Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 12343)
+++ channels/chan_sip.c	(working copy)
@@ -661,6 +661,7 @@
 	unsigned int flags;			/*!< SIP_ flags */	
 	int timer_t1;				/*!< SIP timer T1, ms rtt */
 	unsigned int sipoptions;		/*!< Supported SIP sipoptions on the other end */
+	int silence_supp;			/*!< Show/Hide silenceSupp from header */
 	int capability;				/*!< Special capability (codec) */
 	int jointcapability;			/*!< Supported capability at both ends (codecs ) */
 	int peercapability;			/*!< Supported peer capability */
@@ -788,6 +789,7 @@
 	char cid_num[80];		/*!< Caller ID num */
 	char cid_name[80];		/*!< Caller ID name */
 	int callingpres;		/*!< Calling id presentation */
+        int silence_supp;               /*!< Show/Hide silenceSupp from header */
 	int inUse;			/*!< Number of calls in use */
 	int call_limit;			/*!< Limit of concurrent calls */
 	char vmexten[AST_MAX_EXTENSION]; /*!< Dialplan extension for MWI notify message*/
@@ -1907,6 +1909,7 @@
 	}
 
 	ast_copy_flags(r, peer, SIP_FLAGS_TO_COPY);
+	r->silence_supp = peer->silence_supp;
 	r->capability = peer->capability;
 	r->prefs = peer->prefs;
 	if (r->rtp) {
@@ -4609,9 +4612,10 @@
 				    &a_audio_next, &a_audio_left,
 				    debug);
 	}
-
-	ast_build_string(&a_audio_next, &a_audio_left, "a=silenceSupp:off - - - -\r\n");
-
+	/* Show hide silenceSupp from header */
+	if (p->silence_supp) {
+		ast_build_string(&a_audio_next, &a_audio_left, "a=silenceSupp:off - - - -\r\n");
+	}  
 	if ((m_audio_left < 2) || (m_video_left < 2) || (a_audio_left == 0) || (a_video_left == 0))
 		ast_log(LOG_WARNING, "SIP SDP may be truncated due to undersized buffer!!\n");
 
@@ -12068,6 +12072,7 @@
 	peer->pickupgroup = 0;
 	peer->maxms = default_qualify;
 	peer->prefs = default_prefs;
+	peer->silence_supp = TRUE;
 }
 
 /*! \brief Create temporary peer (used in autocreatepeer mode) */
@@ -12300,6 +12305,14 @@
 				ast_log(LOG_WARNING, "Qualification of peer '%s' should be 'yes', 'no', or a number of milliseconds at line %d of sip.conf\n", peer->name, v->lineno);
 				peer->maxms = 0;
 			}
+		} else if (!strcasecmp(v->name, "silencesupp")) {
+			if (!strcasecmp(v->value, "hide")) {
+				peer->silence_supp = FALSE;
+			} else if (!strcasecmp(v->value, "show")) {
+				peer->silence_supp = TRUE;
+			} else {
+				ast_log(LOG_WARNING, "silencesupp bad param on %s just use: 'show' or 'hide'\n", peer->name);
+			}
 		}
 	}
 	if (!ast_test_flag((&global_flags_page2), SIP_PAGE2_IGNOREREGEXPIRE) && ast_test_flag((&peer->flags_page2), SIP_PAGE2_DYNAMIC) && realtime) {