Re: [tcpdump-workers] single packet capture time w/pcap vs. recvfrom()

2004-05-28 Thread Darren Reed
In some email I received from Brandon Stafford, sie wrote: [ Charset windows-1252 unsupported, converting... ] > Hello, > > I'm writing a server that captures UDP packets and, after some > manipulation, sends the data out the serial port. Right now, I'm using > recvfrom(), but it takes 20 ms t

Re: [tcpdump-workers] single packet capture time w/pcap vs. recvfrom()

2004-05-26 Thread Brandon Stafford
Ryan Mooney wrote: Brandon, For curiousity sake (I have a simular app and am seriously interested in performance). - What platform (OS/processor) are you on, OpenBSD 3.4 on a HP Kayak XA, Pentium II, 233 MHz (ugh!) - How did you measure the time to call recvfrom(), or perhaps even a more relevant

Re: [tcpdump-workers] single packet capture time w/pcap vs. recvfrom()

2004-05-26 Thread Brandon Stafford
Guy Harris wrote: If a received packet has a bad IP header or UDP checksum, it should get discarded at the IP or UDP layer, so that your application would *never* see it, not just see it after 20ms. I should have been more clear-- the UDP packets have checksums of 0x00, not bad checksums. I bel

Re: [tcpdump-workers] single packet capture time w/pcap vs. recvfrom()

2004-05-26 Thread Ryan Mooney
Brandon, For curiousity sake (I have a simular app and am seriously interested in performance). - What platform (OS/processor) are you on, - How did you measure the time to call recvfrom(), or perhaps even a more relevant question is how do you use recvfrom() (whats the surrounding code lik

Re: [tcpdump-workers] single packet capture time w/pcap vs. recvfrom()

2004-05-25 Thread Guy Harris
On May 23, 2004, at 6:37 PM, Brandon Stafford wrote: I'm writing a server that captures UDP packets and, after some manipulation, sends the data out the serial port. Right now, I'm using recvfrom(), but it takes 20 ms to execute for each packet captured. I know that tcpdump can capture packe

[tcpdump-workers] single packet capture time w/pcap vs. recvfrom()

2004-05-23 Thread Brandon Stafford
Hello, I'm writing a server that captures UDP packets and, after some manipulation, sends the data out the serial port. Right now, I'm using recvfrom(), but it takes 20 ms to execute for each packet captured. I know that tcpdump can capture packets much faster than 20 ms/packet on the same