Index: chan_sip.c
===================================================================
--- chan_sip.c	(revision 36460)
+++ chan_sip.c	(working copy)
@@ -3333,8 +3333,15 @@
 	switch (frame->frametype) {
 	case AST_FRAME_VOICE:
 		if (!(frame->subclass & ast->nativeformats)) {
-			ast_log(LOG_WARNING, "Asked to transmit frame type %d, while native formats is %d (read/write = %d/%d)\n",
-				frame->subclass, ast->nativeformats, ast->readformat, ast->writeformat);
+			char s1[512], s2[512], s3[512];
+			ast_log(LOG_WARNING, "Asked to transmit frame type %d, while native formats is %s(%d) read/write = %s(%d)/%s(%d)\n",
+				frame->subclass, 
+				ast_getformatname_multiple(s1, sizeof(s1)-1, ast->nativeformats & AST_FORMAT_AUDIO_MASK),
+				ast->nativeformats & AST_FORMAT_AUDIO_MASK,
+				ast_getformatname_multiple(s2, sizeof(s2)-1, ast->readformat),
+				ast->readformat,
+				ast_getformatname_multiple(s3, sizeof(s3)-1, ast->writeformat),
+				ast->writeformat);
 			return 0;
 		}
 		if (p) {