tcpdump mailing list archives
Re: Linktype allocation for ATSC link layer protocol
From: Guy Harris <gharris () sonic net>
Date: Mon, 14 Oct 2019 12:22:59 -0700
On Oct 14, 2019, at 12:10 PM, Nick Kelsey <nickk () silicondust com> wrote:
ATSC 3.0 includes a new link layer protocol known as ALP (ATSC Link-layer protocol).So the first two octets of the packet data contain the Base Header? That appears to be a 16-bit header; in a capture, in what order are the bytes of the Base Header, and in what order are the bit fields? The same applies to other fields.There are a few different packet formats...
But they all have the Base Header, and that header has: 3 bits of packet type; 1 bit of payload configuration; 1 bit of: header mode, if the payload configuration bit is 0; segmentation/concatenation, if the payload configuration bit is 1; 11 bits of length; for a total of 16 bits, right? If so, in a capture file: 1) the Base Header has 2 octets - in what order in the file are the two octets? 2) in what order are the bit fields? For example, does the first octet of a packet contain: 3 bits of packet type in its upper 3 bits; 1 bit of payload configuration in the next lower bit; 1 bit of header mode or of segmentation/concatenation in the next lower bit; the uppermost 3 bits of length in the lowest 3 bits; and does the second octet contain the lowermost 8 bits of length? _______________________________________________ tcpdump-workers mailing list tcpdump-workers () lists tcpdump org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
Current thread:
- Linktype allocation for ATSC link layer protocol Nick Kelsey (Oct 14)
- Re: Linktype allocation for ATSC link layer protocol Guy Harris (Oct 14)
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- Re: Linktype allocation for ATSC link layer protocol Nick Kelsey (Oct 14)
- Re: Linktype allocation for ATSC link layer protocol Guy Harris (Oct 14)
- Re: Linktype allocation for ATSC link layer protocol Nick Kelsey (Oct 14)
- Re: Linktype allocation for ATSC link layer protocol Nick Kelsey via tcpdump-workers (Oct 17)
- Re: Linktype allocation for ATSC link layer protocol Nick Kelsey (Oct 14)