On Nov 30, 2017, at 1:42 AM, Anton Glukhov <anton.a.gluk...@gmail.com> wrote:

> I've been working for IEEE802.1Qbu Frame Preemption Protocol and now it's 
> part of TSN set of protocols. I would like to propose the new link type and 
> sent this proposal to tcpdump-workers@lists.tcpdump.org, but unfortunately no 
> response.

It's hard to respond to a message that was never delivered. :-)

If you're not subscribed to tcpdump-workers, a message you send to the list is 
put in a moderation queue; your message might be in the queue, and the 
moderator might not have gotten around to releasing it.  (I don't know how to 
manage the moderation queue; I found an e-mail message indicating that I'd 
received the moderation password, but I couldn't find anything on how 
moderation was done, and have long since forgotten both the password and the 
procedure for releasing messages.)

It's not a very busy list, so you won't get flooded by e-mail if you subscribe. 
 According to the archives:

        http://seclists.org/tcpdump/

in the busiest 3-month period since 2002, 377 messages arrived, for an average 
of a little more than 4 messages per day.  Recently, it's been more like 30-60 
messages in a 3-month period, which is less than one message per day.

Instructions on subscribing can be found at

        http://www.tcpdump.org/#mailing-lists

I"m CCing the tcpdump-workers list.

> I'm working for Frame Preemption Protocol(IEEE 802.1Qbu), which is part of 
> Time-Sensitive Networking(TSN) set of standards. The protocol has very 
> interesting extension of standard Ethernet frame and I'd like to propose to 
> add the new link-layer type. Here are the reasons:
> - protocol uses non-standard ethernet preamble, user must see the type of 
> frame/fragment

LINKTYPE_ETHERNET frames don't include the preamble, so a preempting frame with 
a different preamble would look, in an LINKTYPE_ETHERNET capture, exactly like 
a non-preempting frame.

Are you saying that you want a variant of LINKTYPE_ETHERNET, in which the MAC 
header is preceded by something that indicates whether this is a regular or a 
preempting frame, so that captures with this link-layer header type can include 
both regular and preempting frames?

> - protocol uses specific CRC sum. It's called mCRC and depends on preamble, 
> which means the type of frame/fragment

LINKTYPE_ETHERNET may, but aren't guaranteed to, include the CRC; to properly 
check the CRC, the additional metadata giving the frame type would be required, 
so it knows whether it's a regular or modified CRC.
_______________________________________________
tcpdump-workers mailing list
tcpdump-workers@lists.tcpdump.org
https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers

Reply via email to