[e2e] Re: Control traffic: how many % of payload traffic?

[Michael Welzl]

Hi,


> Does it take that much more control traffic for a Video Stream than
> a Voice Stream? If you model the restriction based on a ratio that
> is fixed regardless of Media type, I think you'll guarantee wasted
bandwidth.
>
> Another example, does an MPEG4 media flow require more control
> traffic/packets than an MPEG2 flow? And are the proportional?

I see - I need to be more specific about what I'm doing here.
I am designing an ABR-like Explicit Rate signaling mechanism for adaptive
multimedia flows (maybe also for reliable data traffic in the future);
and I am trying to come up with a rule to restrict the amount of control
traffic (which would be the equivalent of ATM RM cells).

The goal is to provide a TCP-friendly service with a very low packet loss
ratio. Theoretically, it makes sense to regard the relationship between
media type / necessary amount of control traffic as a trade-off (how low
does the packet loss ratio need to be vs. scalability); but I think
it would be too complicated to incorporate this into the mechanism spec.

I would rather go for the smallest possible packet loss ratio - which
could be achieved by sending a control packet every RTT, but this may
not scale well. So I need an additional general rule.

Cheers,
Michael