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Ethereal-dev: Re: [Ethereal-dev] ATM code : testing

Note: This archive is from the project's previous web site, ethereal.com. This list is no longer active.

From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Mon, 4 Aug 2003 10:20:46 -0700
On Mon, Aug 04, 2003 at 06:08:22PM +0530, Sunil Kumar wrote:
>  How the testing of ATM part of ethereal has been done ?
>  
>  1. Is it using capture files from some sniffers ( This would be non-real
>  time)

Yes.

>  2. real time capture using system with ATM NIC's connectied to CO side
>  switch/router ?

I forget whether I tried capturing on Solaris with Ethereal, or just
tried it with tcpdump and having Ethereal read the captures, but that
doesn't matter, as both tcpdump and Ethereal use libpcap to capture
packets, so that's really a libpcap issue.

Besides, real-time captures are dissected by, well, reading the capture
file from a sniffer; in the case of a real-time capture, that capture
happens to be the one that Ethereal is writing to, but that doesn't make
a difference to the dissection.

Note that whether Ethereal can capture "raw ATM", and thus on whether
you'll see the various types of ATM traffic that the ATM dissector in
packet-atm.c could dissect, depends not on Ethereal but on libpcap, the
library it uses to capture packets, and on the underlying capture
mechanism that libpcap uses.  It thus depends on the OS on which you're
running.

>  I see that packet-atm mentions about ATM LANE , RFC1483 , OAM , ILMI ,
>  AAL1 , AAL3_4 does all these are supported fully in ethereal ? 

I guess it depends on what you mean by "fully".  We haven't put in stuff
to decode all of LE Control frames, for example, and we don't support
token-ring LANE, just Ethernet LANE.  ILMI is just dissected as
SNMP-over-ATM; we don't supply, for example, MIBs for it.  We don't
dissect the function-specific information in OAM cells, nor do we make
any attempt to dissect the payload of AAL1 or AAL3/4 cells.

>  how were these tested

By reading capture files and comparing the way they're dissected by
Ethereal with the way they're dissected by the application that captured
them, if that application isn't Ethereal and is available (or if a
printout of the way that application dissected them is available), or
just by looking at the way Ethereal dissected them, if they were
captured by Ethereal or if we didn't know how the application dissected
them.