Wireshark-dev: Re: [Wireshark-dev] X.25, LAPB, PLP Decoding
From: Guy Harris <[email protected]>
Date: Mon, 18 Jun 2007 11:13:46 -0700
[email protected] wrote:

I think that I should define proprietary “DLT_LAPB” value and do whatever necessary steps in wtap (WireShark) in order to recognize my DLT_LAPB type form libpcap file header. After that I should be able to see LAPB frames and PLP packets in the WireShark.
Nobody should ever define, by themselves, a proprietary DLT_ value.  If 
you just pick some number to assign to that DLT_ name, there is a chance 
that tcpdump.org will assign that value to an official DLT_ in the 
future, and, if that happens, Wireshark will almost certainly be 
modified to interpret that value as that DLT_.  That would mean your 
changes would have to *override* that.
The alternatives are:

1) ask [email protected] to add an *official* DLT_LAPB and assign a value to it, which means that Wiretap could be changed to that the *standard* version will decode that DLT_ value as LAPB (so you wouldn't need to maintain your own version of Wireshark);
	2) use one of the DLT_USERn values.

I would recommend alternative 1.