Re: [Ethereal-users] Decoding raw MTP3 packets in pcap format

[Guy Harris <guy@xxxxxxxxxxxx>]

On Oct 2, 2006, at 12:58 PM, Keith Fleming wrote:

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> I have taken some raw SS7 MTP3 data from our application and have  
> converted it to pcap format. Ethereal correctly sees this file’s  
> contents but of course it is looking at it as if it was Ethernet.
It is?  That's not an "of course", it's the result of giving the pcap- 
format file a file header with a link-layer type of DLT_EN10MB (1); a  
different link-layer type would result in a different interpretation.
> It is MTP3 data, starting with the SIO octet, then the two 24 bit  
> point codes, then the SLS, etc.
>
> Is it possible to tell ethereal, “interpret this as MTP3 and don’t  
> worry about there not being any link-level (or lower) data”
In this case, yes; there's a link-layer type of DLT_MTP3 for exactly  
that purpose.  It has the value 141.  You'd need to create your file  
with a link-layer type value of 141 rather than 1.

As per the note added to your message at the top by the Ethereal  
mailing list software, this would work with Wireshark as well.