Wireshark · Wireshark-users: Re: [Wireshark-users] Comparing two pcap files for latency

[Guy Harris <guy@xxxxxxxxxxxx>]

On Jan 31, 2011, at 9:19 AM, jobhunts02@xxxxxxx wrote:

> Is there a program available that will compare two pcap files and calculate the latency of specific packets, assuming that the clocks on the two machines that created the pcap files are synchronized?  

By "calculate the latency" do you mean that the packets in question are going between two particular machines, and the two captures were done on those machines, and, for each of those packets, you want the difference between the time stamp for that packet in the capture done on the machine that sent the packet and the time stamp for that packet in the capture done on the machine that received the packet?

I don't know whether such a program exists - and the accuracy of the time delta will depend on the accuracy of the time stamps and, by default, there are a number of reasons why the time stamp might not be as accurate as you'd like (low resolution of the timer used by the OS to time-stamp the packets, delays between the point at which a packet being sent is time-stamped and the point at which the packet is put on the wire, delays between the point at which a packet is received and the point at which it's time-stamped).