Huge thanks to our Platinum Members Endace and LiveAction,
and our Silver Member Veeam, for supporting the Wireshark Foundation and project.

Wireshark-users: Re: [Wireshark-users] Checksum incorrect on the IP layer on RTP packets

From: Boaz Galil <boaz20@xxxxxxxxx>
Date: Wed, 12 Aug 2009 18:21:31 +0300
 
Guys,
 
I am familiar with TCP checksum offloading but I am talking about  RTP (over UDP).  and the checksum incorrect is on the level of the IP layer not the UDP level....
 


 
On Wed, Aug 12, 2009 at 6:07 PM, Jaap Keuter <jaap.keuter@xxxxxxxxx> wrote:
Hi Roger,

Sorry, but he's talking about IP checksums and RTP, which is over UDP, not
TCP.
But still the concept is the same.

Thanx,
Jaap

On Wed, 12 Aug 2009 07:46:08 -0700, "Wynns, Roger [OXFORD]"
<RWynns@xxxxxxxxxxx> wrote:
> Have a look at TCP checksum offloading :-)
>
> (http://wiki.wireshark.org/TCP_checksum_offload)
>
>
>
> Roger
>
>
>
> From: wireshark-users-bounces@xxxxxxxxxxxxx
> [mailto:wireshark-users-bounces@xxxxxxxxxxxxx] On Behalf Of Boaz Galil
> Sent: Wednesday, August 12, 2009 9:37 AM
> To: Community support list for Wireshark
> Subject: [Wireshark-users] Checksum incorrect on the IP layer on RTP
> packets
>
>
>
>
>
>
> Checksum error in the IP layer on RTP packet
>
>
>
> Dear experts,
>
> Please consider the following scenario:
>
> Computer A streams RTP packets to Computer B.
>
> I have set up wire shark on both computer A and computer B.    The
> packet capture that I collected from computer A  (filtered for RTP
> packets) showed me that each packet has "incorrect checksum" on the IP
> level on all the RTP packets.  The packet capture that I collected from
> computer B showed me "correct checksum" on all the RTP packets.
>
> Can someone please explain me what I am observing here and how could it
> be possible that on one side the checksum is Incorrect (the sender side)
> and on the second side (the receiver side) the checksum is correct?
>
>
>
> Thanks in advance,
>
> Boaz Galil.
___________________________________________________________________________
Sent via:    Wireshark-users mailing list <wireshark-users@xxxxxxxxxxxxx>
Archives:    http://www.wireshark.org/lists/wireshark-users
Unsubscribe: https://wireshark.org/mailman/options/wireshark-users
            mailto:wireshark-users-request@xxxxxxxxxxxxx?subject=unsubscribe



--
Boaz.