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