--- trunk/res/res_pjsip_sdp_rtp.c	2015-02-06 18:11:55.298513691 +0100
+++ trunk-fir/res/res_pjsip_sdp_rtp.c	2015-02-06 18:43:50.985531526 +0100
@@ -50,6 +50,7 @@
 #include "asterisk/sched.h"
 #include "asterisk/acl.h"
 #include "asterisk/sdp_srtp.h"
+#include "asterisk/format_cache.h"
 
 #include "asterisk/res_pjsip.h"
 #include "asterisk/res_pjsip_session.h"
@@ -953,6 +954,7 @@
 	RAII_VAR(struct ast_format_cap *, caps, NULL, ao2_cleanup);
 	enum ast_media_type media_type = stream_to_media_type(session_media->stream_type);
 	int use_override_prefs = ast_format_cap_count(session->req_caps);
+	pj_str_t pjbuf;
 
 	int direct_media_enabled = !ast_sockaddr_isnull(&session_media->direct_media_addr) &&
 		ast_format_cap_count(session->direct_media_cap);
@@ -1048,7 +1050,14 @@
 		if ((attr = generate_fmtp_attr(pool, format, rtp_code))) {
 			media->attr[media->attr_count++] = attr;
 		}
-
+		
+		if (ast_format_cmp(format, ast_format_vp8) == AST_FORMAT_CMP_EQUAL) {
+			pjbuf = pj_str("* ccm fir");
+			if ((attr = pjmedia_sdp_attr_create(pool, "rtcp-fb", &pjbuf))) {
+				media->attr[media->attr_count++] = attr;
+			}
+		}
+		
 		if (ast_format_get_maximum_ms(format) &&
 			((ast_format_get_maximum_ms(format) < max_packet_size) || !max_packet_size)) {
 			max_packet_size = ast_format_get_maximum_ms(format);