UDP thoroughput

Hello!

Sorry if it's a FAQ, but nevertheless:

Let's say I have a server that waits for UDP datagrams, and client that
sends 700 1000-byte datagrams as fast as it can over loop-back
interface. Upon receiving a datagram, server increments and prints a
counter. On average, only 75 datagrams arrive. If I add a timeout to
client, all 700 arrive. net.core.rmem_max = 8388608
Linux 2.6.13 i686
Is it expected behaviour? Is there anything to do about it?
My test code is below.

Thank you for any opinion,
Dmitri
(gone to read Stevens)

server:

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
int sock, length, fromlen, n=0;
struct sockaddr_in server;
struct sockaddr_in from;
char buf[2048];

sock=socket(AF_INET, SOCK_DGRAM, 0);
length = sizeof(server);
bzero(&server,length);
server.sin_family=AF_INET;
server.sin_addr.s_addr=INADDR_ANY;
server.sin_port=htons(1234);
bind(sock,(struct sockaddr *)&server,length);
fromlen = sizeof(struct sockaddr_in);
while (1) {
recvfrom(sock,buf,2048,0,(struct sockaddr *)&from,&fromlen);
printf("%d\n", n++);
}
}

client:

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <unistd.h>

int main(int argc, char *argv[])
{
int i, sock, length, n;
struct sockaddr_in server, from;
struct hostent *hp;
unsigned char buffer[1095];

sock= socket(AF_INET, SOCK_DGRAM, 0);

server.sin_family = AF_INET;
hp = gethostbyname("localhost");

bcopy((char *)hp->h_addr, (char *)&server.sin_addr, hp->h_length);
server.sin_port = htons(1234);
length=sizeof(struct sockaddr_in);
for (i=0; i<1095; i++) buffer[i]=255;
buffer[0]=17; buffer[1]=0;
for (i=0; i<700; i++) {
sendto(sock,buffer,1095,0,&server,length);
/*usleep(1);*/
}
}

.

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