[docs] Update protocol docsv0.2.0

1 files changed, 129 insertions, 35 deletions

diff --git a/docs/rfc.html b/docs/rfc.html
index 84b5c0a..99a6a34 100644
--- a/docs/rfc.html
+++ b/docs/rfc.html
@@ -1220,7 +1220,7 @@ li > p:last-of-type:only-child {
 </tr></thead>
 <tfoot><tr>
 <td class="left">bt</td>
-<td class="center">Expires 16 October 2026</td>
+<td class="center">Expires 20 October 2026</td>
 <td class="right">[Page]</td>
 </tr></tfoot>
 </table>
@@ -1233,12 +1233,12 @@ li > p:last-of-type:only-child {
 <dd class="internet-draft">SOLEC</dd>
 <dt class="label-published">Published:</dt>
 <dd class="published">
-<time datetime="2026-04-14" class="published">14 April 2026</time>
+<time datetime="2026-04-18" class="published">18 April 2026</time>
     </dd>
 <dt class="label-intended-status">Intended Status:</dt>
 <dd class="intended-status">Experimental</dd>
 <dt class="label-expires">Expires:</dt>
-<dd class="expires"><time datetime="2026-10-16">16 October 2026</time></dd>
+<dd class="expires"><time datetime="2026-10-20">20 October 2026</time></dd>
 <dt class="label-authors">Author:</dt>
 <dd class="authors">
 <div class="author">
@@ -1274,7 +1274,7 @@ SOLEC system.<a href="#section-abstract-1" class="pilcrow">¶</a></p>
         time. It is inappropriate to use Internet-Drafts as reference
         material or to cite them other than as "work in progress."<a href="#section-boilerplate.1-3" class="pilcrow">¶</a></p>
 <p id="section-boilerplate.1-4">
-        This Internet-Draft will expire on 16 October 2026.<a href="#section-boilerplate.1-4" class="pilcrow">¶</a></p>
+        This Internet-Draft will expire on 20 October 2026.<a href="#section-boilerplate.1-4" class="pilcrow">¶</a></p>
 </section>
 </div>
 <div id="copyright">
@@ -1350,21 +1350,33 @@ SOLEC system.<a href="#section-abstract-1" class="pilcrow">¶</a></p>
                     <p id="section-toc.1-1.2.2.4.2.3.1"><a href="#section-2.4.3" class="auto internal xref">2.4.3</a>.  <a href="#name-handshake" class="internal xref">Handshake</a></p>
 </li>
                   <li class="compact toc ulBare ulEmpty" id="section-toc.1-1.2.2.4.2.4">
-                    <p id="section-toc.1-1.2.2.4.2.4.1"><a href="#section-2.4.4" class="auto internal xref">2.4.4</a>.  <a href="#name-auth" class="internal xref">Auth</a></p>
+                    <p id="section-toc.1-1.2.2.4.2.4.1"><a href="#section-2.4.4" class="auto internal xref">2.4.4</a>.  <a href="#name-userauth" class="internal xref">UserAuth</a></p>
 </li>
                   <li class="compact toc ulBare ulEmpty" id="section-toc.1-1.2.2.4.2.5">
-                    <p id="section-toc.1-1.2.2.4.2.5.1"><a href="#section-2.4.5" class="auto internal xref">2.4.5</a>.  <a href="#name-message" class="internal xref">Message</a></p>
+                    <p id="section-toc.1-1.2.2.4.2.5.1"><a href="#section-2.4.5" class="auto internal xref">2.4.5</a>.  <a href="#name-serverauth" class="internal xref">ServerAuth</a></p>
 </li>
                   <li class="compact toc ulBare ulEmpty" id="section-toc.1-1.2.2.4.2.6">
-                    <p id="section-toc.1-1.2.2.4.2.6.1"><a href="#section-2.4.6" class="auto internal xref">2.4.6</a>.  <a href="#name-test" class="internal xref">Test</a></p>
+                    <p id="section-toc.1-1.2.2.4.2.6.1"><a href="#section-2.4.6" class="auto internal xref">2.4.6</a>.  <a href="#name-message" class="internal xref">Message</a></p>
+</li>
+                  <li class="compact toc ulBare ulEmpty" id="section-toc.1-1.2.2.4.2.7">
+                    <p id="section-toc.1-1.2.2.4.2.7.1"><a href="#section-2.4.7" class="auto internal xref">2.4.7</a>.  <a href="#name-test" class="internal xref">Test</a></p>
 </li>
                 </ul>
 </li>
               <li class="compact toc ulBare ulEmpty" id="section-toc.1-1.2.2.5">
                 <p id="section-toc.1-1.2.2.5.1"><a href="#section-2.5" class="auto internal xref">2.5</a>.  <a href="#name-sequential-operations" class="internal xref">Sequential operations</a></p>
+</li>
+              <li class="compact toc ulBare ulEmpty" id="section-toc.1-1.2.2.6">
+                <p id="section-toc.1-1.2.2.6.1"><a href="#section-2.6" class="auto internal xref">2.6</a>.  <a href="#name-client-server-connection-in" class="internal xref">Client-Server connection initialisation</a></p>
+</li>
+              <li class="compact toc ulBare ulEmpty" id="section-toc.1-1.2.2.7">
+                <p id="section-toc.1-1.2.2.7.1"><a href="#section-2.7" class="auto internal xref">2.7</a>.  <a href="#name-exchanging-messages-between" class="internal xref">Exchanging messages between servers</a></p>
 <ul class="compact toc ulBare ulEmpty">
-<li class="compact toc ulBare ulEmpty" id="section-toc.1-1.2.2.5.2.1">
-                    <p id="section-toc.1-1.2.2.5.2.1.1"><a href="#section-2.5.1" class="auto internal xref">2.5.1</a>.  <a href="#name-connection-initialisation" class="internal xref">Connection initialisation</a></p>
+<li class="compact toc ulBare ulEmpty" id="section-toc.1-1.2.2.7.2.1">
+                    <p id="section-toc.1-1.2.2.7.2.1.1"><a href="#section-2.7.1" class="auto internal xref">2.7.1</a>.  <a href="#name-authentication" class="internal xref">Authentication</a></p>
+</li>
+                  <li class="compact toc ulBare ulEmpty" id="section-toc.1-1.2.2.7.2.2">
+                    <p id="section-toc.1-1.2.2.7.2.2.1"><a href="#section-2.7.2" class="auto internal xref">2.7.2</a>.  <a href="#name-server-server-connection-in" class="internal xref">Server-Server connection initialisation</a></p>
 </li>
                 </ul>
 </li>
@@ -1582,7 +1594,7 @@ Text is encoded using UTF-8.<a href="#section-2.3.3-1" class="pilcrow">¶</a></p
             </tr>
             <tr>
               <td class="text-left" rowspan="1" colspan="1">0x04</td>
-              <td class="text-left" rowspan="1" colspan="1">Auth</td>
+              <td class="text-left" rowspan="1" colspan="1">UserAuth</td>
               <td class="text-left" rowspan="1" colspan="1">C</td>
             </tr>
             <tr>
@@ -1591,6 +1603,11 @@ Text is encoded using UTF-8.<a href="#section-2.3.3-1" class="pilcrow">¶</a></p
               <td class="text-left" rowspan="1" colspan="1">SC</td>
             </tr>
             <tr>
+              <td class="text-left" rowspan="1" colspan="1">0x06</td>
+              <td class="text-left" rowspan="1" colspan="1">ServerAuth</td>
+              <td class="text-left" rowspan="1" colspan="1">S</td>
+            </tr>
+            <tr>
               <td class="text-left" rowspan="1" colspan="1">0xFF</td>
               <td class="text-left" rowspan="1" colspan="1">Test</td>
               <td class="text-left" rowspan="1" colspan="1">R</td>
@@ -1641,7 +1658,7 @@ Text is encoded using UTF-8.<a href="#section-2.3.3-1" class="pilcrow">¶</a></p
               <tbody>
                 <tr>
                   <td class="text-left" rowspan="1" colspan="1">0x01</td>
-                  <td class="text-left" rowspan="1" colspan="1">Auth failed. Invalid username or password.</td>
+                  <td class="text-left" rowspan="1" colspan="1">Client auth failed. Invalid username or password.</td>
                 </tr>
                 <tr>
                   <td class="text-left" rowspan="1" colspan="1">0x02</td>
@@ -1713,10 +1730,10 @@ different auth method will be used.<a href="#section-2.4.3.1-1" class="pilcrow">
 </div>
 </section>
 </div>
-<div id="auth">
+<div id="userauth">
 <section id="section-2.4.4">
-          <h4 id="name-auth">
-<a href="#section-2.4.4" class="section-number selfRef">2.4.4. </a><a href="#name-auth" class="section-name selfRef">Auth</a>
+          <h4 id="name-userauth">
+<a href="#section-2.4.4" class="section-number selfRef">2.4.4. </a><a href="#name-userauth" class="section-name selfRef">UserAuth</a>
           </h4>
 <table class="center" id="table-6">
             <caption><a href="#table-6" class="selfRef">Table 6</a></caption>
@@ -1739,10 +1756,10 @@ different auth method will be used.<a href="#section-2.4.3.1-1" class="pilcrow">
           </table>
 </section>
 </div>
-<div id="message">
+<div id="serverauth">
 <section id="section-2.4.5">
-          <h4 id="name-message">
-<a href="#section-2.4.5" class="section-number selfRef">2.4.5. </a><a href="#name-message" class="section-name selfRef">Message</a>
+          <h4 id="name-serverauth">
+<a href="#section-2.4.5" class="section-number selfRef">2.4.5. </a><a href="#name-serverauth" class="section-name selfRef">ServerAuth</a>
           </h4>
 <table class="center" id="table-7">
             <caption><a href="#table-7" class="selfRef">Table 7</a></caption>
@@ -1755,6 +1772,28 @@ different auth method will be used.<a href="#section-2.4.3.1-1" class="pilcrow">
             <tbody>
               <tr>
                 <td class="text-left" rowspan="1" colspan="1">string</td>
+                <td class="text-left" rowspan="1" colspan="1">name</td>
+              </tr>
+            </tbody>
+          </table>
+</section>
+</div>
+<div id="message">
+<section id="section-2.4.6">
+          <h4 id="name-message">
+<a href="#section-2.4.6" class="section-number selfRef">2.4.6. </a><a href="#name-message" class="section-name selfRef">Message</a>
+          </h4>
+<table class="center" id="table-8">
+            <caption><a href="#table-8" class="selfRef">Table 8</a></caption>
+<thead>
+              <tr>
+                <th class="text-left" rowspan="1" colspan="1">Type</th>
+                <th class="text-left" rowspan="1" colspan="1">Name</th>
+              </tr>
+            </thead>
+            <tbody>
+              <tr>
+                <td class="text-left" rowspan="1" colspan="1">string</td>
                 <td class="text-left" rowspan="1" colspan="1">source_address</td>
               </tr>
               <tr>
@@ -1774,14 +1813,14 @@ different auth method will be used.<a href="#section-2.4.3.1-1" class="pilcrow">
 </section>
 </div>
 <div id="test">
-<section id="section-2.4.6">
+<section id="section-2.4.7">
           <h4 id="name-test">
-<a href="#section-2.4.6" class="section-number selfRef">2.4.6. </a><a href="#name-test" class="section-name selfRef">Test</a>
+<a href="#section-2.4.7" class="section-number selfRef">2.4.7. </a><a href="#name-test" class="section-name selfRef">Test</a>
           </h4>
-<p id="section-2.4.6-1">Test payload is used for encoder and decoders testing. Clients and servers
-should ignore this kind of payload.<a href="#section-2.4.6-1" class="pilcrow">¶</a></p>
-<table class="center" id="table-8">
-            <caption><a href="#table-8" class="selfRef">Table 8</a></caption>
+<p id="section-2.4.7-1">Test payload is used for encoder and decoders testing. Clients and servers
+should ignore this kind of payload.<a href="#section-2.4.7-1" class="pilcrow">¶</a></p>
+<table class="center" id="table-9">
+            <caption><a href="#table-9" class="selfRef">Table 9</a></caption>
 <thead>
               <tr>
                 <th class="text-left" rowspan="1" colspan="1">Type</th>
@@ -1835,12 +1874,14 @@ should ignore this kind of payload.<a href="#section-2.4.6-1" class="pilcrow">¶
 <p id="section-2.5-1">Some operations require multiple rounds of communication.
 In this case payloads are send in a sequence. Payload that is not part of this
 specific operation (for example incoming message) cannot interrupt this process.<a href="#section-2.5-1" class="pilcrow">¶</a></p>
-<div id="connection-initialisation">
-<section id="section-2.5.1">
-          <h4 id="name-connection-initialisation">
-<a href="#section-2.5.1" class="section-number selfRef">2.5.1. </a><a href="#name-connection-initialisation" class="section-name selfRef">Connection initialisation</a>
-          </h4>
-<div class="lang-ascii-art sourcecode" id="section-2.5.1-1">
+</section>
+</div>
+<div id="client-server-connection-initialisation">
+<section id="section-2.6">
+        <h3 id="name-client-server-connection-in">
+<a href="#section-2.6" class="section-number selfRef">2.6. </a><a href="#name-client-server-connection-in" class="section-name selfRef">Client-Server connection initialisation</a>
+        </h3>
+<div class="lang-ascii-art sourcecode" id="section-2.6-1">
 <pre>+--------+                   +--------+
 | Client |                   | Server |
 +----+---+                   +----+---+
@@ -1851,19 +1892,72 @@ specific operation (for example incoming message) cannot interrupt this process.
      | Send [Handshake]           |
      +---------------------------&gt;|
      |                            |
-     |                            +- If [ver_major] does not match server
-     |                            |  protocol version close the connection
+     |                            +- If [ver_major] does not match
+     |                            |  server protocol version close
+     |                            |  the connection.
      |                            |
-     | Send [Auth]                |
+     | Send [UserAuth]            |
      +---------------------------&gt;|
      |                            |
      | Send [Error 0x01]          |
-     |&lt;---------------------------+- If [username] or [password] does not match
-     |                            |  and close the connection
+     |&lt;---------------------------+- If [username] or [password]
+     |                            |  does not match and close
+     |                            |  the connection.
+     |                            |
+     | Send [Sucesss]             |
+     |&lt;---------------------------+
+</pre><a href="#section-2.6-1" class="pilcrow">¶</a>
+</div>
+</section>
+</div>
+<div id="exchanging-messages-between-servers">
+<section id="section-2.7">
+        <h3 id="name-exchanging-messages-between">
+<a href="#section-2.7" class="section-number selfRef">2.7. </a><a href="#name-exchanging-messages-between" class="section-name selfRef">Exchanging messages between servers</a>
+        </h3>
+<p id="section-2.7-1">Exchanging messages between SOLEC servers is a core concept behind the project.
+Sending message to user residing on a different server require estabilishing a
+connection between both servers.<a href="#section-2.7-1" class="pilcrow">¶</a></p>
+<div id="authentication">
+<section id="section-2.7.1">
+          <h4 id="name-authentication">
+<a href="#section-2.7.1" class="section-number selfRef">2.7.1. </a><a href="#name-authentication" class="section-name selfRef">Authentication</a>
+          </h4>
+<p id="section-2.7.1-1">Server authentication is crucial to prevent message spoofing and other forms of
+abuse. Server cannot use same auth process as clients because that would require
+creating account for each server on any other server which is impossible.
+Possible solution are TLS or other public key based protocol.<a href="#section-2.7.1-1" class="pilcrow">¶</a></p>
+<p id="section-2.7.1-2">As for now the issue remains open and server authorization uses mock
+[ServerAuth] payload which specifies just the connecting server name.
+This is obviously insecure.<a href="#section-2.7.1-2" class="pilcrow">¶</a></p>
+</section>
+</div>
+<div id="server-server-connection-initialisation">
+<section id="section-2.7.2">
+          <h4 id="name-server-server-connection-in">
+<a href="#section-2.7.2" class="section-number selfRef">2.7.2. </a><a href="#name-server-server-connection-in" class="section-name selfRef">Server-Server connection initialisation</a>
+          </h4>
+<div class="lang-ascii-art sourcecode" id="section-2.7.2-1">
+<pre>+--------+                   +--------+
+| Server |                   | Server |
++----+---+                   +----+---+
+     |                            |
+     | Initialise TCP connection  |
+     +---------------------------&gt;|
+     |                            |
+     | Send [Handshake]           |
+     +---------------------------&gt;|
+     |                            |
+     |                            +- If [ver_major] does not match
+     |                            |  server protocol version close
+     |                            |  the connection.
+     |                            |
+     | Send [ServerAuth]          |
+     +---------------------------&gt;|
      |                            |
      | Send [Sucesss]             |
      |&lt;---------------------------+
-</pre><a href="#section-2.5.1-1" class="pilcrow">¶</a>
+</pre><a href="#section-2.7.2-1" class="pilcrow">¶</a>
 </div>
 </section>
 </div>