[EMAIL PROTECTED] wrote:

> You mentioned that dissector for LAPB & FrameRelay already exist. I do not
> see those in my version of WireShark (I am running it under WindowsXP).

"Do not see" in what sense?

> Do I have to download any additional software ?

No.  See epan/dissectors/packet-lapb.c and epan/dissectors/packet-fr.c.

> Now if I were to do a similar test on our HDLC ports configured for X.25 or
> FrameRelay, what information would  I have to put the file header to tell
> WireSharek that this is X.25 or FrameRelay capture ?
> I would assume that the answer has to do with the "network" field of the
> "pcap_hdr_t" structure, but ... what do I have to populate it with ? Can it
> be done at all ?

For Frame Relay, yes; the value is 107.

For LAPB, currently, no.  You'd have to ask [email protected] 
for a value.  Note that you should indicate whether the packets in that 
format start with the address field in the LAPB header or whether they 
also include a field giving an indication of whether the packet was 
received or sent (unfortunately, libpcap format doesn't have a direction 
field in the per-packet header).

> Another issue has to do with the requirement to capture traffic from
> multiple cards/ports (each data comm card in a chassis has 8 ports) to a
> single "capture entity". One of the cards in the chassis is a "system
> management card", it runs Linux (this is where WireShark would run). We are
> thinking/considering making changes to the libpcap library on this card, to
> "expose" all the data comm port on the other cards as "local interfaces" to
> WireShark, this way be able to capture traffic from multiple ports at the
> same time.

Would that be a single stream of packets (i.e., a single pcap_t opened 
by pcap_open_live())?  If so, you'd also want to add a port number in 
front of the LAPB header, along with possibly adding a direction flag.

If the different cards have different link-layer types, it gets more 
complicated, in that you'd have to put the link-layer type of each 
packet in the per-packet header - or adopt pcap-NG format:

        http://www.winpcap.org/ntar/draft/PCAP-DumpFileFormat.html

for which support would have to be added in Wiretap (which would involve 
Wiretap API changes).

> In the process part of the libpcap library would have to be
> ported to the data comm cards to support run-time filtering ... etc.

E.g., adding the BPF interpreter?  The implementation in libpcap is 
BSD-licensed; Linux includes a GPLed implementation.
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