FS-3549 --resolve This patch will probably make it work but the bug is actually…

FS-3549 --resolve This patch will probably make it work but the bug is actually in the phone, the patch is simply tolerating the bad behaviour.  You are correct about the a=sendonly missing, this was fixed in a later revision of the polycom firmware.  I suggest that even if this patch works, that you update your phones to a newer firmware, preferably the most recent.

src/mod/endpoints/mod_sofia/sofia_glue.c

@@ -4345,7 +4345,9 @@ uint8_t sofia_glue_negotiate_sdp(switch_core_session_t *session, const char *r_s
 		}
 	}
 
-	if ((m = sdp->sdp_media) && (m->m_mode == sdp_sendonly || m->m_mode == sdp_inactive)) {
+	if ((m = sdp->sdp_media) && 
+		(m->m_mode == sdp_sendonly || m->m_mode == sdp_inactive || 
+		 (m->m_connections && m->m_connections->c_address && !strcmp(m->m_connections->c_address, "0.0.0.0")))) {
 		sendonly = 2;			/* global sendonly always wins */
 	}