SUBSCRIBE needs Num Parameters field

[martinduke]

if there are going to be "track request parameters" in subscribe, we need a way of indicating that it is present. Presumably via a NumParameters field.

[afrind]

Individual Comment:

Can you use the message length? eg: if there are any bytes remaining after parsing required fields, parse another param?

[martinduke]

There is no message length, right? Or did that come back?

[afrind]

You are right, there's no message length, and this looks like an oversight or mis-merge? Can you make a PR to add Num Parameters, and perhaps the group will agree to set the interop target to draft-02 + that PR?

[fluffy]

Reading RFC 9000 section 1.3, I thought the syuntax "x (L) ..." meant we would have zero or more and it included the counter of how many in the encoding. I could be missing the boat here but not seeing why we have the number twice on the wire. I am always confused about the syntax used in RFC 9000 so I probably confused here but someone walk me through it.

[martinduke]

Yes, some of these 9000 formats are very confusing, and I had to look again.

The format in the MOQT draft is 'Parameters (..) ...'. I can't really parse the definitions in 1.3, but this notation occurs in two places in 9000. One is ACK ranges, and ACKs have an explicit ack_range_count field.

In any case, there are several other places (SETUP, ANNOUNCE) where we have the field listed there. So:

1. I think the notation is wrong
2. Even if it isn't we should be consistent
3. Even if it isn't, it impedes understanding and an explicit listing would be better.