<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:st1="urn:schemas-microsoft-com:office:smarttags" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 11 (filtered medium)">
<!--[if !mso]>
<style>
v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style>
<![endif]--><o:SmartTagType
namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PersonName"/>
<!--[if !mso]>
<style>
st1\:*{behavior:url(#default#ieooui) }
</style>
<![endif]-->
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman";
color:black;}
a:link, span.MsoHyperlink
{color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal;
font-family:Arial;
color:windowtext;}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:Arial;
color:navy;}
@page Section1
{size:595.3pt 841.9pt;
margin:72.0pt 90.0pt 72.0pt 90.0pt;}
div.Section1
{page:Section1;}
/* List Definitions */
@list l0
{mso-list-id:464353395;
mso-list-template-ids:1667769626;}
@list l0:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:36.0pt;
mso-level-number-position:left;
text-indent:-18.0pt;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l1
{mso-list-id:1332486959;
mso-list-template-ids:440816452;}
@list l1:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:36.0pt;
mso-level-number-position:left;
text-indent:-18.0pt;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l2
{mso-list-id:1662655178;
mso-list-template-ids:-1093374626;}
@list l2:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:36.0pt;
mso-level-number-position:left;
text-indent:-18.0pt;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l3
{mso-list-id:1672558748;
mso-list-template-ids:-583512678;}
@list l3:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:36.0pt;
mso-level-number-position:left;
text-indent:-18.0pt;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l4
{mso-list-id:1731612237;
mso-list-template-ids:1613642436;}
@list l4:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:36.0pt;
mso-level-number-position:left;
text-indent:-18.0pt;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
ol
{margin-bottom:0cm;}
ul
{margin-bottom:0cm;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body bgcolor=white lang=EN-GB link=blue vlink=purple>
<div class=Section1>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Scott,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I believe this same issue also affects the
<i><span style='font-style:italic'>reconnect</span></i> MPDU. Currently reconnection
messages only contain MAMS and node number data; no delivery vector data is
available for a registrar to extract.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Darren<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<div>
<div class=MsoNormal align=center style='text-align:center'><font size=3
color=black face="Times New Roman"><span lang=EN-US style='font-size:12.0pt;
color:windowtext'>
<hr size=2 width="100%" align=center tabindex=-1>
</span></font></div>
<p class=MsoNormal><b><font size=2 color=black face=Tahoma><span lang=EN-US
style='font-size:10.0pt;font-family:Tahoma;color:windowtext;font-weight:bold'>From:</span></font></b><font
size=2 color=black face=Tahoma><span lang=EN-US style='font-size:10.0pt;
font-family:Tahoma;color:windowtext'> Scott Burleigh [mailto:<st1:PersonName
w:st="on">Scott.Burleigh@jpl.nasa.gov</st1:PersonName>] <br>
<b><span style='font-weight:bold'>Sent:</span></b> 10 June 2008 17:32<br>
<b><span style='font-weight:bold'>To:</span></b> Darren Everley<br>
<b><span style='font-weight:bold'>Cc:</span></b> sis-ams@mailman.ccsds.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: AMS Question</span></font><font
color=black><span lang=EN-US style='color:windowtext'><o:p></o:p></span></font></p>
</div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'>Darren Everley wrote: <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'>Scott,<u1:p></u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'>I am working here at Scisys with Stuart Fowell on a
prototype implementation of AMS and have encountered something I would like to
run past you.<u1:p></u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'>It is with regard to Node Registration and in
particular the <i><span style='font-style:italic'>I_am_here </span></i> mpdu
when sent by a Registrar. Hopefully my attempt at an explanation below is
clear;<u1:p></u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'>Reading through the spec. in section 4.2.5 where Node
Registration is detailed there are two possible implementation choices that can
be made; to either extract information from the mpdus which are passed through
the Registrar and then forward on these data in the appropriate situations, or
do not and allow the Nodes to take care of this themselves after being
introduced to one another.<u1:p></u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'>We are going with the first choice and extracting
information as it is passed through the Registrar, hence using the <i><span
style='font-style:italic'>node_has_started</span></i> mpdu to notify other
Nodes of a new Node starting. <u1:p></u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'>The way I read the spec. is as follows;<u1:p></u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<ul style='margin-top:0cm' type=disc>
<li class=MsoNormal style='mso-list:l4 level1 lfo1'><font size=2 color=black
face=Arial><span style='font-size:10.0pt;font-family:Arial'>New Node sends
<i><span style='font-style:italic'>node_registration</span></i> to
Registrar<u1:p></u1:p></span></font><o:p></o:p></li>
</ul>
<p class=MsoNormal style='margin-left:18.0pt'><font size=2 color=black
face=Arial><span style='font-size:10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<ul style='margin-top:0cm' type=disc>
<li class=MsoNormal style='mso-list:l2 level1 lfo2'><font size=2 color=black
face=Arial><span style='font-size:10.0pt;font-family:Arial'>Registrar
sends <i><span style='font-style:italic'>you_are_in</span></i> to new Node<u1:p></u1:p></span></font><o:p></o:p></li>
</ul>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<ul style='margin-top:0cm' type=disc>
<li class=MsoNormal style='mso-list:l0 level1 lfo3'><font size=2 color=black
face=Arial><span style='font-size:10.0pt;font-family:Arial'>Registrar
sends <i><span style='font-style:italic'>I_am_here</span></i> to new Node
containing details of all other registered Nodes (mams endpoint, delivery
vectors, invitations, subscriptions, etc)<u1:p></u1:p></span></font><o:p></o:p></li>
</ul>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<ul style='margin-top:0cm' type=disc>
<li class=MsoNormal style='mso-list:l1 level1 lfo4'><font size=2 color=black
face=Arial><span style='font-size:10.0pt;font-family:Arial'>Registrar
sends <i><span style='font-style:italic'>node_has_started</span></i> on
behalf of the new Node to every other registered Node<u1:p></u1:p></span></font><o:p></o:p></li>
</ul>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal style='margin-left:18.0pt'><font size=2 color=black
face=Arial><span style='font-size:10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<ul style='margin-top:0cm' type=disc>
<li class=MsoNormal style='mso-list:l3 level1 lfo5'><font size=2 color=black
face=Arial><span style='font-size:10.0pt;font-family:Arial'>New Node sends
<i><span style='font-style:italic'>declaration</span></i> to each Node
identified within <i><span style='font-style:italic'>I_am_here<u1:p></u1:p></span></i></span></font><o:p></o:p></li>
</ul>
<p class=MsoNormal><i><font size=2 color=black face=Arial><span
style='font-size:10.0pt;font-family:Arial;font-style:italic'><u1:p> </u1:p></span></font></i><o:p></o:p></p>
<p class=MsoNormal><i><font size=2 color=black face=Arial><span
style='font-size:10.0pt;font-family:Arial;font-style:italic'><u1:p> </u1:p></span></font></i><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'>The problem I have is this; the <i><span
style='font-style:italic'>I_am_here</span></i> mpdu contains alongside a list
of invitations and subscriptions the delivery vectors for each Node. The
way I am reading the spec. it appears the delivery vector information is never
passed to the Registrar, and therefore the Registrar cannot extract this from the
mpdus to then pass on at a later date.<u1:p></u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'>The end result of this would appear to be that when a
new Node registers the information provided to it will always contain zero
length delivery vectors, and therefore no node will be able to communicate with
another.<u1:p></u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'><u1:p> </u1:p></span></font><o:p></o:p></p>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'>If I have missed something glaringly obvious then I
would appreciate a pointer in the right direction.</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'>Excellent catch, Darren, and it's a question that I
think ought to go to the Working Group for discussion.<br>
<br>
This is a vestige of the original design, in which the registering node sent
its own <i><span style='font-style:italic'>I_am_starting</span></i> (via the
registrar), its peers always responded directly to it with their own <i><span
style='font-style:italic'>I_am_here</span></i> messages containing their
delivery vector lists, and the registering node directly returned <i><span
style='font-style:italic'>declaration</span></i>s that contained its delivery
vector list -- the Registrar never had any need to see any delivery
vectors. But because the Registrar may now be responsible for getting the
delivery vectors out to the nodes in <i><span style='font-style:italic'>I_am_here</span></i>,
it now must receive them.<br>
<br>
So I think we need to modify the spec in a couple of small ways:<br>
<br>
1. The <i><span style='font-style:italic'>node_registration</span></i>
message must now contain not only the MAMS endpoint name but also the
registering node's delivery vectors list. This assures that the registrar
has this information and can pass it on in later <i><span style='font-style:
italic'>I_am_here</span></i> messages.<br>
<br>
2. But since the registrar now has this information and is the
source of all <i><span style='font-style:italic'>I_am_starting</span></i>/<i><span
style='font-style:italic'>node_has_started</span></i> messages, why make the
registering node send its delivery vectors list again in subsequent declaration
messages? (And why make the new node's peers wait for declarations before
getting that information?) It's simpler and a little more efficient to
add delivery vectors list to <i><span style='font-style:italic'>I_am_starting</span></i>
and <i><span style='font-style:italic'>node_has_started</span></i>, and remove
it from the declaration structure.<br>
<br>
Anybody see anything wrong with this revision? If not, I'll post a
tweaked Red 2 in a couple of days.<br>
<br>
Scott<o:p></o:p></span></font></p>
</div>
</body>
</html>