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Re: [Captive-portals] Feedback requested: Charter text.

A couple of discussion points, since you asked:

"Captive Portal" is a term that seems to be specifically about getting access to the network.
Could this technology embrace other forms of alerts, such as tornado/tsunami/fire/toxic-spill ?
In other words, the ability of the network to interrupt the user with, 
"I need your eyes on this information, right now"

On an unrelated note, should probably allow devices without operators or screens (IoT devices) to fulfill CP requirements.
Hence, not just about browsers rendering HTML to humans, but any kind of client.

Although the proposed charter doesn't say it, some discussion seems to indicate this should be a link-layer 
problem. I.e., a matter for DHCP and the first-hop router. I'd like to see this posed as an internet-layer 
problem, hence applicable to all forms of internet access, and made enforceable by any forwarding device 
along the path. As a simple example, a device behind a NAT may need to receive a captive-portal alert from
an enforcement point on the other side of the NAT.

I don't know if any of my points warrant changes to the proposed charter. But if the above are to be
specifically excluded, it's probably worth saying so.


-----Original Message-----
From: Captive-portals [mailto:[email protected]] On Behalf Of Warren Kumari
Sent: Tuesday, June 23, 2015 2:26 PM
To: [email protected]
Subject: [Captive-portals] Feedback requested: Charter text.

Hi all,

We have a BoF scheduled for the IETF in Prague.

We would like to get a discussion going on some *strawman* charter text.


Captive Portals are used to restrict access to a network until users
have purchased access, or accepted Acceptable Use Polices (AUP).
They accomplish this by intercepting connections from unauthenticated
clients, redirecting them to an authentication server, and then
granting access (if satisfied). By developing a standard set of
Captive Portal interactions (including simple ways for clients to
discover and interact with CPs), we will significantly improve the CP
user experience, increase security, and simply the CP interceptions.
This will increase the user completion rate, increase the CP
interception reliability, and decrease the implementation complexity
and cost.

Many of the interception techniques are very similar to
man-in-the-middle attacks, and, as clients become more secure, are
increasingly ineffective, leading to a poor user experience. Many of
the captive portals require a web browser to interact with the
authentication system, and may require that the user disconnects any
VPNs, browses to a non-HTTPs site, or similar. In addition, there is
no standard way to discover the existence of the captive portal, when
the captive portal has been satisfied, and how much time remains
before the captive portal restricts access again.

The Captive Portal (CAPPORT) Working Group will address these (and
related issues) by defining a standard mechanism for clients to
interact with Captive Portals, including how to connect to the captive
portal and how to communicate with it to obtain status information
such as remaining access time, purchased bandwith class, etc.

This working group will seek participation and input from browser /
operating system vendors, captive portal developers and operators.
One of the known challenges is that some captive portal operators may
not want to use a standard interaction protocol, preferring to perform
more intrusive interception and interactions. We are hoping that the
benefits to CP standardization outlined here are sufficient to not
only encourage input from CP developers and operators, but also aid in

TDB: Initial problem statement / use case document [0]
TBD: Initial terminology document [1]
TBD: Initial portal interaction document (perhaps based upon
http://coova.org/CoovaChilli/JSON ?)
TBD: Extended portal interaction document (for systems without browsers)

[ Each of these milestones is actually Initial draft -> WGLC -> IESG, etc ]

[0]: Primarily to ensure that we are understand what we are trying to
accomplish / working to the same goal. This may or may not become an
[1]:  We have already discovered that we have issues here - what's the
webpage after the CP has granted access called? What's the "lease"
time called -- different vendors have different names for things.
Crappy first pass:


I don't think the execution is relevant when it was obviously a bad
idea in the first place.
This is like putting rabid weasels in your pants, and later expressing
regret at having chosen those particular rabid weasels and that pair
of pants.

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