On Apr 27, 2011, at 9:59 PM, Sebastian Kiesel wrote:
Hi stefano,
On Wed, Apr 27, 2011 at 11:17:33AM +0200, stefano previdi wrote:
On Apr 27, 2011, at 10:22 AM, Sebastian Kiesel wrote:
Hi,
On Wed, Apr 27, 2011 at 09:15:11AM +0800, ?????? wrote:
hi, everyone:
have the ALTO considered the use cases of wireless, which means how
to make
the selection of the peers in the wireless environment?
the ALTO protocols and procedures feature mechanisms that can be
leveraged in a mobile / wireless scenario. IMO there are two issues:
1. When a client is moving between different sections of an access
network it may have to find a new ALTO server which is able
to give guidance that is useful at the new client position.
draft-kiesel-alto-3pdisc-05, sec. 1.3 states:
o A change of the IP address at an interface invalidates the
result
of the ALTO server discovery procedure. For instance, if the IP
address assigned to a mobile host changes due to host mobility,
it
is required to run the ALTO server discovery procedure for the
new
IP address without relying on earlier gained information.
mobility is often at layer-2 and this mean you will need some other
mechanisms in order to enrich your maps/ecs with wireless-l2 derived
topology info.
I agree. But the creation of maps based on the (wireless) topology and
other {cost,distance,performance,...}-related information as well as
feeding them into the ALTO server is out of scope of the protocol
spec.
well, yes, that's what I stated in my previous email...
The paragraph above is about ALTO server discovery:
If the client notices that it has been assigned a different IP
address,
one reason may be a significant movement in the network, e.g.,
handover
from one mobility anchor to another, and therefore a new ALTO server
discovery might be required (of course, there might be other reasons
for
getting a new IP addres, but doing a new discovery then won't hurt).
Are there any networks using layer-2 mobility which are so huge,
that a
client should discover and use different ALTO servers while moving
around even though it can retain the same IP address?
in a clever implementation, the use of a particular ALTO server
is mostly dictated by the boundaries of the infra/routing domain
where the client resides. IOW: as long as you stay within the same
SP infrastructure, there shouldn't be reasons to change ALTO server.
s.
Thanks,
Sebastian
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