RE: new draft on IPv6 CPE router available for review

[<teemu.savolainen@nokia.com>]

Hi,

>So, my vision of "CPE" is the same as the authors of the draft 
>that started the discussion, a "CPE router". These are for me 
>the same. A host is not a router (difference is that a router 
>does IP forwarding, a host does not).

If the forwarding is the key differentiator, then isn't e.g. "host"
computers running Microsoft Windows, Apple OS/X, and even certain mobile
phones, also "routers" as they support "sharing of the network
connection", which means forwarding packets from the uplink connection
to local area network - possibly implementing DHCPv4 server, to allocate
private IPv4 addresses for LAN, and NAT for address translation between
LAN and uplink connection?

If the "CPE router" would be defined as something that implements and
executes routing protocols, has MIBs, is fully controllable by ISP then
these hosts would not fit into that category. 

Anyhow, in my mind a "host" is not so much of a name for a category of
devices, but rather a behavioral pattern of a node. At any given moment
a node can start to behave as a "router" (if that is defined only as
doing packet forwarding). For a network the node may still look like a
"host", if the node does this transparently for the network (i.e. with
help of NAT). 

>> This CPE may be a router or a host. there is no difference 
>between two 
>> of those from ISP point of view.
>
>Yes, and I think these need two different services.
....
>Well, I don't like the idea of end users connecting IPv6 only 
>hosts directly to the ISP network, I want the customer to be 
>required to have a router, and I don't want the customer to 
>have the possibility to source packets in core IP space, and I 
>don't want ISP routers to have IPs in the customer IP range.

I did not think that was the idea either? If the end hosts would use
DHCPv6 PD, would that be an act of sourcing packets to IP core? If so,
could the delegating DHCPv6 server locate somewhere where "hosts" could
safely (from ISP point of view) talk?

The talking to ISP core is one differentiator, then we might(?) have:

(1) CPE router:
- allowed to directly source packets to ISP core
[host]---[CPE router]---[ISP]---[Internet]

(2) "Host router":
- not able to directly source packets to ISP core, but still able to
forward packets and use DHCPv6 PD
[host]---[host router]---[CPE router/access
concentrator]---[ISP]---[Internet]

The (1) case is what you are aiming I believe, and the (2) is what I'm
trying to describe.

An example of case (1) would be a DSL box at home/small office, and an
example of case (2) would be a cellular device that:
- connects with point-to-point link to operator's access concentrator
(e.g. GGSN), and gets a /64 prefix for itself (SLAAC)
- uses DHCPv6 PD to get more prefixes, and announces these prefixes to
LAN
- possibly implements DHCPv6 relay in order to enable other devices in
LAN to utilize DHCPv6 PD as well

Best regards,

	Teemu