CAP-AP Question 1 - Clarification of CAP <info> block issue

[gregory.trott@ag.gov.au]

As highlighted in the EM-TC Meeting Notes from March 29, 2011 (Item 4), this question is one of two questions originally identified in the Australian "Request For Assistance - CAP-AP Development" document that I posted on the EM-TC website on 2011-03-18. 

I wish to seek EM-TC member responses to the following question, in order to obtain feedback from individual members that may possess experience with CAP issues that they are willing to share with the Australian CAP-AP project.


Question 1:  What are the advantages and disadvantages with allowing a CAP message to include:

a) multiple <eventCode> elements within a single <info> block; and

b) multiple <info> blocks that only allow one <eventCode> per block.

Preferred deadline to receive responses to this question is no later than 6th May 2011.


Background information:
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1) This information is being requested in order to resolve the follwoing issue being expressed by an Australian CAP Stakeholder: 

With multiple <info> blocks the single CAP message could contain <info> blocks assigned to areas under varying levels of threat.  The alternative approaches are: 
 the overkill of sending an alert message across a broader geographic area just to ensure it covers the threat area, or 
 sending multiple CAP messages for one event.  


Current partial explanation already appearing in the CAP-AP document:
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1) The CAP-AP document posted by me on the EM-TC website (titled CAP-AP Discussion Paper (1 of 3)) already addresses part of the answer to this issue in the following sections:
 
(Para 1.) A single CAP <alert> will be created at message origination with multiple <info> blocks  one <info> block for each disparate exchange partner, as necessary.

(Para 1.2)  the resulting CAP v1.2 structure as a single CAP v1.2 <alert> block that contains multiple <info> blocks  one per exchange partner. The intent of CAP-AP is to tailor one <info> block specifically for each particular exchange partner as necessary within criteria required for a profile.

2) I have also seen the following explanation included in the CAP-CP:  

The OASIS CAP standard allows for the use of multiple <info> segments per <alert>, but only provides for a single message identifier per <alert>. Further, OASIS CAP allows for updates and cancellations of <alerts>. The challenge is what is to be concluded when faced with an update or cancellation of only one of a multiple of <info> segments, if each <info> segment were to refer to a different event.  To avoid any potential confusion, the Canadian Profile limits each CAP <alert> to a single <info> segment except for the purpose of replicating alerts in additional languages. The only difference between multiple <info> segments is to be the value in <language>, and the language used in the descriptive fields. They will pertain to the same event type.



Thank you in advance for any comments you are willing to contribute in repsonse to this question.

Regards,

Greg Trott
CAP-AP Project Manager