On Fri, 7 Sep 2007, Michael Watterson wrote:
> Mobile internet used as fixed Internet is going to seriously wreck O2, 3 and
> Even so called "no contention " packages are contended as it is
> assumed that if you aggregtate 1000 users (say) a maximum amount of
> traffice is much less than sum num Users * package per user.
Well, standard TCP pretty much guarantees this. Routers need to apply
back-pressure in some way (e.g. WRED) if you want to see anthing
approaching link bandwidth..
> P2P routing at exchange level would oly save maybe less than 1% of
Why? A couple of k DSL links / exchange ought to be typical, no?
Customers' P2P apps /could/ easily (if the network actually made it
*possible*), prefer to get files from closer-TTL peers.
For near-broadcast viewing (i.e. popular stuff, i.e. Corrie), you
could have half the exchange customers get it from the internet and
the other half get it from exchange customers. I.e. your backhaul
demand becomes n/2, rather than n. Only linear saving, but still
That's a worst case, presuming all the corrie fans click to watch at
about same time - so no P2P client will ever serve more than one
copy, and you get least savings. But that case is better served by
multicast. For 'on-demand', where viewing of some show is spread out,
you could get much better caching and re-use.
But this requires:
- IP layer visibility of those links
- the DSL up/down band split to be more symmetrical
It also requires we stop caring about Eircom having to provide
whole-sale DSL. ;) (But wholesale reselling seem, as you say and as I
argued to Thomas (not for the first time), so perhaps that'll not
matter too long more). ;)
> If P2P, esp TV services that use it and people don't
> realise it is P2P, replaced Broadcast TV, then 10x as much backhaul
> is needed.
Given todays topologies, yes.
If the ISPs really are worried about P2P and backhaul bandwidth (you
think it's a problem, Thomas sort of mentioned it was a problem, in
between saying there were no problems), then they need to start
changing their networks *now*, ideally, cause it'll take the apps a
year or two to really make use of new network conditions.
However, historically, ISPs (telco-rooted ones particularly) are
incapable of anything but reactionary change. So..
This is a very expensive thing. ISPs that have not
> built their own backhaul networks will go to the wall.
> So basically if IPTV replaced Broadcast TV we are looking at a
> basic Broadband costing 200 Euro a month for it to work.
It'll only cost that if ISPs refuse to change their networks. If ISPs
do not, and they must start charging 200pm then they'll be vulnerable
to any player who does change (cable ISPs would have it easiest i
> and ban P2P for TV.
You're not getting that pony ;).
Paul Jakma paul at clubi.iepaul at jakma.org Key ID: 64A2FF6A
Take what you can use and let the rest go by.
-- Ken Kesey
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