Wireshark-users: Re: [Wireshark-users] Checksum incorrect on the IP layer on RTP packets
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]"
<[email protected]> wrote:
> Have a look at TCP checksum offloading :-)
> 
> (http://wiki.wireshark.org/TCP_checksum_offload)
> 
>  
> 
> Roger
> 
>  
> 
> From: [email protected]
> [mailto:[email protected]] 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.