Wireshark mailing list archives
Re: IP Error (Header Checksum) can effect Jitter calculation ?
From: Martin Visser <martinvisser99 () gmail com>
Date: Tue, 1 Jun 2010 21:31:40 +1000
The most likely cause of checksum "errors" when capturing packets with Wireshark is the driver/NIC combination of the machine you are doing this with. Many NICs are able to offload this function from the main CPU, improving performance. The normal network driver knows to ignore the checksum, not doing the work, and assumes it is being handled correctly by the NIC. Wireshark however calculates the checksum by default and matches it with what is in the packet, reporting the error falsely. It is unlikely you will receive real errors with Wireshark, as the CRC32 checks by the NIC and switch will drop errored packets and you won't see them. So you are best off turning this feature off in the appropriate preferences section for each protocol. See http://www.wireshark.org/docs/wsug_html_chunked/ChAdvChecksums.html for more details. Regards, Martin MartinVisser99 () gmail com On Tue, Jun 1, 2010 at 4:55 PM, capricorn 80 <cool_capricorn80 () hotmail com>wrote:
Hi! In IP section Header checksum: 0x0000 [incorrect, should be 0x5a54] Bad : True Regards, ------------------------------ Date: Mon, 31 May 2010 12:27:53 +1000 From: martinvisser99 () gmail com To: wireshark-users () wireshark org Subject: Re: [Wireshark-users] IP Error (Header Checksum) can effect Jitter calculation ? Provided the packet is identified as RTP, it should be included. What errors are you referring to? Regards, Martin MartinVisser99 () gmail com On Sun, May 30, 2010 at 2:53 AM, capricorn 80 < cool_capricorn80 () hotmail com> wrote: Hi! I have taken few trace of jitter using wireshark. In one of the trace i can see some error in Internet protocl sections. Does that effect the jitter calculation ? Regards, Sajid ------------------------------ Hotmail: Trusted email with powerful SPAM protection. Sign up now.<https://signup.live.com/signup.aspx?id=60969> ___________________________________________________________________________ Sent via: Wireshark-users mailing list <wireshark-users () wireshark org> Archives: http://www.wireshark.org/lists/wireshark-users Unsubscribe: https://wireshark.org/mailman/options/wireshark-users mailto:wireshark-users-request () wireshark org ?subject=unsubscribe ------------------------------ Hotmail: Powerful Free email with security by Microsoft. Get it now.<https://signup.live.com/signup.aspx?id=60969> ___________________________________________________________________________ Sent via: Wireshark-users mailing list <wireshark-users () wireshark org> Archives: http://www.wireshark.org/lists/wireshark-users Unsubscribe: https://wireshark.org/mailman/options/wireshark-users mailto:wireshark-users-request () wireshark org ?subject=unsubscribe
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Current thread:
- Re: IP Error (Header Checksum) can effect Jitter calculation ? capricorn 80 (Jun 01)
- Re: IP Error (Header Checksum) can effect Jitter calculation ? Martin Visser (Jun 01)
- Re: IP Error (Header Checksum) can effect Jitter calculation ? capricorn 80 (Jun 01)
- Re: IP Error (Header Checksum) can effect Jitter calculation ? Martin Visser (Jun 01)
- Re: IP Error (Header Checksum) can effect Jitter calculation ? capricorn 80 (Jun 01)
- Re: IP Error (Header Checksum) can effect Jitter calculation ? Martin Visser (Jun 01)