Re: GSE IDs [Re: IETF multihoming powder: just add IPv6 and stir]

[marcelo bagnulo <marcelo@it.uc3m.es>]

Hi,

> But I think we should revisit this when there is an actual proposal 
> that adds extra headers to packets because only then we'll be able to 
> see how this helps us and how it hurts us.


Well, using MIPv6 could be one of such proposals (there are some issues
to solve) but still can be useful to quantify the amount of overhead
involved.
Regards, marcelo

> Finally, I want to warn everyone that there is a very dangerous "who 
> cares about the overhead" attitude in some circles. (Not just IETF, but 
> also IEEE and others.) I did some calculations on VoIP over IPsec and 
> it turns out that even with a factor 4 compression of the data, the 
> total number of bits used by this is larger than regular TDM for voice. 
> Don't forget we have more than 5 layers, if every one of those adds 3% 
> overhead, that's 16% total. If they all do 5% it's 28% and if they all 
> do 10% it's no less than 61%. It adds up very quickly. A good example 
> of what can happen hee is 802.11g that has a 54 Mbps bitrate but 
> delivers little more than 20 Mbps. (But that's partially because of 
> some radio stuff obviously.)
-- 
marcelo bagnulo <marcelo@it.uc3m.es>
uc3m