Ethernet transmission speed

[Altera_Forum]

My board：DE2-115 

My sopc project：webserver(RGMII)(provided by Terasic) My nios project: simple socket server   Now, I can send some words to my PC from my board by a debugging assistant software. However, the speed(working on 100Mbps) is faster than the speed working on 1000Mbps.   What I can do to raise the transfer speed? Why the 1000Mbps is slower than 100Mbps, is it because my debugging assistant software doesn't support 1000Mbps or something else??

[Altera_Forum]

What kind of socket are you using? If it is TCP then it is possible that an increase in packet loss due to the higher speed results in a slower effective speed on the socket. 

Use a sniffer software such as Wireshark to see if there is any retransmission.

[Altera_Forum]

Yeah, as you mentioned, my socket is TCP. 

Should I change it to UDP or can I do something to improve the existing situation by changing TCP Socket?   ******************my code in NIOS II******************# include <stdio.h># include <string.h># include <ctype.h># include "includes.h"# include "simple_socket_server.h"# include "alt_error_handler.h"# include "ipport.h"# include "tcpport.h"# define MAXDATASIZE 1450   void SSSSimpleSocketServerTask() {  int fd_listen;// max_socket  int fd_listen1;  int long bytes_sent;  int long bytes_recv;  int nSendBufSize=SSS_TX_BUF_SIZE;  struct sockaddr_in server_addr;  struct sockaddr_in client_addr;  fd_listen = socket(AF_INET, SOCK_STREAM, 0);  setsockopt(fd_listen,SOL_SOCKET,SO_SNDBUF,(char * )&nSendBufSize,sizeof(int));  if (fd_listen< 0)   {  alt_NetworkErrorHandler(EXPANDED_DIAGNOSIS_CODE,"[sss_task] Socket creation failed");  }  else  {  printf("Socket created");  }  server_addr.sin_family = AF_INET;  server_addr.sin_port = htons(SSS_PORT);  server_addr.sin_addr.s_addr = INADDR_ANY;  memset(&(server_addr.sin_zero), '\0', 8);  if ((bind(fd_listen,(struct sockaddr *)&server_addr,sizeof(server_addr))) < 0)  {  alt_NetworkErrorHandler(EXPANDED_DIAGNOSIS_CODE,"[sss_task] Bind failed");  }  else  {  printf("Bind is OK\n");  }  if ((listen(fd_listen,5)) < 0)  {  alt_NetworkErrorHandler(EXPANDED_DIAGNOSIS_CODE,"[sss_task] Listen failed");  }  else  {  printf("Listen is OK\n");  }  int client_addrlen;  client_addrlen=sizeof(client_addr);  fd_listen1 = accept(fd_listen,(struct sockaddr *)&client_addr,&client_addrlen);  while(1)  {  if(fd_listen1<0)  {  alt_NetworkErrorHandler(EXPANDED_DIAGNOSIS_CODE,"[sss_task] Accept creation failed");  }  else  {  printf("accepted connection request\n");  }  fd_listen = fd_listen1;  break;  }  printf("Server: Sending some test data to client...\n");  char sendbuf[MAXDATASIZE] = "Bjtuxuxu Love FPGA!";  char recvbuf[200] = "Bjtu"; while(1) {  bytes_sent = send(fd_listen,sendbuf,SSS_BUF_LEN,0); }  if(bytes_sent<0)  {  alt_NetworkErrorHandler(EXPANDED_DIAGNOSIS_CODE,"[sss_task] Send failed");  }  else  {  printf("SERVER : Send is OK \n");  printf("SERVER : Bytes sent:%ld.\n",bytes_sent);  }  bytes_recv = recv(fd_listen,recvbuf,200,0);  if(bytes_recv<0)  {  alt_NetworkErrorHandler(EXPANDED_DIAGNOSIS_CODE,"[sss_task] Recv failed");  }  else  {  printf("SERVER: recv() is OK.\n");  printf("SERVER: Received data is: \"%s\"\n", recvbuf);  printf("SERVER: Bytes received: %ld.\n", bytes_recv);  }  return ; }  ******************my code in NIOS II****************** Thanks for your reply.

[Altera_Forum]

It depends on your needs. UDP is usually faster and has a lower latency, but you have no guarantee a packet you send will even be received. If you need something safer and need all your data to be transmitted, and retransmitted if necessary, then you should use TCP. 

To know what the problem is, you need to analyse the traffic with a sniffer such as Wireshark and see what's wrong.