Authority to Citizen Alert (ATOCA)

It took a long time to finish the charter discussions in response to the “Authority to Citizen Alert (ATOCA)” BOF. In any case, here is the charter text we came up with and the ADs are now tasked with the job of finding chairs to form a working group.

Authority to Citizen Alert (ATOCA)

There are a variety of mechanisms that authorities have available to notify citizens and visitors during emergency events. Traditionally, they have done so with broadcast networks (radio and television). For commercial mobile devices, broadcasting services such as the Public Warning System (PWS), the Earthquake and Tsunami Warning System (ETWS), and the Commercial Mobile Alert System (CMAS) are standardized and are in various stages of deployment.  The Internet provides another way for authority-to-citizen alerts to be sent, but
it also presents new challenges. While there are some existing
layer 2 mechanisms for delivering alerts, the work in this group
focuses on delivering alerts to IP endpoints only.

The general message pattern that this group is intended to address is the sending of alerts from a set of pre-authorized agents (e.g.,
governmental agencies) to a large population without impacting
layer 2 networks (e.g. causing congestion or denial of service).

The goal of this group is not to specify how originators of alerts
obtain authorization, but rather how an ATOCA system can verify
authorization and deliver messages to the intended recipients. A
critical element of the work are the mechanisms that assure that
only those pre-authorized agents can send alerts via ATOCA, through an interface to authorized alert distribution networks
(e.g., iPAWS/DM-Open in the U.S.).

The ATOCA effort is differentiated from and is not intended to
replace other alerting mechanisms (e.g., PWS, CMAS, ETWS), as the recipients of ATOCA alerts are the wide range of devices connected to the Internet and various private IP networks, which humans may have “at hand” to get such events, as well as automatons who may take action based on the alerts. This implies that the content of the alert contains some information, which is intended to be consumed by humans, and some which is intended to be consumed by automatons.

Ideally, the alerts would contain, or refer to media other than text
media (e.g., audio and/or video). The initial work in the group is
focused on small messages, which may be mechanically rendered by the device in other forms (text to speech for example). Future work in the group may investigate rich media.

In situations of a major emergency there could be scenarios
where there are multiple alerts generated that may require that a
priority mechanism (defined by alert originator policy) has to be
used. The work on a resource priority mechanism is out of scope of
the initial charter, but may be revisited at a later date.

Which devices should get alerts is primarily driven by location.
The first set of recipients that must be catered for are those
within the area identified by the alert originator to be affected
by the emergency event.  In many jurisdictions, there are regulations that define whether recipients/devices within the affected area have opt-in or opt-out capability, but the protocols ATOCA will define will include both opt-in and opt-out mechanisms. The group will explore how to support both opt-in and opt-out at the level of communication protocols and/or device behavior.

Another class of recipients that are in scope of the work are
explicit opt-in subscriptions which ask for alerts for a specified
location, not necessarily the physical location of the device itself.
An example of such a subscription would be ‘send me alerts for
location x’ (previously determined as the location of interest).
This work may build on existing IETF GEOPRIV location work.

There are efforts in other fora on early warning, which will be
considered in this effort.  For example, we expect to make use
of the OASIS Common Alerting Protocol (CAP) for the encoding of
alerts. OGC, ATIS, TIA, ITU-T, ETSI and 3GPP also have alert
efforts underway, and consultation with these efforts will be
undertaken to avoid unnecessary duplication of effort and also
to avoid unintentional negative impacts on the networks. Of course, existing protocols for delivering messages (e.g., SIP) will be the basis for the message delivery system of this working group.

The security implications of mechanisms that can send alerts to
billions of devices are profound, but the utility of the mechanism
encourages us to face the problems and solve them. In addition, the potential performance and congestion impacts to networks resulting from sending alert information to billions of devices must be considered and solved if such a service is implementable. To avoid manual configuration of servers distributing alerts a discovery mechanism will be specified.

Goals and Milestones

Aug 2010  Submit “Terminology and Framework” document as initial WG item. A starting point for this work is

Sep 2010  Submit “Conveying alerts in SIP” document as initial
WG item.
A starting point for this work is draft-rosen-sipping-cap.

Dec 2010  Submit “Conveying alerts through point-to-multipoint
methods” document as initial WG item.

Oct 2010  Submit “Discovering alerting servers” document as initial WG item. A starting point for this work is

Dec 2010  Submit “Addressing security, performance and
congestion issues for alert distribution” document as
initial WG item.

Jan 2011  Submit “Interfacing existing alert distribution systems”
document as initial WG item.

Jan 2011  Submit “Terminology and Framework” to the IESG for
consideration as an Informational RFC.

Mar 2011  Submit “Conveying alerts in SIP” to the IESG for
consideration as a Standards Track RFC.

May 2011  Submit “Conveying alerts through point-to-multipoint
methods” to the IESG for consideration as an
Informational RFC.

Apr 2011  Submit “Discovering alerting servers” to the IESG for
consideration as a Standards Track RFC.

Jun 2011  Submit “Addressing security, performance and
congestion issues for alert distribution” to the IESG for consideration as an Informational RFC.

Aug 2011  Submit “Interfacing existing alert distribution systems”
to the IESG for consideration as an Informational RFC.

More information can be found on the ATOCA mailing list at

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