Re: [Captive-portals] Use Case: "Carrier Grade Captive Portal"

[Erik Kline <[e-mail]>]

On 19 May 2017 at 05:33, Vincent van Dam <[e-mail]> wrote:

> > > The separation of "configuration" and "notification" is by design.
>
> > That might be a design error.  Notification is done by the provider, but
> configuration (how to react
> > on e.g. icmp unreachable) is up to the enduser. The provider cannot (and
> will not) configure
> > any customer's client device. Maybe the CPE can be (pre-)configured
> (cable-modem/dsl-router) but
> > not the home-PC. How do I tell the home-PC to open up a specific URL
> when capport
> > detection gets activated (if it would exist)?
>
> The url is not included in the icmp payload as it would introduce a ddos
> security risk.
>
> Good point. In the home-network realm, advertising the url using dhcp
> would also require the CPE to propagate this url to the home network. I
> agree this would be challenging.
>
> Maybe we can learn/inspire from the “Proposals to discover Provisioning
> Domains” draft that was shared with this wg earlier this year (
> https://tools.ietf.org/html/draft-bruneau-pvd-00; note it has been
> replaced). This draft tackles a similar problem, discovery of the
> configuration url. In this draft the authors define in chapter 3, they
> could retrieve what they required by using the “Fully Qualified Domain Name
> which belongs to the network operator” (chapter 3). And later (4.2) they
> specify a fixed location where this information can be fetched. Maybe we
> can use a similar approach. If the UE doesn’t have the url as it would have
> been advertised in the dhcp, retrieve some config from a fixed url based on
> the fqdn that belongs to the operator?
>

That necessitates a UE-side change.  Learning a captive portal URL by means
other than DHCP (which would require router changes as well to somehow
propagate the information into a multi-hop home) certainly does seem worth
considering.

But I'm assuming that operationally HTTP intercept and redirection will
have to persist, until un-upgraded UEs are somehow not worth the effort.