Index: main/rtp_engine.c
===================================================================
--- main/rtp_engine.c	(revision 380922)
+++ main/rtp_engine.c	(working copy)
@@ -1273,6 +1273,7 @@
 	enum ast_rtp_dtmf_mode dmode;
 	format_t codec0 = 0, codec1 = 0;
 	int unlock_chans = 1;
+	int read_ptime0, read_ptime1, write_ptime0, write_ptime1;
 
 	/* Lock both channels so we can look for the glue that binds them together */
 	ast_channel_lock(c0);
@@ -1352,6 +1353,18 @@
 		goto done;
 	}
 
+	read_ptime0 = (ast_codec_pref_getsize(&instance0->codecs.pref, c0->rawreadformat)).cur_ms;
+	read_ptime1 = (ast_codec_pref_getsize(&instance1->codecs.pref, c1->rawreadformat)).cur_ms;
+	write_ptime0 = (ast_codec_pref_getsize(&instance0->codecs.pref, c0->rawwriteformat)).cur_ms;
+	write_ptime1 = (ast_codec_pref_getsize(&instance1->codecs.pref, c1->rawwriteformat)).cur_ms;
+
+	if (read_ptime0 != write_ptime1 || read_ptime1 != write_ptime0) {
+		ast_debug(1, "Packetization differs between RTP streams (%d != %d or %d != %d). Cannot native bridge in RTP\n",
+				read_ptime0, write_ptime1, read_ptime1, write_ptime0);
+		res = AST_BRIDGE_FAILED_NOWARN;
+		goto done;
+	}
+
 	instance0->glue = glue0;
 	instance1->glue = glue1;
 	instance0->chan = c0;