GCN/DOW_TOD Test Notices

TABLE OF CONTENTS:

1. Introduction
2. Purpose/Motvation
3. Specification Format
4. Accuracy of the Create Time
5. Distribution Methods
6. Notice Example
7. Comment for Socket Sites
8. Formats
9. Filtering
10. Error Boxes
11. Test Notices
12. Further Help
13. E-mail Example
14. Cell/Pager Example
15. Short-form Cell/Pager Example
16. Subject-only Cell/Pager Examples

INTRODUCTION

This notice type allows users to monitor the connectivity and delivery time of Notices
from GCN to themselves. The notice type is called DOW_TOD (Day of Week Time of Day).
It will be sent at the time you request on the days you request.

PURPOSE/MOTIVATION:

There are two motivations (uses) for this notice type:
1) It allows email-based customers to do a spot-check
on their connectivity (this is particularly useful
for cellphone-based customers). (Socket-based customers
already have this connectivity capability via the Imalive packets.)
2) It allows the recipient to periodically determine the time delay
of the total delivery system. GCN does this by creating and sending
a special notice at the time-of-day you request (the notice
has the creation date/time_stamp in the notice). Then you can look
at the receive time to see how many seconds have ellapsed.
(For email-based customers, the top-most "Received:" line
in the email full-header has the timestamp at the final destination
computer (your computer).) (The GCN computer is slaved
to a Network Time Server machine and is never more than 200 msec off of UT;
typically not more than 60 msec. Is your computer slaved
to a time-server? Also be aware that mail-agents only check/fetch
for "new mail" on a periodic basis (eg every 60 sec), so that will
cause additional (sometimes long) delivery delays.)

Here is a histogram of the Delivery_Time delays (the time between the time the notice was created
and the time when the notice actually arrived at a test machine in the U. of Chicago):

SPECIFICATION FORMAT:

The specification to enable this notice type is a little different
than the specifications for the regular GRB/Transient notice types.
For DOW_TOD Test notices, the entry in your configuration will look like:
DOW_TOD_TEST 0x7F,12:00
This particular entry would result in a DOW_TOD notice
being sent every day (Sun through Sat) at 12:00:00 UT.
The first part (0x7F) is a bit mask to select the day(s) of the week
you want to receive the notice ((Sun is 2^0 and Sat is 2^6).
The second part (12:00) is the hour and minute of the day you want to receive.
If you just wanted to receive them only on Tuesdays at 20:35:00 UT,
the entry would be:                     DOW_TOD_TEST 0x04,20:35
Weekdays at 16:00 would be:     DOW_TOD_TEST 0x3E,16:00
Fridays at 16:00 would be:         DOW_TOD_TEST 0x20,16:00

ACCURACY OF THE CREATE TIME:

The specific notice for each customer is created within 2 sec
of the time requested (eg 20:35 would have the notice created
between 20:35:00.0 and 20:35:01.99 UT)
Of course, this is dependant on the load on the GCN computer.
Based on trial runs of 114 notices over 5 days of testing,
the distribution of deviations from the specified creation times
ranged from 1 to 5 sec (mean of 1.2 sec).
Of course, because the actual creation timestamp is in each notice,
you will always be able to determine the delivery delay.

Here is a histogram of the Request_Time delays (the time between the time specified
in the DOW_TOD_TEST configuration entry and the time when the notice was actually created):

DISTRIBUTION METHODS:

This notice is available via all the distribution methods within GCN:
full-format email, all 4 cell/pager formats, XML email, and
socket (160-byte binary and VOEvent XML).
GCN will use the distribution method/format for which your site is
already configured.

NOTICE EXAMPLE:

Here is an example of a full-format email DOW_TOD Notice:

    TITLE:        GCN/DOW_TOD Check Notice
    NOTICE_DATE:  Mon 30 May 11 22:35:01 UT

COMMENT FOR SOCKET SITES:

Socket sites are already accustomed to being able to monitor
their delivery delays via the Daily_Socket_Connection Reports
which contain a histogram of the round-trip delivery times
for all the packets they are sent and that they echo back to GCN.
So this DOW_TOD notice is designed primarily for the email-based
customers, but any site can sign up for it.

FORMATS:

Samples of the E-mail, Cell/Pager, Short-form Cell/Pager, and the 2 Subject-only
distribution methods of the GCN/DOW_TOD Notice type are included below.
(It is also available in XML format via email and sockets.)

The socket packet contents and format are similar to the other mission-specific packet types
and are described in detail in the socket packet definition document.
The DOW_TOD Test Notice is Type=48.

Filtering:
Unlike all the other GCN Notice types, the site's filtering criteria
do not apply to the DOW_TOD Test notice type. By it's very nature,
the "filtering" has already been specified.

Error Boxes:
There is no location error associated with the DOW_TOD Test Noitices
(unlike all the other GCN Notice types).

Test Notices:
There is no "test" version of the DOW_TOD Test Notices
(unlike nearly all the other GCN Notice types).

Further Help:
For further information on this, please contact Scott Barthelmy.

An example of the DOW_TOD Test Notice type of the e-mail formats is shown below.
The "/////" divider bars are NOT part of the messages.

For those sites/people that use demons and/or incoming e-mail filters,
the "Subject" lines for the all notice types: GCN/DOW_TOD

///////////////////////// Full-format E-mail format ////////////////////
TITLE:        GCN/DOW_TOD Check Notice
NOTICE_DATE:  Mon 30 May 11 22:35:01 UT
////////////////////////////////////////////////////////////////////////

An example of the (regular) cell/pager format is shown below.
There are no "Subject" lines for these e-mails sent to the cell/pager companies
because the Subject line would use up valuable character counts
from the maximum displayable for the body of the message.

///////////////////////// Cell/Pager format ///////////////////////////
TITLE:        GCN/DOW_TOD Check Notice
NOTICE_DATE:  Mon 30 May 11 22:35:01 UT
///////////////////////////////////////////////////////////////////////

An example of the short-form cell/pager format is shown below.
There are no "Subject" lines for these e-mails sent to the cell/pager companies,
because the Subject-line would use up valuable character counts from the maximum
displayable for the body of the message. And it was the very limited
display character count of some companies that motivated the short-form pager
method in the first place.

///////////////////////// Short-Cell/Pager format ///////////////////////
TITLE:        GCN/DOW_TOD Check Notice
NOTICE_DATE:  Mon 30 May 11 22:35:01 UT
/////////////////////////////////////////////////////////////////////////

Normally there are two variations of the Subject-only format: decimal degrees (Current epoch)
and RA=hh:mm:ss Dec=DDdMMmSSs format (J2000 epoch). Because there is no RA,Dec location
associated with this DOW_TOD notice type, the two variations identical:

///////////////////////// Subject-only formats ///////////////////////////
DOW_TOD 22:35:01 UT
//////////////////////////////////////////////////////////////////////////
DOW_TOD 22:35:01 UT
//////////////////////////////////////////////////////////////////////////