Subject: [mif] draft-blanchet-mif-problem-statement-00.txt

From: Tony Finch <[email-masked]>
Date: Mon, 5 Jan 2009 19:23:59 +0000

The discussion of host-scoped vs interface-scoped configuration is really
good - enlightening though not very cheerful. Perhaps another useful
example would be a server with an Ethernet interface for the public
Internet, and another for a private service network.

It seems to me that the draft mostly concentrates on things that ought to
work in the current Internet. Do you plan to extend it to include features
that should be supported in the future? If so...

The problem statement says packet forwarding is out of scope, but in
practice it is common for portable devices to act as gateways for each
other, e.g. a phone gatewaying 3G to Bluetooth for a laptop, or a laptop
acting as a WiFi base station with an Ethernet uplink. At the moment this
often relies on NAT, but ideally these ad-hoc edge networks should be able
to get proper Internet connectivity.

How do the problems relate to mobile IP? Is there any way of using
multiple interfaces to get redundancy and fail-over? If so, servers are
likely to want to provide services on multiple interfaces for reliability.
How does that affect address selection?

Can a host use multiple interfaces to get more bandwidth? Obviously yes
now by binding the local end of each socket to each interface, but that
introduces much more complexity to an area that was previously simple. Is
that complexity avoidable?

Tony.
-- 
f.anthony.n.finch  <[email-masked]>  http://dotat.at/
SOUTHEAST ICELAND: NORTHERLY OR NORTHWESTERLY, VEERING EASTERLY 3 OR 4,
INCREASING 5 AT TIMES. MODERATE OR ROUGH. RAIN OR SHOWERS, WINTRY IN NORTH.
MODERATE OR GOOD, OCCASIONALLY POOR.
_______________________________________________
mif mailing list
[email-masked]
https://www.ietf.org/mailman/listinfo/mif

---

From: Marc Blanchet <[email-masked]>
Date: Mon, 05 Jan 2009 14:41:17 -0500

Tony Finch a écrit :
> work in the current Internet. 

- another draft is in the works on documenting how current
implementations work. Many of them just take the last configuration info
(i.e. last dhcp answer just rewrite everything).
- it does not work, that is why we are documenting it and see if there
is enough interest to make a wg or standard or best practice or ...
- my own personal experience is daily with this problem...

> Do you plan to extend it to include features
> The problem statement says packet forwarding is out of scope,

yes. see below.

> but in

The document does not discuss packet forwarding. That does not mean it
could not be done. it is out of scope because packet forwarding is _not_
the purpose of mif. a device which has a mif problem may or may not do
packet forwarding, it does not really matter.

> 
> How do the problems relate to mobile IP? 

if the mobile IP is implemented as an additional interface, then it does.

> Is there any way of using
> multiple interfaces to get redundancy and fail-over?

in my book, failover is where there are 2 interfaces, and only one is
active at a given time. therefore, it does not apply to mif.

> If so, servers are

-- 
=========
IPv6 book: Migrating to IPv6, Wiley, 2006. http://www.ipv6book.ca
Stun/Turn server for VoIP NAT-FW traversal: http://numb.viagenie.ca

---

From: "[email-masked]" <[email-masked]>
Date: Thu, 8 Jan 2009 16:45:18 +0200

Hi,

>-----Original Message-----
>From: [email-masked] [mailto:[email-masked]] On 
>Behalf Of ext Tony Finch
>Sent: 05 January, 2009 21:24
>To: [email-masked]
>Subject: [mif] draft-blanchet-mif-problem-statement-00.txt
>
>Can a host use multiple interfaces to get more bandwidth? 
>Obviously yes now by binding the local end of each socket to 
>each interface, but that introduces much more complexity to an 
>area that was previously simple. Is that complexity avoidable?

This is probably not in mif scope. There's some interesting work ongoing
on having multipath support on transpor layer (multipath TCP):
http://www.ietf.org/proceedings/08jul/slides/tsvarea-2.pdf

Maybe mif could help to select the network interfaces that are usable
for this kind of use (e.g. if host has two network interfaces for public
Internet and one for private Intranet).

Also as was mentioned already Mext is working on MONAMI and multiple
CoA, but additionally similar approaches might be possible on
netlmm-scope. From mif point of view application running in a host
utilizing host based IP mobility there is one network interface with CoA
and one network interface with HoA to choose from. On network based
mobility case there's just the (virtual) network interface with "HoA",
and that network interface hides from mif the possible usage of parallel
physical network interfaces.

Best regards,

	Teemu