diff --git a/codec/h264/lex.go b/codec/h264/lex.go
index a5b94bb8..cde1e2e0 100644
--- a/codec/h264/lex.go
+++ b/codec/h264/lex.go
@@ -159,8 +159,8 @@ outer:
 
 // Buffer sizes.
 const (
-	maxAUSize  = 100000
-	maxRTPSize = 4096
+	maxAUSize  = 100000 // Max access unit size in bytes.
+	maxRTPSize = 1500   // Max ethernet transmission unit in bytes.
 )
 
 // RTPLexer is a lexer for lexing H264 from RTP packets.