July 2015

Performance for Voip Recorder development

I'm developing our existing Voip Recording Software (Originally C++ code) with jnetpcap but I have to know if my efforts are relevant before continuing.

We currently have 300 to 400 cuncurrent calls on each server and I really need to know if the packet dumping capabilities of JNetPcap can effectivelly capture all the rtp session packets for at least 3000 concurrent calls without loss on an QuadCore high end server.

Payload of IP is not visible.

Hello, I am using JNetPcap (1.4.r1425-1f) to read PCAP-file and to analyze it. Here's the code I use:
final StringBuilder errbuf = new StringBuilder();
final Pcap pcap = Pcap.openOffline(f.getAbsolutePath(), errbuf);
if (pcap != null) {
    pcap.loop(Pcap.LOOP_INFINITE, new JPacketHandler<StringBuilder>() {
        final Tcp tcp = new Tcp();

        public void nextPacket(final JPacket packet, final StringBuilder errbuf) {
            if (packet.hasHeader(tcp))
The issue with that code is that hasHeader(tcp) returns null and my code isn't executed. If I call packet.toString(), I see only three layers (Frame, Eth, Ip), which is consistent with the result of the method hasHeader. However if I open the PCAP-file in Wireshark, I see five layers: Frame, Ethernet II, IPv4, TCP and HTTP. I attach that file so that you can check it yourself. Is it a bug?

Detecting clients if downloading

Can I use jnetpcpap for detecting clients if downloading?