- Proposed new I2CP options for 0.9.2

- I2NP Garlic clove/message clarifications

www.i2p2/pages/i2cp.html

@@ -79,6 +79,7 @@ The following options are traditionally passed to the router via
 a <a href="i2cp_spec.html#type_SessionConfig">SessionConfig</a> contained in a <a href="i2cp_spec.html#msg_CreateSession">CreateSession Message</a> or a <a href="i2cp_spec.html#msg_ReconfigureSession">ReconfigureSession Message</a>.
 <p>
 <table border=1>
+<tr><th colspan="5">Router-side Options</th></tr>
 <tr><th>Option <th>Recommended Arguments <th>Allowable Range<th>Default<th>Description
 <tr><td>inbound.quantity <td>number from 1 to 3 <td>1 to 16<td>2<td>Number of tunnels in.
      Limit was increased from 6 to 16 in release 0.9; however, numbers higher than 6 are not
@@ -116,6 +117,32 @@ a <a href="i2cp_spec.html#type_SessionConfig">SessionConfig</a> contained in a <
         If the client is running in the same JVM as a router, this option is not required.
 <tr><td>i2cp.password<td>string<td>&nbsp;<td>&nbsp;<td>For authorization, if required by the router (since 0.8.2).
         If the client is running in the same JVM as a router, this option is not required.
+<tr><td>crypto.tagsToSend<td>&nbsp;<td>1-128<td>40<td>Number of ElGamal/AES Session Tags to send at a time (since 0.9.2).
+        For clients with relatively low bandwidth per-client-pair (IRC, some UDP apps), this may be set lower.
+<tr><td>crypto.lowTagThreshold<td>&nbsp;<td>1-128<td>30<td>Minimum number of ElGamal/AES Session Tags before we send more (since 0.9.2).
+        Recommended: approximately tagsToSend * 2/3
+<tr><td>shouldBundleReplyInfo<td>true, false<td>&nbsp;<td>true<td>Set to false to disable ever bundling a reply LeaseSet (since 0.9.2).
+      For clients that do not publish their LeaseSet, this option must be true
+      for any reply to be possible. "true" is also recommended for multihomed servers
+      with long connection times.
+     
+  <p> Setting to "false" may save significant outbound bandwidth, especially if
+      the client is configured with a large number of inbound tunnels (Leases).
+      If replies are still required, this may shift the bandwidth burden to
+      the far-end client and the floodfill.
+      There are several cases where "false" is may be appropriate:
+     <ul><li>
+      Unidirectional communication, no reply required
+      <li>
+      LeaseSet is published and higher reply latency is acceptable
+      <li>
+     LeaseSet is published, client is a "server", all connections are inbound
+      so the connecting far-end destination obviously has the leaseset already.
+      Connections are either short, or it is acceptable for latency on a long-lived
+      connection to temporarily increase while the other end re-fetches the LeaseSet
+      after expiration.
+      HTTP servers may fit these requirements.
+      </li></ul>
 <tr><td>inbound.*<td>&nbsp;<td>&nbsp;<td>&nbsp;<td>Any other options prefixed with "inbound." are stored
         in the "unknown options" properties of the inbound tunnel pool's settings.
 <tr><td>outbound.*<td>&nbsp;<td>&nbsp;<td>&nbsp;<td>Any other options prefixed with "outbound." are stored
@@ -134,6 +161,7 @@ and will be interpreted if passed to the I2PSession via the I2PClient.createSess
 The streaming lib should also pass these options through to I2CP.
 <p>
 <table border=1>
+<tr><th colspan="6">Client-side Options</th></tr>
 <tr><th>Option <th>As Of Release<th>Recommended Arguments <th>Allowable Range<th>Default<th>Description
 <tr><td>i2cp.tcp.host <td>&nbsp;<td>&nbsp;<td>&nbsp;<td>127.0.0.1<td>Router hostname.
         If the client is running in the same JVM as a router, this option is ignored, and the client connects to that router internally.

www.i2p2/pages/i2np_spec.html

@@ -2,7 +2,7 @@
 {% block title %}I2NP Specification{% endblock %}
 {% block content %}
 
-Updated January 2012, current as of router version 0.8.12
+Updated June 2012, current as of router version 0.9
 
 <h1>I2P Network Protocol (I2NP) Specification</h1>
 <p>
@@ -366,10 +366,17 @@ Certificate :: Always NULL in the current implementation (3 bytes total, all zer
   See also the <a href="how_garlicrouting.html">garlic routing specification</a>.
 <li>
   See also <a href="tunnel_message_spec.html#delivery">Delivery Instructions definition</a>
+<li>
+  Maximum length is a function of the total length of all the cloves and the
+  maximum length of the GarlicMessage.
 <li>
   In the future, the certificate could possibly be used for a HashCash to "pay" for the routing.
 <li>
-  The message is always a DataMessage?
+  The message can be any I2NP message (including a GarlicMessage, although that is not used in practice).
+  The messages used in practice are DataMessage, DeliveryStatusMessage, and DatabaseStoreMessage.
+<li>
+  The Clove ID is generally set to a random number on transmit and is checked for
+  duplicates on receive (same message ID space as top-level Message IDs)
 </ul>
 
 
@@ -785,12 +792,24 @@ Expiration :: Date (8 bytes)
 <ul>
 <li>
   When unencrypted, data contains one or more <a href="#struct_GarlicClove">Garlic Cloves</a>.
+<li>
+  The AES encrypted block is padded to a minimum of 128 bytes; with the 32-byte Session Tag
+  the minimum size of the encrypted message is 160 bytes; with the 4 length bytes
+  the minimum size of the Garlic Message is 164 bytes.
 <li>
   Actual max length is less than 64 KB; see the <a href="i2np.html">I2NP Overview</a>.
 <li>
   See also the <a href="how_elgamalaes.html">ElGamal/AES specification</a>.
 <li>
   See also the <a href="how_garlicrouting.html">garlic routing specification</a>.
+<li>
+  The 128 byte minimum size of the AES encrypted block is not currently configurable,
+  however the minimum size of a DataMessage in a GarlicClove in a GarlicMessage, with
+  overhead, is 128 bytes anyway. A configurable option to increase the minimum size
+  may be added in the future.
+<li>
+  The message ID is generally set to a random number on transmit and
+  appears to be ignored on receive.
 <li>
   In the future, the certificate could possibly be used for a HashCash to "pay" for the routing.
 </ul>