection was aborted by the software in your host machine That is a boiler-plate error message, it comes out of Windows. The underlying error code is WSAECONNABORTED. Which really doesn’t mean more than “connection was aborted”. You have to be a bit careful about the “your host machine” part of the phrase. In … Read more
The new socket is an application-level concept introduced because each established connection needs a unique file descriptor (also distinct from the listening file descriptor), which maps to, but isn’t the same as, a TCP session. The session itself is identified by the combination of source and destination address and port. The source (client) port is … Read more
This is somewhat advanced functionality which is abstracted away by both HttpWebRequest, WebRequest, WebClient and the like. You can, however, do this using TcpClient (using the constructor taking a local endpoint) or using sockets and calling Socket.Bind. Use the Bind method if you need to use a specific local endpoint. You must call Bind before … Read more