Wireshark · Wireshark-dev: Re: [Wireshark-dev] ATM over Ethernet

[Alex Bennée <kernel-hacker@xxxxxxxxxx>]

On 6 November 2012 10:13, Alex Bennée <kernel-hacker@xxxxxxxxxx> wrote:
> On 5 November 2012 18:53, Guy Harris <guy@xxxxxxxxxxxx> wrote:
>> On Nov 5, 2012, at 4:14 AM, Alex Bennee <kernel-hacker@xxxxxxxxxx> wrote:
>>
>> No, you need to implement a dissector for your ATM-over-Ethernet encapsulation that repeatedly calls the ATM dissector for each cell.  Multiple cells encapsulated in an Ethernet packet is a characteristic of your encapsulation, not of ATM, so the code to handle that should be part of the dissector for your encapsulation, not the dissector for ATM.

Ahh it makes more sense now. I've attached the re-worked patch which
adds an explicit atmoe dissector which seems to work.

> Also how is the AAL encoding determined? Should I just register the
>>> handlers for the multiple AAL types and let the user decide?
>>
>> Yes.  The AAL encoding is determined by whatever AAL information is in the capture file, and I suspect that is often put there by a user explicitly configuring the capturing machine.
>
> It looks like I'll have to set a preference for that then as it's only
> really specified by the application specific VC.
>
I guess the real question is do I add options to the ATM decoder to
select AAL based on VPI/VCI?


-- 
Alex, homepage: http://www.bennee.com/~alex/
http://www.half-llama.co.uk

Attachment: 0001-Add-new-dissector-ATMoE.patch
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