--- channels/chan_sip.c	(Asterisk 13.5.0)
+++ channels/chan_sip.c	(working copy)
@@ -12791,3 +12790,0 @@
-	} else if (ast_format_cmp(format, ast_format_ilbc) == AST_FORMAT_CMP_EQUAL) {
-		/* Add information about us using only 20/30 ms packetization */
-		ast_str_append(a_buf, 0, "a=fmtp:%d mode=%u\r\n", rtp_code, framing);