SOCKET sock_udp = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
// Установка размера буфера входящих пакетов
size =  3014656;
if (setsockopt(sock_udp, SOL_SOCKET, SO_RCVBUF, (char *) &size, sizeof(size)) == -1 ) {
...
}
// Установка запрета фрагментации пакетов
int yes = IP_PMTUDISC_DO;
if(setsockopt(sock_udp, IPPROTO_IP, IP_DONTFRAGMENT, (char *) &yes, sizeof(yes)) == -1 ) {
...
}
...
sockaddr_in addr_in;
...
if(bind(sock_udp, (SOCKADDR *) &addr_in, (socklen_t) sizeof(sockaddr_in)) != 0) {
...
}
...
// Отправка
size = sendto(sock_udp, msg, size_to_send, 0, (SOCKADDR *) &addr, sizeof(sockaddr_in));
...
// Прием
socklen_t addr_size = sizeof(sockaddr_in);
int size = recvfrom(sock_udp, msg, 1472, 0, (SOCKADDR *) &addr, &addr_size);

#include <winsock2.h>
#include <Ws2tcpip.h>
#pragma comment(lib, "Ws2_32.lib")

#include <stdio.h>
#include <stdlib.h>

void send_udp(SOCKET sock, char* msg, int size, char* addr_str, int port)
{
	sockaddr_in addr;
	addr.sin_family = AF_INET;
	addr.sin_port = htons(port);
	addr.sin_addr.s_addr = inet_addr(addr_str);
	printf("send %d byte to %s:%d ", size, inet_ntoa(addr.sin_addr), ntohs(addr.sin_port));
	int start = GetTickCount();
	int send = sendto(sock, msg, size, 0, (SOCKADDR *) &addr, sizeof(sockaddr_in));
	if(send == size) {
		printf("OK pause %d msec\n", GetTickCount() - start);
	} else {
		printf("failed %d\n", send);
	}


}

void main(int argc, char* argv[])
{
	WSADATA wsaData;
	if(WSAStartup(MAKEWORD(2, 2), &wsaData) != NO_ERROR) {
		printf("WSAStartup()\n");
		return;
	}

	sockaddr_in addr_in;
	addr_in.sin_family = AF_INET;
	addr_in.sin_port = htons(0);
	addr_in.sin_addr.s_addr = htonl(INADDR_ANY);
	SOCKET sock_udp = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
	if(bind(sock_udp, (SOCKADDR *) &addr_in, (socklen_t) sizeof(sockaddr_in)) != 0) {
		printf("bind()\n");
		return;
	}

	char msg[1472];
	send_udp(sock_udp, msg, 1472, "192.168.0.1", 57691);
	send_udp(sock_udp, msg, 1472, "169.254.160.21", 57691);

	system("pause");
}

#include <winsock2.h>
#include <Ws2tcpip.h>
#pragma comment(lib, "Ws2_32.lib")

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

void send_udp_window(SOCKET sock, char* msg, int size, char* addr_str, int port, int window)
{
	sockaddr_in addr;
	addr.sin_family = AF_INET;
	addr.sin_port = htons(port);
	addr.sin_addr.s_addr = inet_addr(addr_str);
	printf("send %d packets %d byte ", window, size * window);
	clock_t start = clock();
	while(window--) {
		int send = sendto(sock, msg, size, 0, (SOCKADDR *) &addr, sizeof(sockaddr_in));
		if(send != size) {
			printf("failed %d\n", send);
		}
	}
	printf("OK time %d msec\n", clock() - start);
	Sleep(1000);
}

void main(int argc, char* argv[])
{
	WSADATA wsaData;
	if(WSAStartup(MAKEWORD(2, 2), &wsaData) != NO_ERROR) {
		printf("WSAStartup()\n");
		return;
	}

	sockaddr_in addr_in;
	addr_in.sin_family = AF_INET;
	addr_in.sin_port = htons(0);
	addr_in.sin_addr.s_addr = htonl(INADDR_ANY);
	SOCKET sock_udp = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
	DWORD size = 15000000;
	if (setsockopt(sock_udp, SOL_SOCKET, SO_SNDBUF, (char *) &size, sizeof(size)) == -1 ) {
		printf("setsockopt SO_SNDBUF failed\n");
	}

	if(bind(sock_udp, (SOCKADDR *) &addr_in, (socklen_t) sizeof(sockaddr_in)) != 0) {
		printf("bind()\n");
		return;
	}

	char msg[1472];
	char ip[] = "192.168.0.1";
	int port = 12345;
	send_udp_window(sock_udp, msg, 1472, ip, port, 10);
	send_udp_window(sock_udp, msg, 1472, ip, port, 100);
	send_udp_window(sock_udp, msg, 1472, ip, port, 1000);
	send_udp_window(sock_udp, msg, 1472, ip, port, 10000);

	system("pause");
}

C:\Download\iperf-2.0.5-3-win32>iperf -c 192.168.0.1 -u -b 500m -w 3m
------------------------------------------------------------
Client connecting to 192.168.0.1, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 3.00 MByte
------------------------------------------------------------
[  3] local 192.168.0.45 port 56435 connected with 192.168.0.1 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec   610 MBytes   511 Mbits/sec
[  3] Sent 434768 datagrams
[  3] Server Report:
[  3]  0.0-10.0 sec   610 MBytes   511 Mbits/sec   0.446 ms 61133/434767 (14%)
[  3]  0.0-10.0 sec  61134 datagrams received out-of-order


C:\Download\iperf-2.0.5-3-win32>iperf -c 192.168.0.1 -u -b 600m -w 3m
------------------------------------------------------------
Client connecting to 192.168.0.1, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 3.00 MByte
------------------------------------------------------------
[  3] local 192.168.100.45 port 58740 connected with 192.168.0.1 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec   370 MBytes   310 Mbits/sec
[  3] Sent 263880 datagrams
[  3] Server Report:
[  3]  0.0-10.0 sec   370 MBytes   310 Mbits/sec   0.105 ms 33670/263879 (13%)
[  3]  0.0-10.0 sec  33671 datagrams received out-of-order


C:\Download\iperf-2.0.5-3-win32>iperf -c 192.168.0.1 -u -b 800m -w 3m
------------------------------------------------------------
Client connecting to 192.168.0.1, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 3.00 MByte
------------------------------------------------------------
[  3] local 192.168.0.45 port 62350 connected with 192.168.0.1 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec   513 MBytes   430 Mbits/sec
[  3] Sent 365801 datagrams
[  3] Server Report:
[  3]  0.0-10.0 sec   513 MBytes   430 Mbits/sec   0.269 ms 47710/365800 (13%)
[  3]  0.0-10.0 sec  47711 datagrams received out-of-order

C:\Download\iperf-2.0.5-3-win32>iperf -c 192.168.0.1 -u -b 1000m -w 3m
------------------------------------------------------------
Client connecting to 192.168.0.1, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 3.00 MByte
------------------------------------------------------------
[  3] local 192.168.0.45 port 58409 connected with 192.168.0.1 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec   430 MBytes   360 Mbits/sec
[  3] Sent 306732 datagrams
[  3] Server Report:
[  3]  0.0-10.0 sec   430 MBytes   361 Mbits/sec   0.504 ms 39963/306731 (13%)
[  3]  0.0-10.0 sec  39964 datagrams received out-of-order

C:\Download\iperf-2.0.5-3-win32>iperf -c 192.168.0.1 -u -b -w 3m
/iperf-2.0.5-3-win32/iperf: ignoring extra argument -- 3m
WARNING: delay too large, reducing from -------------------------------------------------------------2147.
5 to 1.0 seconds.
Client connecting to 192.168.0.1, UDP port 5001
Sending 1470 byte datagrams
nanosleepUDP buffer size: 63.0 KByte (default) failed: Invalid argument

------------------------------------------------------------
nanosleep[  3] local 192.168.0.45 port 60178 connected with 192.168.0.1 port 5001 failed: Invalid argument

nanosleep failed: Invalid argument
nanosleep failed: Invalid argument
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-11.7 sec  23.0 KBytes  16.1 Kbits/sec
[  3] Sent 16 datagrams
[  3] Server Report:
[  3]  0.0-11.7 sec  23.0 KBytes  16.1 Kbits/sec   0.513 ms    0/   16 (0%)



C:\Download\iperf-2.0.5-3-win32>iperf -c 192.168.0.1 -u -w 3m
------------------------------------------------------------
Client connecting to 192.168.0.1, UDP port 5001
Sending 1470 byte datagrams
UDP buffer size: 3.00 MByte
------------------------------------------------------------
[  3] local 192.168.0.45 port 57842 connected with 192.168.0.1 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  1.25 MBytes  1.05 Mbits/sec
[  3] Sent 893 datagrams
[  3] Server Report:
[  3]  0.0-10.0 sec  1.25 MBytes  1.05 Mbits/sec   0.403 ms    0/  892 (0%)
[  3]  0.0-10.0 sec  1 datagrams received out-of-order