From c6d5c4aae0ff9f891ec9f734f6b44598e569c48d Mon Sep 17 00:00:00 2001
From: kangping <wgtdkp@google.com>
Date: Fri, 17 Jul 2020 02:17:02 +0800
Subject: [PATCH] [dtls] increase maximum length of DTLS application data
 (#5125)

This commit increases the maximum allowed length of DTLS application
data from 512 bytes to 1152 bytes.

The maximum possible length of application data is just around 512
bytes, and we observed that a Client Hello with cookie encoded in
RLY_RX.ntf message could be 520 bytes.
---
 src/core/meshcop/dtls.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/core/meshcop/dtls.hpp b/src/core/meshcop/dtls.hpp
index 8aebbc216..a3cc41411 100644
--- a/src/core/meshcop/dtls.hpp
+++ b/src/core/meshcop/dtls.hpp
@@ -351,7 +351,7 @@ private:
     {
         kGuardTimeNewConnectionMilli = 2000,
 #if !OPENTHREAD_CONFIG_COAP_SECURE_API_ENABLE
-        kApplicationDataMaxLength = 512,
+        kApplicationDataMaxLength = 1152,
 #else
         kApplicationDataMaxLength = OPENTHREAD_CONFIG_DTLS_APPLICATION_DATA_MAX_LENGTH,
 #endif