From a3009ed0ed733b9e558f8cb4bd79dda49a37b991 Mon Sep 17 00:00:00 2001
From: zzz <zzz@i2pmail.org>
Date: Mon, 8 Aug 2022 14:01:08 -0400
Subject: [PATCH] Prop. 159 congestion control updates
---
i2p2www/spec/proposals/159-ssu2.rst | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/i2p2www/spec/proposals/159-ssu2.rst b/i2p2www/spec/proposals/159-ssu2.rst
index 96a634e60..1691d409e 100644
--- a/i2p2www/spec/proposals/159-ssu2.rst
+++ b/i2p2www/spec/proposals/159-ssu2.rst
@@ -6671,6 +6671,30 @@ transmitter to implement an efficient and responsive congestion control algorith
while allowing flexibility and innovation in that implementation.
This section discusses implementation goals and provides suggestions.
General guidance may be found in [RFC-9002]_.
+See also [RFC-6298]_ for guidance on retransmission timers.
+
+ACK-only data packets should not count for bytes or packets in-flight
+and are not congestion-controlled.
+Unlike in TCP, SSU2 can detect the loss of these packets and
+that information may be used to adjust the congestion state.
+However, this document does not specify a mechanism for doing so.
+
+Packets containing some other non-data blocks may also be excluded from congestion control
+if desired, implementation-dependent. For example:
+
+- Peer Test
+- Relay request/intro/response
+- Path challenge/response
+
+It is recommended that the congestion control be based on byte count, not
+packet count, following the guidance in TCP RFCs and QUIC [RFC-9002]_.
+An additional packet count limit may be useful as well to prevent
+buffer overflow in the kernel or in middleboxes, implementation dependent,
+although this may add significant complexity.
+If per-session and/or total packet output is bandwidth-limited and/or paced,
+this may mitigate the need for packet count ilmiting.
+
+
Packet Numbers
@@ -8382,6 +8406,9 @@ References
.. [RFC-6151]
https://tools.ietf.org/html/rfc6151
+.. [RFC-6298]
+ https://tools.ietf.org/html/rfc6298
+
.. [RFC-6437]
https://tools.ietf.org/html/rfc6437
--
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