From fa929b10ae867a2551ac472c1da31e46e9721bf5 Mon Sep 17 00:00:00 2001
From: Toby <tobyxdd@gmail.com>
Date: Fri, 30 Apr 2021 22:23:37 -0700
Subject: [PATCH] Optimization tips for routers and other embedded devices

---
 README.md    | 12 +++++++++++-
 README.zh.md | 11 ++++++++++-
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index f9edc25..c10f240 100644
--- a/README.md
+++ b/README.md
@@ -286,7 +286,9 @@ References:
 - https://www.kernel.org/doc/Documentation/networking/tproxy.txt
 - https://powerdns.org/tproxydoc/tproxy.md.html
 
-## Optimizing for extreme transfer speeds
+## Optimization tips
+
+### Optimizing for extreme transfer speeds
 
 If you want to use Hysteria for very high speed transfers (e.g. 10GE, 1G+ over inter-country long fat pipes), consider
 increasing your system's UDP receive buffer size.
@@ -301,6 +303,14 @@ You may also need to increase `recv_window_conn` and `recv_window` (`recv_window
 they are at least no less than the bandwidth-delay product. For example, if you want to achieve a transfer speed of 500
 MB/s on a line with an RTT of 200 ms, you need a minimum receive window size of 100 MB (500*0.2).
 
+### Routers and other embedded devices
+
+For devices with very limited computing power and RAM, turning off obfuscation can bring a slight performance boost.
+
+The default receive window size for both Hysteria server and client is 64 MB. Consider lowering them if it's too large
+for your device. Keeping a ratio of one to four between stream receive window and connection receive window is
+recommended.
+
 ## ACL
 
 [ACL File Format](ACL.md)
diff --git a/README.zh.md b/README.zh.md
index 79a4946..eb4d369 100644
--- a/README.zh.md
+++ b/README.zh.md
@@ -273,7 +273,9 @@ TPROXY 模式 (`tproxy_tcp` 和 `tproxy_udp`) 只在 Linux 下可用。
 - https://www.kernel.org/doc/Documentation/networking/tproxy.txt
 - https://powerdns.org/tproxydoc/tproxy.md.html
 
-## 针对超高传速度进行优化
+## 优化建议
+
+### 针对超高传速度进行优化
 
 如果要用 Hysteria 进行极高速度的传输 (如内网超过 10G 或高延迟跨国超过 1G)，请增加系统的 UDP receive buffer 大小。
 
@@ -286,6 +288,13 @@ sysctl -w net.core.rmem_max=4000000
 你可能还需要提高 `recv_window_conn` 和 `recv_window` (服务器端是 `recv_window_client`) 以确保它们至少不低于带宽-延迟的乘积。
 比如如果想在一条 RTT 200ms 的线路上达到 500 MB/s 的速度，receive window 至少需要 100 MB (500*0.2)
 
+### 路由器与其他嵌入式设备
+
+对于运算性能和内存十分有限的嵌入式设备，如果不是必须的话建议关闭混淆，可以带来少许性能提升。
+
+Hysteria 服务端与客户端默认的 receive window 大小是 64 MB。如果设备内存不够，请考虑通过配置降低。建议保持 stream receive window
+和 connection receive window 之间 1:4 的比例关系。
+
 ## 关于 ACL
 
 [ACL 文件格式](ACL.zh.md)