On Oct 14, 2019, at 12:10 PM, Nick Kelsey <ni...@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?
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