Re: AD Evaluation comments on draft-ietf-rmt-bb-tfmcc-06

Hi,

I have removed all items where the proposed fixes are fine. I think the 
proposed changes for ts_r, ts_i' etc are good and will result

Joerg Widmer wrote:
> 
>> 6. Section 3.6: I am missing any definition on when slow start may be
>> used. What are the prerequisite for applying the slow start mechanism?
> 
> As written in 3.6, "Slowstart is terminated as soon as any one of the
> receivers experiences its first packet loss". We kept TFMCC congestion 
> control as similar to TFRC as possible, so all this is more or less as 
> in RFC 3448. For multicast, a false slowstart during severe congestion 
> can cause considerable harm and we therefore opted to only allow it at 
> the start of the session.

Okay, it is clear when you leave slow start. What isn't clear is the 
what the requirements are for entering slow start. In my opinion the 
draft need some text explaining when a sender is allowed to use slow start.

> 
>> 8. Section 5.5: Could anyone please explain why the history 
>> discounting for I_tot1 does only include the DF_i and not also the DF 
>> value?
> 
> The DF is used to give more weight to the first interval I_0 only if the 
> first interval is included. For calculating p, we compare the avg. 
> interval size with I_0 to that without it, and for the latter DF has to 
> be omitted. (In fact, we could also multiply I and W by DF which would 
> do nothing since p = W/I.)
> 

Thanks, I think I understand.

> I'll prepare and updated version as soon as possible in the coming 1-2
> weeks. Please let me know if you have any comments concerning the 
> proposed changes. What exactly are the next steps? Do I need to submit 
> the changes directly to you or is a draft submission necessary first?
> 

Please submit a new draft. I will check the actual changes before 
forwarding the draft to IETF last call.

cheers

Magnus Westerlund

Multimedia Technologies, Ericsson Research EAB/TVA/A
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