--- chan_mgcp.c.orig	2012-05-14 21:44:27.000000000 +0200
+++ chan_mgcp.c	2014-01-06 17:11:15.561305190 +0100
@@ -200,7 +200,8 @@
 
 static int adsi = 0;
 
-static unsigned int oseq;
+static unsigned int oseq_global = 0;
+AST_MUTEX_DEFINE_STATIC(oseq_lock);
 
 /*! Wait up to 16 seconds for first digit (FXO logic) */
 static int firstdigittimeout = 16000;
@@ -2111,7 +2112,7 @@
 	return 0;
 }
 
-static int init_req(struct mgcp_endpoint *p, struct mgcp_request *req, char *verb)
+static int init_req(struct mgcp_endpoint *p, struct mgcp_request *req, char *verb, unsigned int oseq)
 {
 	/* Initialize a response */
 	if (req->headers || req->len) {
@@ -2144,13 +2145,17 @@
 
 static int reqprep(struct mgcp_request *req, struct mgcp_endpoint *p, char *verb)
 {
+	unsigned int oseq;
 	memset(req, 0, sizeof(struct mgcp_request));
-	oseq++;
-	if (oseq > 999999999) {
-		oseq = 1;
-	}
-	init_req(p, req, verb);
-	return 0;
+	ast_mutex_lock(&oseq_lock);
+	oseq_global++;
+	if (oseq_global > 999999999) {
+		oseq_global = 1;
+	}
+	oseq = oseq_global;
+	ast_mutex_unlock(&oseq_lock);
+	init_req(p, req, verb, oseq);
+	return oseq;
 }
 
 static int transmit_response(struct mgcp_subchannel *sub, char *msg, struct mgcp_request *req, char *msgrest)
@@ -2288,6 +2293,7 @@
 	struct mgcp_endpoint *p = sub->parent;
 	struct ast_format tmpfmt;
 	struct ast_sockaddr sub_tmpdest_tmp;
+	unsigned int oseq;
 
 	if (ast_strlen_zero(sub->cxident) && rtp) {
 		/* We don't have a CXident yet, store the destination and
@@ -2324,7 +2330,7 @@
 	}
 
 
-	reqprep(&resp, p, "MDCX");
+	oseq = reqprep(&resp, p, "MDCX");
 	add_header(&resp, "C", sub->callid);
 	add_header(&resp, "L", local);
 	add_header(&resp, "M", mgcp_cxmodes[sub->cxmode]);
@@ -2346,6 +2352,7 @@
 	char tmp[80];
 	struct ast_format tmpfmt;
 	struct mgcp_endpoint *p = sub->parent;
+	unsigned int oseq;
 
 	ast_debug(3, "Creating connection for %s@%s-%d in cxmode: %s callid: %s\n",
 		 p->name, p->parent->name, sub->id, mgcp_cxmodes[sub->cxmode], sub->callid);
@@ -2372,7 +2379,7 @@
 		}
 	}
 	sub->sdpsent = 1;
-	reqprep(&resp, p, "CRCX");
+	oseq = reqprep(&resp, p, "CRCX");
 	add_header(&resp, "C", sub->callid);
 	add_header(&resp, "L", local);
 	add_header(&resp, "M", mgcp_cxmodes[sub->cxmode]);
@@ -2443,6 +2450,7 @@
 	char tmp[80];
 	struct ast_format tmpfmt;
 	struct mgcp_endpoint *p = sub->parent;
+	unsigned int oseq;
 
 	ast_copy_string(local, "p:20, s:off, e:on", sizeof(local));
 
@@ -2458,7 +2466,7 @@
 	ast_debug(3, "Creating connection for %s@%s-%d in cxmode: %s callid: %s\n",
 		    p->name, p->parent->name, sub->id, mgcp_cxmodes[sub->cxmode], sub->callid);
 	sub->sdpsent = 0;
-	reqprep(&resp, p, "CRCX");
+	oseq = reqprep(&resp, p, "CRCX");
 	add_header(&resp, "C", sub->callid);
 	add_header(&resp, "L", local);
 	add_header(&resp, "M", "inactive");
@@ -2475,11 +2483,12 @@
 {
 	struct mgcp_request resp;
 	struct mgcp_endpoint *p = sub->parent;
+	unsigned int oseq;
 
 	ast_debug(3, "MGCP Asked to indicate tone: %s on  %s@%s-%d in cxmode: %s\n",
 		tone, p->name, p->parent->name, sub->id, mgcp_cxmodes[sub->cxmode]);
 	ast_copy_string(p->curtone, tone, sizeof(p->curtone));
-	reqprep(&resp, p, "RQNT");
+	oseq = reqprep(&resp, p, "RQNT");
 	add_header(&resp, "X", p->rqnt_ident);
 	switch (p->hookstate) {
 	case MGCP_ONHOOK:
@@ -2506,6 +2515,7 @@
 	struct timeval t = ast_tvnow();
 	struct ast_tm tm;
 	struct mgcp_endpoint *p = sub->parent;
+	unsigned int oseq;
 
 	ast_localtime(&t, &tm, NULL);
 	n = callername;
@@ -2521,7 +2531,7 @@
 	snprintf(tone2, sizeof(tone2), "%s,L/ci(%02d/%02d/%02d/%02d,%s,%s)", tone,
 		tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, l, n);
 	ast_copy_string(p->curtone, tone, sizeof(p->curtone));
-	reqprep(&resp, p, "RQNT");
+	oseq = reqprep(&resp, p, "RQNT");
 	add_header(&resp, "X", p->rqnt_ident);
 	switch (p->hookstate) {
 	case MGCP_ONHOOK:
@@ -2550,6 +2560,7 @@
 	int fc = 1;
 	char local[256];
 	char tmp[80];
+	unsigned int oseq;
 
 	if (ast_strlen_zero(sub->cxident)) {
 		/* We don't have a CXident yet, store the destination and
@@ -2585,7 +2596,7 @@
 		}
 	}
 
-	reqprep(&resp, p, "MDCX");
+	oseq = reqprep(&resp, p, "MDCX");
 	add_header(&resp, "C", sub->callid);
 	if (!sub->sdpsent) {
 		add_header(&resp, "L", local);
@@ -2644,7 +2655,8 @@
 static int transmit_audit_endpoint(struct mgcp_endpoint *p)
 {
 	struct mgcp_request resp;
-	reqprep(&resp, p, "AUEP");
+	unsigned int oseq;
+	oseq = reqprep(&resp, p, "AUEP");
 	/* removed unknown param VS */
 	/*add_header(&resp, "F", "A,R,D,S,X,N,I,T,O,ES,E,MD,M");*/
 	add_header(&resp, "F", "A");
@@ -2658,10 +2670,11 @@
 {
 	struct mgcp_endpoint *p = sub->parent;
 	struct mgcp_request resp;
+	unsigned int oseq;
 
 	ast_debug(3, "Delete connection %s %s@%s-%d with new mode: %s on callid: %s\n",
 		sub->cxident, p->name, p->parent->name, sub->id, mgcp_cxmodes[sub->cxmode], sub->callid);
-	reqprep(&resp, p, "DLCX");
+	oseq = reqprep(&resp, p, "DLCX");
 	/* check if call id is avail */
 	if (sub->callid[0])
 		add_header(&resp, "C", sub->callid);
@@ -2679,10 +2692,11 @@
 static int transmit_connection_del_w_params(struct mgcp_endpoint *p, char *callid, char *cxident)
 {
 	struct mgcp_request resp;
+	unsigned int oseq;
 
 	ast_debug(3, "Delete connection %s %s@%s on callid: %s\n",
 		cxident ? cxident : "", p->name, p->parent->name, callid ? callid : "");
-	reqprep(&resp, p, "DLCX");
+	oseq = reqprep(&resp, p, "DLCX");
 	/* check if call id is avail */
 	if (callid && *callid)
 		add_header(&resp, "C", callid);