CVE-2008-1897

@@ -1383,13 +1383,13 @@ static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
 #define NEW_ALLOW 	1
 #define NEW_FORCE 	2
 
-static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur)
+static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur, int full_frame)
 {
 	if ((cur->addr.sin_addr.s_addr == sin->sin_addr.s_addr) &&
 		(cur->addr.sin_port == sin->sin_port)) {
 		/* This is the main host */
-		if ((cur->peercallno == callno) ||
-			((dcallno == cur->callno) && !cur->peercallno)) {
+		if ( (cur->peercallno == 0 || cur->peercallno == callno) &&
+			 (full_frame ? dcallno == cur->callno : 1) ) {
 			/* That's us.  Be sure we keep track of the peer call number */
 			return 1;
 		}
@@ -1491,7 +1491,7 @@ static int make_trunk(unsigned short callno, int locked)
  *
  * \note Calling this function while holding another pvt lock can cause a deadlock.
  */
-static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked)
+static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked, int full_frame)
 {
 	int res = 0;
 	int x;
@@ -1503,7 +1503,7 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
@@ -1513,14 +1513,16 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
 			ast_mutex_unlock(&iaxsl[x]);
 		}
 	}
 	if ((res < 1) && (new >= NEW_ALLOW)) {
+		int start, found = 0;
+
 		/* It may seem odd that we look through the peer list for a name for
 		 * this *incoming* call.  Well, it is weird.  However, users don't
 		 * have an IP address/port number that we can match against.  So,
@@ -1529,15 +1531,29 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 		 * correct, but it will be changed if needed after authentication. */
 		if (!iax2_getpeername(*sin, host, sizeof(host)))
 			snprintf(host, sizeof(host), "%s:%d", ast_inet_ntoa(sin->sin_addr), ntohs(sin->sin_port));
+
 		now = ast_tvnow();
-		for (x=1;x<TRUNK_CALL_START;x++) {
+		start = 1 + (ast_random() % (TRUNK_CALL_START - 1));
+		for (x = start; 1; x++) {
+			if (x == TRUNK_CALL_START) {
+				x = 0;
+				continue;
+			}
+
 			/* Find first unused call number that hasn't been used in a while */
 			ast_mutex_lock(&iaxsl[x]);
-			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) break;
+			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) {
+				found = 1;
+				break;
+			}
 			ast_mutex_unlock(&iaxsl[x]);
+			
+			if (x == start - 1) {
+				break;
+			}
 		}
 		/* We've still got lock held if we found a spot */
-		if (x >= TRUNK_CALL_START) {
+		if (x == start - 1 && !found) {
 			ast_log(LOG_WARNING, "No more space\n");
 			return 0;
 		}
@@ -1575,14 +1591,14 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 	return res;
 }
 
-static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 0);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 0, full_frame);
 }
 
-static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 1);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 1, full_frame);
 }
 
 static void iax2_frame_free(struct iax_frame *fr)
@@ -7624,7 +7640,7 @@ static int socket_process_meta(int packet_len, struct ast_iax2_meta_hdr *meta, s
 		/* Stop if we don't have enough data */
 		if (len > packet_len)
 			break;
-		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd);
+		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd, 0);
 		if (!fr->callno)
 			continue;
 
@@ -7807,7 +7823,7 @@ static int socket_process(struct iax2_thread *thread)
 		}
 
 		/* This is a video frame, get call number */
-		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd, 0);
 		minivid = 1;
 	} else if ((meta->zeros == 0) && !(ntohs(meta->metacmd) & 0x8000))
 		return socket_process_meta(res, meta, &sin, fd, fr);
@@ -7842,7 +7858,7 @@ static int socket_process(struct iax2_thread *thread)
 	}
 
 	if (!fr->callno)
-		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd, ntohs(mh->callno) & IAX_FLAG_FULL);
 
 	if (fr->callno > 0)
 		ast_mutex_lock(&iaxsl[fr->callno]);
@@ -9424,7 +9440,7 @@ static int iax2_do_register(struct iax2_registry *reg)
 
 	if (!reg->callno) {
 		ast_debug(1, "Allocate call number\n");
-		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd);
+		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd, 0);
 		if (reg->callno < 1) {
 			ast_log(LOG_WARNING, "Unable to create call for registration\n");
 			return -1;
@@ -9475,7 +9491,7 @@ static int iax2_provision(struct sockaddr_in *end, int sockfd, char *dest, const
 	memset(&ied, 0, sizeof(ied));
 	iax_ie_append_raw(&ied, IAX_IE_PROVISIONING, provdata.buf, provdata.pos);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (!callno)
 		return -1;
 
@@ -9631,7 +9647,7 @@ static int iax2_poke_peer(struct iax2_peer *peer, int heldcall)
 	}
 	if (heldcall)
 		ast_mutex_unlock(&iaxsl[heldcall]);
-	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd);
+	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd, 0);
 	if (heldcall)
 		ast_mutex_lock(&iaxsl[heldcall]);
 	if (peer->callno < 1) {
@@ -9710,7 +9726,7 @@ static struct ast_channel *iax2_request(const char *type, int format, void *data
 	if (pds.port)
 		sin.sin_port = htons(atoi(pds.port));
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		*cause = AST_CAUSE_CONGESTION;
@@ -11083,7 +11099,7 @@ static int cache_get_callno_locked(const char *data)
 	ast_debug(1, "peer: %s, username: %s, password: %s, context: %s\n",
 		pds.peer, pds.username, pds.password, pds.context);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		return -1;

@@ -1383,13 +1383,13 @@ static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
 #define NEW_ALLOW 	1
 #define NEW_FORCE 	2
 
-static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur)
+static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur, int full_frame)
 {
 	if ((cur->addr.sin_addr.s_addr == sin->sin_addr.s_addr) &&
 		(cur->addr.sin_port == sin->sin_port)) {
 		/* This is the main host */
-		if ((cur->peercallno == callno) ||
-			((dcallno == cur->callno) && !cur->peercallno)) {
+		if ( (cur->peercallno == 0 || cur->peercallno == callno) &&
+			 (full_frame ? dcallno == cur->callno : 1) ) {
 			/* That's us.  Be sure we keep track of the peer call number */
 			return 1;
 		}
@@ -1491,7 +1491,7 @@ static int make_trunk(unsigned short callno, int locked)
  *
  * \note Calling this function while holding another pvt lock can cause a deadlock.
  */
-static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked)
+static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked, int full_frame)
 {
 	int res = 0;
 	int x;
@@ -1503,7 +1503,7 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
@@ -1513,14 +1513,16 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
 			ast_mutex_unlock(&iaxsl[x]);
 		}
 	}
 	if ((res < 1) && (new >= NEW_ALLOW)) {
+		int start, found = 0;
+
 		/* It may seem odd that we look through the peer list for a name for
 		 * this *incoming* call.  Well, it is weird.  However, users don't
 		 * have an IP address/port number that we can match against.  So,
@@ -1529,15 +1531,29 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 		 * correct, but it will be changed if needed after authentication. */
 		if (!iax2_getpeername(*sin, host, sizeof(host)))
 			snprintf(host, sizeof(host), "%s:%d", ast_inet_ntoa(sin->sin_addr), ntohs(sin->sin_port));
+
 		now = ast_tvnow();
-		for (x=1;x<TRUNK_CALL_START;x++) {
+		start = 1 + (ast_random() % (TRUNK_CALL_START - 1));
+		for (x = start; 1; x++) {
+			if (x == TRUNK_CALL_START) {
+				x = 0;
+				continue;
+			}
+
 			/* Find first unused call number that hasn't been used in a while */
 			ast_mutex_lock(&iaxsl[x]);
-			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) break;
+			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) {
+				found = 1;
+				break;
+			}
 			ast_mutex_unlock(&iaxsl[x]);
+			
+			if (x == start - 1) {
+				break;
+			}
 		}
 		/* We've still got lock held if we found a spot */
-		if (x >= TRUNK_CALL_START) {
+		if (x == start - 1 && !found) {
 			ast_log(LOG_WARNING, "No more space\n");
 			return 0;
 		}
@@ -1575,14 +1591,14 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 	return res;
 }
 
-static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 0);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 0, full_frame);
 }
 
-static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 1);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 1, full_frame);
 }
 
 static void iax2_frame_free(struct iax_frame *fr)
@@ -7624,7 +7640,7 @@ static int socket_process_meta(int packet_len, struct ast_iax2_meta_hdr *meta, s
 		/* Stop if we don't have enough data */
 		if (len > packet_len)
 			break;
-		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd);
+		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd, 0);
 		if (!fr->callno)
 			continue;
 
@@ -7807,7 +7823,7 @@ static int socket_process(struct iax2_thread *thread)
 		}
 
 		/* This is a video frame, get call number */
-		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd, 0);
 		minivid = 1;
 	} else if ((meta->zeros == 0) && !(ntohs(meta->metacmd) & 0x8000))
 		return socket_process_meta(res, meta, &sin, fd, fr);
@@ -7842,7 +7858,7 @@ static int socket_process(struct iax2_thread *thread)
 	}
 
 	if (!fr->callno)
-		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd, ntohs(mh->callno) & IAX_FLAG_FULL);
 
 	if (fr->callno > 0)
 		ast_mutex_lock(&iaxsl[fr->callno]);
@@ -9424,7 +9440,7 @@ static int iax2_do_register(struct iax2_registry *reg)
 
 	if (!reg->callno) {
 		ast_debug(1, "Allocate call number\n");
-		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd);
+		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd, 0);
 		if (reg->callno < 1) {
 			ast_log(LOG_WARNING, "Unable to create call for registration\n");
 			return -1;
@@ -9475,7 +9491,7 @@ static int iax2_provision(struct sockaddr_in *end, int sockfd, char *dest, const
 	memset(&ied, 0, sizeof(ied));
 	iax_ie_append_raw(&ied, IAX_IE_PROVISIONING, provdata.buf, provdata.pos);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (!callno)
 		return -1;
 
@@ -9631,7 +9647,7 @@ static int iax2_poke_peer(struct iax2_peer *peer, int heldcall)
 	}
 	if (heldcall)
 		ast_mutex_unlock(&iaxsl[heldcall]);
-	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd);
+	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd, 0);
 	if (heldcall)
 		ast_mutex_lock(&iaxsl[heldcall]);
 	if (peer->callno < 1) {
@@ -9710,7 +9726,7 @@ static struct ast_channel *iax2_request(const char *type, int format, void *data
 	if (pds.port)
 		sin.sin_port = htons(atoi(pds.port));
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		*cause = AST_CAUSE_CONGESTION;
@@ -11083,7 +11099,7 @@ static int cache_get_callno_locked(const char *data)
 	ast_debug(1, "peer: %s, username: %s, password: %s, context: %s\n",
 		pds.peer, pds.username, pds.password, pds.context);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		return -1;

@@ -1383,13 +1383,13 @@ static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
 #define NEW_ALLOW 	1
 #define NEW_FORCE 	2
 
-static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur)
+static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur, int full_frame)
 {
 	if ((cur->addr.sin_addr.s_addr == sin->sin_addr.s_addr) &&
 		(cur->addr.sin_port == sin->sin_port)) {
 		/* This is the main host */
-		if ((cur->peercallno == callno) ||
-			((dcallno == cur->callno) && !cur->peercallno)) {
+		if ( (cur->peercallno == 0 || cur->peercallno == callno) &&
+			 (full_frame ? dcallno == cur->callno : 1) ) {
 			/* That's us.  Be sure we keep track of the peer call number */
 			return 1;
 		}
@@ -1491,7 +1491,7 @@ static int make_trunk(unsigned short callno, int locked)
  *
  * \note Calling this function while holding another pvt lock can cause a deadlock.
  */
-static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked)
+static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked, int full_frame)
 {
 	int res = 0;
 	int x;
@@ -1503,7 +1503,7 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
@@ -1513,14 +1513,16 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
 			ast_mutex_unlock(&iaxsl[x]);
 		}
 	}
 	if ((res < 1) && (new >= NEW_ALLOW)) {
+		int start, found = 0;
+
 		/* It may seem odd that we look through the peer list for a name for
 		 * this *incoming* call.  Well, it is weird.  However, users don't
 		 * have an IP address/port number that we can match against.  So,
@@ -1529,15 +1531,29 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 		 * correct, but it will be changed if needed after authentication. */
 		if (!iax2_getpeername(*sin, host, sizeof(host)))
 			snprintf(host, sizeof(host), "%s:%d", ast_inet_ntoa(sin->sin_addr), ntohs(sin->sin_port));
+
 		now = ast_tvnow();
-		for (x=1;x<TRUNK_CALL_START;x++) {
+		start = 1 + (ast_random() % (TRUNK_CALL_START - 1));
+		for (x = start; 1; x++) {
+			if (x == TRUNK_CALL_START) {
+				x = 0;
+				continue;
+			}
+
 			/* Find first unused call number that hasn't been used in a while */
 			ast_mutex_lock(&iaxsl[x]);
-			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) break;
+			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) {
+				found = 1;
+				break;
+			}
 			ast_mutex_unlock(&iaxsl[x]);
+			
+			if (x == start - 1) {
+				break;
+			}
 		}
 		/* We've still got lock held if we found a spot */
-		if (x >= TRUNK_CALL_START) {
+		if (x == start - 1 && !found) {
 			ast_log(LOG_WARNING, "No more space\n");
 			return 0;
 		}
@@ -1575,14 +1591,14 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 	return res;
 }
 
-static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 0);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 0, full_frame);
 }
 
-static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 1);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 1, full_frame);
 }
 
 static void iax2_frame_free(struct iax_frame *fr)
@@ -7624,7 +7640,7 @@ static int socket_process_meta(int packet_len, struct ast_iax2_meta_hdr *meta, s
 		/* Stop if we don't have enough data */
 		if (len > packet_len)
 			break;
-		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd);
+		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd, 0);
 		if (!fr->callno)
 			continue;
 
@@ -7807,7 +7823,7 @@ static int socket_process(struct iax2_thread *thread)
 		}
 
 		/* This is a video frame, get call number */
-		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd, 0);
 		minivid = 1;
 	} else if ((meta->zeros == 0) && !(ntohs(meta->metacmd) & 0x8000))
 		return socket_process_meta(res, meta, &sin, fd, fr);
@@ -7842,7 +7858,7 @@ static int socket_process(struct iax2_thread *thread)
 	}
 
 	if (!fr->callno)
-		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd, ntohs(mh->callno) & IAX_FLAG_FULL);
 
 	if (fr->callno > 0)
 		ast_mutex_lock(&iaxsl[fr->callno]);
@@ -9424,7 +9440,7 @@ static int iax2_do_register(struct iax2_registry *reg)
 
 	if (!reg->callno) {
 		ast_debug(1, "Allocate call number\n");
-		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd);
+		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd, 0);
 		if (reg->callno < 1) {
 			ast_log(LOG_WARNING, "Unable to create call for registration\n");
 			return -1;
@@ -9475,7 +9491,7 @@ static int iax2_provision(struct sockaddr_in *end, int sockfd, char *dest, const
 	memset(&ied, 0, sizeof(ied));
 	iax_ie_append_raw(&ied, IAX_IE_PROVISIONING, provdata.buf, provdata.pos);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (!callno)
 		return -1;
 
@@ -9631,7 +9647,7 @@ static int iax2_poke_peer(struct iax2_peer *peer, int heldcall)
 	}
 	if (heldcall)
 		ast_mutex_unlock(&iaxsl[heldcall]);
-	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd);
+	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd, 0);
 	if (heldcall)
 		ast_mutex_lock(&iaxsl[heldcall]);
 	if (peer->callno < 1) {
@@ -9710,7 +9726,7 @@ static struct ast_channel *iax2_request(const char *type, int format, void *data
 	if (pds.port)
 		sin.sin_port = htons(atoi(pds.port));
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		*cause = AST_CAUSE_CONGESTION;
@@ -11083,7 +11099,7 @@ static int cache_get_callno_locked(const char *data)
 	ast_debug(1, "peer: %s, username: %s, password: %s, context: %s\n",
 		pds.peer, pds.username, pds.password, pds.context);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		return -1;

@@ -1383,13 +1383,13 @@ static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
 #define NEW_ALLOW 	1
 #define NEW_FORCE 	2
 
-static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur)
+static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur, int full_frame)
 {
 	if ((cur->addr.sin_addr.s_addr == sin->sin_addr.s_addr) &&
 		(cur->addr.sin_port == sin->sin_port)) {
 		/* This is the main host */
-		if ((cur->peercallno == callno) ||
-			((dcallno == cur->callno) && !cur->peercallno)) {
+		if ( (cur->peercallno == 0 || cur->peercallno == callno) &&
+			 (full_frame ? dcallno == cur->callno : 1) ) {
 			/* That's us.  Be sure we keep track of the peer call number */
 			return 1;
 		}
@@ -1491,7 +1491,7 @@ static int make_trunk(unsigned short callno, int locked)
  *
  * \note Calling this function while holding another pvt lock can cause a deadlock.
  */
-static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked)
+static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked, int full_frame)
 {
 	int res = 0;
 	int x;
@@ -1503,7 +1503,7 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
@@ -1513,14 +1513,16 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
 			ast_mutex_unlock(&iaxsl[x]);
 		}
 	}
 	if ((res < 1) && (new >= NEW_ALLOW)) {
+		int start, found = 0;
+
 		/* It may seem odd that we look through the peer list for a name for
 		 * this *incoming* call.  Well, it is weird.  However, users don't
 		 * have an IP address/port number that we can match against.  So,
@@ -1529,15 +1531,29 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 		 * correct, but it will be changed if needed after authentication. */
 		if (!iax2_getpeername(*sin, host, sizeof(host)))
 			snprintf(host, sizeof(host), "%s:%d", ast_inet_ntoa(sin->sin_addr), ntohs(sin->sin_port));
+
 		now = ast_tvnow();
-		for (x=1;x<TRUNK_CALL_START;x++) {
+		start = 1 + (ast_random() % (TRUNK_CALL_START - 1));
+		for (x = start; 1; x++) {
+			if (x == TRUNK_CALL_START) {
+				x = 0;
+				continue;
+			}
+
 			/* Find first unused call number that hasn't been used in a while */
 			ast_mutex_lock(&iaxsl[x]);
-			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) break;
+			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) {
+				found = 1;
+				break;
+			}
 			ast_mutex_unlock(&iaxsl[x]);
+			
+			if (x == start - 1) {
+				break;
+			}
 		}
 		/* We've still got lock held if we found a spot */
-		if (x >= TRUNK_CALL_START) {
+		if (x == start - 1 && !found) {
 			ast_log(LOG_WARNING, "No more space\n");
 			return 0;
 		}
@@ -1575,14 +1591,14 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 	return res;
 }
 
-static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 0);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 0, full_frame);
 }
 
-static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 1);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 1, full_frame);
 }
 
 static void iax2_frame_free(struct iax_frame *fr)
@@ -7624,7 +7640,7 @@ static int socket_process_meta(int packet_len, struct ast_iax2_meta_hdr *meta, s
 		/* Stop if we don't have enough data */
 		if (len > packet_len)
 			break;
-		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd);
+		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd, 0);
 		if (!fr->callno)
 			continue;
 
@@ -7807,7 +7823,7 @@ static int socket_process(struct iax2_thread *thread)
 		}
 
 		/* This is a video frame, get call number */
-		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd, 0);
 		minivid = 1;
 	} else if ((meta->zeros == 0) && !(ntohs(meta->metacmd) & 0x8000))
 		return socket_process_meta(res, meta, &sin, fd, fr);
@@ -7842,7 +7858,7 @@ static int socket_process(struct iax2_thread *thread)
 	}
 
 	if (!fr->callno)
-		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd, ntohs(mh->callno) & IAX_FLAG_FULL);
 
 	if (fr->callno > 0)
 		ast_mutex_lock(&iaxsl[fr->callno]);
@@ -9424,7 +9440,7 @@ static int iax2_do_register(struct iax2_registry *reg)
 
 	if (!reg->callno) {
 		ast_debug(1, "Allocate call number\n");
-		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd);
+		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd, 0);
 		if (reg->callno < 1) {
 			ast_log(LOG_WARNING, "Unable to create call for registration\n");
 			return -1;
@@ -9475,7 +9491,7 @@ static int iax2_provision(struct sockaddr_in *end, int sockfd, char *dest, const
 	memset(&ied, 0, sizeof(ied));
 	iax_ie_append_raw(&ied, IAX_IE_PROVISIONING, provdata.buf, provdata.pos);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (!callno)
 		return -1;
 
@@ -9631,7 +9647,7 @@ static int iax2_poke_peer(struct iax2_peer *peer, int heldcall)
 	}
 	if (heldcall)
 		ast_mutex_unlock(&iaxsl[heldcall]);
-	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd);
+	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd, 0);
 	if (heldcall)
 		ast_mutex_lock(&iaxsl[heldcall]);
 	if (peer->callno < 1) {
@@ -9710,7 +9726,7 @@ static struct ast_channel *iax2_request(const char *type, int format, void *data
 	if (pds.port)
 		sin.sin_port = htons(atoi(pds.port));
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		*cause = AST_CAUSE_CONGESTION;
@@ -11083,7 +11099,7 @@ static int cache_get_callno_locked(const char *data)
 	ast_debug(1, "peer: %s, username: %s, password: %s, context: %s\n",
 		pds.peer, pds.username, pds.password, pds.context);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		return -1;

@@ -1383,13 +1383,13 @@ static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
 #define NEW_ALLOW 	1
 #define NEW_FORCE 	2
 
-static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur)
+static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur, int full_frame)
 {
 	if ((cur->addr.sin_addr.s_addr == sin->sin_addr.s_addr) &&
 		(cur->addr.sin_port == sin->sin_port)) {
 		/* This is the main host */
-		if ((cur->peercallno == callno) ||
-			((dcallno == cur->callno) && !cur->peercallno)) {
+		if ( (cur->peercallno == 0 || cur->peercallno == callno) &&
+			 (full_frame ? dcallno == cur->callno : 1) ) {
 			/* That's us.  Be sure we keep track of the peer call number */
 			return 1;
 		}
@@ -1491,7 +1491,7 @@ static int make_trunk(unsigned short callno, int locked)
  *
  * \note Calling this function while holding another pvt lock can cause a deadlock.
  */
-static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked)
+static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked, int full_frame)
 {
 	int res = 0;
 	int x;
@@ -1503,7 +1503,7 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
@@ -1513,14 +1513,16 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
 			ast_mutex_unlock(&iaxsl[x]);
 		}
 	}
 	if ((res < 1) && (new >= NEW_ALLOW)) {
+		int start, found = 0;
+
 		/* It may seem odd that we look through the peer list for a name for
 		 * this *incoming* call.  Well, it is weird.  However, users don't
 		 * have an IP address/port number that we can match against.  So,
@@ -1529,15 +1531,29 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 		 * correct, but it will be changed if needed after authentication. */
 		if (!iax2_getpeername(*sin, host, sizeof(host)))
 			snprintf(host, sizeof(host), "%s:%d", ast_inet_ntoa(sin->sin_addr), ntohs(sin->sin_port));
+
 		now = ast_tvnow();
-		for (x=1;x<TRUNK_CALL_START;x++) {
+		start = 1 + (ast_random() % (TRUNK_CALL_START - 1));
+		for (x = start; 1; x++) {
+			if (x == TRUNK_CALL_START) {
+				x = 0;
+				continue;
+			}
+
 			/* Find first unused call number that hasn't been used in a while */
 			ast_mutex_lock(&iaxsl[x]);
-			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) break;
+			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) {
+				found = 1;
+				break;
+			}
 			ast_mutex_unlock(&iaxsl[x]);
+			
+			if (x == start - 1) {
+				break;
+			}
 		}
 		/* We've still got lock held if we found a spot */
-		if (x >= TRUNK_CALL_START) {
+		if (x == start - 1 && !found) {
 			ast_log(LOG_WARNING, "No more space\n");
 			return 0;
 		}
@@ -1575,14 +1591,14 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 	return res;
 }
 
-static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 0);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 0, full_frame);
 }
 
-static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 1);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 1, full_frame);
 }
 
 static void iax2_frame_free(struct iax_frame *fr)
@@ -7624,7 +7640,7 @@ static int socket_process_meta(int packet_len, struct ast_iax2_meta_hdr *meta, s
 		/* Stop if we don't have enough data */
 		if (len > packet_len)
 			break;
-		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd);
+		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd, 0);
 		if (!fr->callno)
 			continue;
 
@@ -7807,7 +7823,7 @@ static int socket_process(struct iax2_thread *thread)
 		}
 
 		/* This is a video frame, get call number */
-		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd, 0);
 		minivid = 1;
 	} else if ((meta->zeros == 0) && !(ntohs(meta->metacmd) & 0x8000))
 		return socket_process_meta(res, meta, &sin, fd, fr);
@@ -7842,7 +7858,7 @@ static int socket_process(struct iax2_thread *thread)
 	}
 
 	if (!fr->callno)
-		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd, ntohs(mh->callno) & IAX_FLAG_FULL);
 
 	if (fr->callno > 0)
 		ast_mutex_lock(&iaxsl[fr->callno]);
@@ -9424,7 +9440,7 @@ static int iax2_do_register(struct iax2_registry *reg)
 
 	if (!reg->callno) {
 		ast_debug(1, "Allocate call number\n");
-		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd);
+		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd, 0);
 		if (reg->callno < 1) {
 			ast_log(LOG_WARNING, "Unable to create call for registration\n");
 			return -1;
@@ -9475,7 +9491,7 @@ static int iax2_provision(struct sockaddr_in *end, int sockfd, char *dest, const
 	memset(&ied, 0, sizeof(ied));
 	iax_ie_append_raw(&ied, IAX_IE_PROVISIONING, provdata.buf, provdata.pos);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (!callno)
 		return -1;
 
@@ -9631,7 +9647,7 @@ static int iax2_poke_peer(struct iax2_peer *peer, int heldcall)
 	}
 	if (heldcall)
 		ast_mutex_unlock(&iaxsl[heldcall]);
-	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd);
+	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd, 0);
 	if (heldcall)
 		ast_mutex_lock(&iaxsl[heldcall]);
 	if (peer->callno < 1) {
@@ -9710,7 +9726,7 @@ static struct ast_channel *iax2_request(const char *type, int format, void *data
 	if (pds.port)
 		sin.sin_port = htons(atoi(pds.port));
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		*cause = AST_CAUSE_CONGESTION;
@@ -11083,7 +11099,7 @@ static int cache_get_callno_locked(const char *data)
 	ast_debug(1, "peer: %s, username: %s, password: %s, context: %s\n",
 		pds.peer, pds.username, pds.password, pds.context);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		return -1;

@@ -1383,13 +1383,13 @@ static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
 #define NEW_ALLOW 	1
 #define NEW_FORCE 	2
 
-static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur)
+static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur, int full_frame)
 {
 	if ((cur->addr.sin_addr.s_addr == sin->sin_addr.s_addr) &&
 		(cur->addr.sin_port == sin->sin_port)) {
 		/* This is the main host */
-		if ((cur->peercallno == callno) ||
-			((dcallno == cur->callno) && !cur->peercallno)) {
+		if ( (cur->peercallno == 0 || cur->peercallno == callno) &&
+			 (full_frame ? dcallno == cur->callno : 1) ) {
 			/* That's us.  Be sure we keep track of the peer call number */
 			return 1;
 		}
@@ -1491,7 +1491,7 @@ static int make_trunk(unsigned short callno, int locked)
  *
  * \note Calling this function while holding another pvt lock can cause a deadlock.
  */
-static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked)
+static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked, int full_frame)
 {
 	int res = 0;
 	int x;
@@ -1503,7 +1503,7 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
@@ -1513,14 +1513,16 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
 			ast_mutex_unlock(&iaxsl[x]);
 		}
 	}
 	if ((res < 1) && (new >= NEW_ALLOW)) {
+		int start, found = 0;
+
 		/* It may seem odd that we look through the peer list for a name for
 		 * this *incoming* call.  Well, it is weird.  However, users don't
 		 * have an IP address/port number that we can match against.  So,
@@ -1529,15 +1531,29 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 		 * correct, but it will be changed if needed after authentication. */
 		if (!iax2_getpeername(*sin, host, sizeof(host)))
 			snprintf(host, sizeof(host), "%s:%d", ast_inet_ntoa(sin->sin_addr), ntohs(sin->sin_port));
+
 		now = ast_tvnow();
-		for (x=1;x<TRUNK_CALL_START;x++) {
+		start = 1 + (ast_random() % (TRUNK_CALL_START - 1));
+		for (x = start; 1; x++) {
+			if (x == TRUNK_CALL_START) {
+				x = 0;
+				continue;
+			}
+
 			/* Find first unused call number that hasn't been used in a while */
 			ast_mutex_lock(&iaxsl[x]);
-			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) break;
+			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) {
+				found = 1;
+				break;
+			}
 			ast_mutex_unlock(&iaxsl[x]);
+			
+			if (x == start - 1) {
+				break;
+			}
 		}
 		/* We've still got lock held if we found a spot */
-		if (x >= TRUNK_CALL_START) {
+		if (x == start - 1 && !found) {
 			ast_log(LOG_WARNING, "No more space\n");
 			return 0;
 		}
@@ -1575,14 +1591,14 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 	return res;
 }
 
-static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 0);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 0, full_frame);
 }
 
-static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 1);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 1, full_frame);
 }
 
 static void iax2_frame_free(struct iax_frame *fr)
@@ -7624,7 +7640,7 @@ static int socket_process_meta(int packet_len, struct ast_iax2_meta_hdr *meta, s
 		/* Stop if we don't have enough data */
 		if (len > packet_len)
 			break;
-		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd);
+		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd, 0);
 		if (!fr->callno)
 			continue;
 
@@ -7807,7 +7823,7 @@ static int socket_process(struct iax2_thread *thread)
 		}
 
 		/* This is a video frame, get call number */
-		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd, 0);
 		minivid = 1;
 	} else if ((meta->zeros == 0) && !(ntohs(meta->metacmd) & 0x8000))
 		return socket_process_meta(res, meta, &sin, fd, fr);
@@ -7842,7 +7858,7 @@ static int socket_process(struct iax2_thread *thread)
 	}
 
 	if (!fr->callno)
-		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd, ntohs(mh->callno) & IAX_FLAG_FULL);
 
 	if (fr->callno > 0)
 		ast_mutex_lock(&iaxsl[fr->callno]);
@@ -9424,7 +9440,7 @@ static int iax2_do_register(struct iax2_registry *reg)
 
 	if (!reg->callno) {
 		ast_debug(1, "Allocate call number\n");
-		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd);
+		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd, 0);
 		if (reg->callno < 1) {
 			ast_log(LOG_WARNING, "Unable to create call for registration\n");
 			return -1;
@@ -9475,7 +9491,7 @@ static int iax2_provision(struct sockaddr_in *end, int sockfd, char *dest, const
 	memset(&ied, 0, sizeof(ied));
 	iax_ie_append_raw(&ied, IAX_IE_PROVISIONING, provdata.buf, provdata.pos);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (!callno)
 		return -1;
 
@@ -9631,7 +9647,7 @@ static int iax2_poke_peer(struct iax2_peer *peer, int heldcall)
 	}
 	if (heldcall)
 		ast_mutex_unlock(&iaxsl[heldcall]);
-	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd);
+	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd, 0);
 	if (heldcall)
 		ast_mutex_lock(&iaxsl[heldcall]);
 	if (peer->callno < 1) {
@@ -9710,7 +9726,7 @@ static struct ast_channel *iax2_request(const char *type, int format, void *data
 	if (pds.port)
 		sin.sin_port = htons(atoi(pds.port));
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		*cause = AST_CAUSE_CONGESTION;
@@ -11083,7 +11099,7 @@ static int cache_get_callno_locked(const char *data)
 	ast_debug(1, "peer: %s, username: %s, password: %s, context: %s\n",
 		pds.peer, pds.username, pds.password, pds.context);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		return -1;

@@ -1383,13 +1383,13 @@ static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
 #define NEW_ALLOW 	1
 #define NEW_FORCE 	2
 
-static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur)
+static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur, int full_frame)
 {
 	if ((cur->addr.sin_addr.s_addr == sin->sin_addr.s_addr) &&
 		(cur->addr.sin_port == sin->sin_port)) {
 		/* This is the main host */
-		if ((cur->peercallno == callno) ||
-			((dcallno == cur->callno) && !cur->peercallno)) {
+		if ( (cur->peercallno == 0 || cur->peercallno == callno) &&
+			 (full_frame ? dcallno == cur->callno : 1) ) {
 			/* That's us.  Be sure we keep track of the peer call number */
 			return 1;
 		}
@@ -1491,7 +1491,7 @@ static int make_trunk(unsigned short callno, int locked)
  *
  * \note Calling this function while holding another pvt lock can cause a deadlock.
  */
-static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked)
+static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked, int full_frame)
 {
 	int res = 0;
 	int x;
@@ -1503,7 +1503,7 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
@@ -1513,14 +1513,16 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
 			ast_mutex_unlock(&iaxsl[x]);
 		}
 	}
 	if ((res < 1) && (new >= NEW_ALLOW)) {
+		int start, found = 0;
+
 		/* It may seem odd that we look through the peer list for a name for
 		 * this *incoming* call.  Well, it is weird.  However, users don't
 		 * have an IP address/port number that we can match against.  So,
@@ -1529,15 +1531,29 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 		 * correct, but it will be changed if needed after authentication. */
 		if (!iax2_getpeername(*sin, host, sizeof(host)))
 			snprintf(host, sizeof(host), "%s:%d", ast_inet_ntoa(sin->sin_addr), ntohs(sin->sin_port));
+
 		now = ast_tvnow();
-		for (x=1;x<TRUNK_CALL_START;x++) {
+		start = 1 + (ast_random() % (TRUNK_CALL_START - 1));
+		for (x = start; 1; x++) {
+			if (x == TRUNK_CALL_START) {
+				x = 0;
+				continue;
+			}
+
 			/* Find first unused call number that hasn't been used in a while */
 			ast_mutex_lock(&iaxsl[x]);
-			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) break;
+			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) {
+				found = 1;
+				break;
+			}
 			ast_mutex_unlock(&iaxsl[x]);
+			
+			if (x == start - 1) {
+				break;
+			}
 		}
 		/* We've still got lock held if we found a spot */
-		if (x >= TRUNK_CALL_START) {
+		if (x == start - 1 && !found) {
 			ast_log(LOG_WARNING, "No more space\n");
 			return 0;
 		}
@@ -1575,14 +1591,14 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 	return res;
 }
 
-static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 0);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 0, full_frame);
 }
 
-static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 1);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 1, full_frame);
 }
 
 static void iax2_frame_free(struct iax_frame *fr)
@@ -7624,7 +7640,7 @@ static int socket_process_meta(int packet_len, struct ast_iax2_meta_hdr *meta, s
 		/* Stop if we don't have enough data */
 		if (len > packet_len)
 			break;
-		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd);
+		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd, 0);
 		if (!fr->callno)
 			continue;
 
@@ -7807,7 +7823,7 @@ static int socket_process(struct iax2_thread *thread)
 		}
 
 		/* This is a video frame, get call number */
-		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd, 0);
 		minivid = 1;
 	} else if ((meta->zeros == 0) && !(ntohs(meta->metacmd) & 0x8000))
 		return socket_process_meta(res, meta, &sin, fd, fr);
@@ -7842,7 +7858,7 @@ static int socket_process(struct iax2_thread *thread)
 	}
 
 	if (!fr->callno)
-		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd, ntohs(mh->callno) & IAX_FLAG_FULL);
 
 	if (fr->callno > 0)
 		ast_mutex_lock(&iaxsl[fr->callno]);
@@ -9424,7 +9440,7 @@ static int iax2_do_register(struct iax2_registry *reg)
 
 	if (!reg->callno) {
 		ast_debug(1, "Allocate call number\n");
-		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd);
+		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd, 0);
 		if (reg->callno < 1) {
 			ast_log(LOG_WARNING, "Unable to create call for registration\n");
 			return -1;
@@ -9475,7 +9491,7 @@ static int iax2_provision(struct sockaddr_in *end, int sockfd, char *dest, const
 	memset(&ied, 0, sizeof(ied));
 	iax_ie_append_raw(&ied, IAX_IE_PROVISIONING, provdata.buf, provdata.pos);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (!callno)
 		return -1;
 
@@ -9631,7 +9647,7 @@ static int iax2_poke_peer(struct iax2_peer *peer, int heldcall)
 	}
 	if (heldcall)
 		ast_mutex_unlock(&iaxsl[heldcall]);
-	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd);
+	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd, 0);
 	if (heldcall)
 		ast_mutex_lock(&iaxsl[heldcall]);
 	if (peer->callno < 1) {
@@ -9710,7 +9726,7 @@ static struct ast_channel *iax2_request(const char *type, int format, void *data
 	if (pds.port)
 		sin.sin_port = htons(atoi(pds.port));
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		*cause = AST_CAUSE_CONGESTION;
@@ -11083,7 +11099,7 @@ static int cache_get_callno_locked(const char *data)
 	ast_debug(1, "peer: %s, username: %s, password: %s, context: %s\n",
 		pds.peer, pds.username, pds.password, pds.context);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		return -1;

@@ -1383,13 +1383,13 @@ static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
 #define NEW_ALLOW 	1
 #define NEW_FORCE 	2
 
-static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur)
+static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur, int full_frame)
 {
 	if ((cur->addr.sin_addr.s_addr == sin->sin_addr.s_addr) &&
 		(cur->addr.sin_port == sin->sin_port)) {
 		/* This is the main host */
-		if ((cur->peercallno == callno) ||
-			((dcallno == cur->callno) && !cur->peercallno)) {
+		if ( (cur->peercallno == 0 || cur->peercallno == callno) &&
+			 (full_frame ? dcallno == cur->callno : 1) ) {
 			/* That's us.  Be sure we keep track of the peer call number */
 			return 1;
 		}
@@ -1491,7 +1491,7 @@ static int make_trunk(unsigned short callno, int locked)
  *
  * \note Calling this function while holding another pvt lock can cause a deadlock.
  */
-static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked)
+static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked, int full_frame)
 {
 	int res = 0;
 	int x;
@@ -1503,7 +1503,7 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
@@ -1513,14 +1513,16 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
 			ast_mutex_unlock(&iaxsl[x]);
 		}
 	}
 	if ((res < 1) && (new >= NEW_ALLOW)) {
+		int start, found = 0;
+
 		/* It may seem odd that we look through the peer list for a name for
 		 * this *incoming* call.  Well, it is weird.  However, users don't
 		 * have an IP address/port number that we can match against.  So,
@@ -1529,15 +1531,29 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 		 * correct, but it will be changed if needed after authentication. */
 		if (!iax2_getpeername(*sin, host, sizeof(host)))
 			snprintf(host, sizeof(host), "%s:%d", ast_inet_ntoa(sin->sin_addr), ntohs(sin->sin_port));
+
 		now = ast_tvnow();
-		for (x=1;x<TRUNK_CALL_START;x++) {
+		start = 1 + (ast_random() % (TRUNK_CALL_START - 1));
+		for (x = start; 1; x++) {
+			if (x == TRUNK_CALL_START) {
+				x = 0;
+				continue;
+			}
+
 			/* Find first unused call number that hasn't been used in a while */
 			ast_mutex_lock(&iaxsl[x]);
-			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) break;
+			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) {
+				found = 1;
+				break;
+			}
 			ast_mutex_unlock(&iaxsl[x]);
+			
+			if (x == start - 1) {
+				break;
+			}
 		}
 		/* We've still got lock held if we found a spot */
-		if (x >= TRUNK_CALL_START) {
+		if (x == start - 1 && !found) {
 			ast_log(LOG_WARNING, "No more space\n");
 			return 0;
 		}
@@ -1575,14 +1591,14 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 	return res;
 }
 
-static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 0);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 0, full_frame);
 }
 
-static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 1);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 1, full_frame);
 }
 
 static void iax2_frame_free(struct iax_frame *fr)
@@ -7624,7 +7640,7 @@ static int socket_process_meta(int packet_len, struct ast_iax2_meta_hdr *meta, s
 		/* Stop if we don't have enough data */
 		if (len > packet_len)
 			break;
-		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd);
+		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd, 0);
 		if (!fr->callno)
 			continue;
 
@@ -7807,7 +7823,7 @@ static int socket_process(struct iax2_thread *thread)
 		}
 
 		/* This is a video frame, get call number */
-		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd, 0);
 		minivid = 1;
 	} else if ((meta->zeros == 0) && !(ntohs(meta->metacmd) & 0x8000))
 		return socket_process_meta(res, meta, &sin, fd, fr);
@@ -7842,7 +7858,7 @@ static int socket_process(struct iax2_thread *thread)
 	}
 
 	if (!fr->callno)
-		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd, ntohs(mh->callno) & IAX_FLAG_FULL);
 
 	if (fr->callno > 0)
 		ast_mutex_lock(&iaxsl[fr->callno]);
@@ -9424,7 +9440,7 @@ static int iax2_do_register(struct iax2_registry *reg)
 
 	if (!reg->callno) {
 		ast_debug(1, "Allocate call number\n");
-		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd);
+		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd, 0);
 		if (reg->callno < 1) {
 			ast_log(LOG_WARNING, "Unable to create call for registration\n");
 			return -1;
@@ -9475,7 +9491,7 @@ static int iax2_provision(struct sockaddr_in *end, int sockfd, char *dest, const
 	memset(&ied, 0, sizeof(ied));
 	iax_ie_append_raw(&ied, IAX_IE_PROVISIONING, provdata.buf, provdata.pos);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (!callno)
 		return -1;
 
@@ -9631,7 +9647,7 @@ static int iax2_poke_peer(struct iax2_peer *peer, int heldcall)
 	}
 	if (heldcall)
 		ast_mutex_unlock(&iaxsl[heldcall]);
-	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd);
+	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd, 0);
 	if (heldcall)
 		ast_mutex_lock(&iaxsl[heldcall]);
 	if (peer->callno < 1) {
@@ -9710,7 +9726,7 @@ static struct ast_channel *iax2_request(const char *type, int format, void *data
 	if (pds.port)
 		sin.sin_port = htons(atoi(pds.port));
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		*cause = AST_CAUSE_CONGESTION;
@@ -11083,7 +11099,7 @@ static int cache_get_callno_locked(const char *data)
 	ast_debug(1, "peer: %s, username: %s, password: %s, context: %s\n",
 		pds.peer, pds.username, pds.password, pds.context);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		return -1;

@@ -1383,13 +1383,13 @@ static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
 #define NEW_ALLOW 	1
 #define NEW_FORCE 	2
 
-static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur)
+static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, const struct chan_iax2_pvt *cur, int full_frame)
 {
 	if ((cur->addr.sin_addr.s_addr == sin->sin_addr.s_addr) &&
 		(cur->addr.sin_port == sin->sin_port)) {
 		/* This is the main host */
-		if ((cur->peercallno == callno) ||
-			((dcallno == cur->callno) && !cur->peercallno)) {
+		if ( (cur->peercallno == 0 || cur->peercallno == callno) &&
+			 (full_frame ? dcallno == cur->callno : 1) ) {
 			/* That's us.  Be sure we keep track of the peer call number */
 			return 1;
 		}
@@ -1491,7 +1491,7 @@ static int make_trunk(unsigned short callno, int locked)
  *
  * \note Calling this function while holding another pvt lock can cause a deadlock.
  */
-static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked)
+static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked, int full_frame)
 {
 	int res = 0;
 	int x;
@@ -1503,7 +1503,7 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
@@ -1513,14 +1513,16 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
 			ast_mutex_unlock(&iaxsl[x]);
 		}
 	}
 	if ((res < 1) && (new >= NEW_ALLOW)) {
+		int start, found = 0;
+
 		/* It may seem odd that we look through the peer list for a name for
 		 * this *incoming* call.  Well, it is weird.  However, users don't
 		 * have an IP address/port number that we can match against.  So,
@@ -1529,15 +1531,29 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 		 * correct, but it will be changed if needed after authentication. */
 		if (!iax2_getpeername(*sin, host, sizeof(host)))
 			snprintf(host, sizeof(host), "%s:%d", ast_inet_ntoa(sin->sin_addr), ntohs(sin->sin_port));
+
 		now = ast_tvnow();
-		for (x=1;x<TRUNK_CALL_START;x++) {
+		start = 1 + (ast_random() % (TRUNK_CALL_START - 1));
+		for (x = start; 1; x++) {
+			if (x == TRUNK_CALL_START) {
+				x = 0;
+				continue;
+			}
+
 			/* Find first unused call number that hasn't been used in a while */
 			ast_mutex_lock(&iaxsl[x]);
-			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) break;
+			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) {
+				found = 1;
+				break;
+			}
 			ast_mutex_unlock(&iaxsl[x]);
+			
+			if (x == start - 1) {
+				break;
+			}
 		}
 		/* We've still got lock held if we found a spot */
-		if (x >= TRUNK_CALL_START) {
+		if (x == start - 1 && !found) {
 			ast_log(LOG_WARNING, "No more space\n");
 			return 0;
 		}
@@ -1575,14 +1591,14 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 	return res;
 }
 
-static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 0);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 0, full_frame);
 }
 
-static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 1);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 1, full_frame);
 }
 
 static void iax2_frame_free(struct iax_frame *fr)
@@ -7624,7 +7640,7 @@ static int socket_process_meta(int packet_len, struct ast_iax2_meta_hdr *meta, s
 		/* Stop if we don't have enough data */
 		if (len > packet_len)
 			break;
-		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd);
+		fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, sin, NEW_PREVENT, sockfd, 0);
 		if (!fr->callno)
 			continue;
 
@@ -7807,7 +7823,7 @@ static int socket_process(struct iax2_thread *thread)
 		}
 
 		/* This is a video frame, get call number */
-		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd, 0);
 		minivid = 1;
 	} else if ((meta->zeros == 0) && !(ntohs(meta->metacmd) & 0x8000))
 		return socket_process_meta(res, meta, &sin, fd, fr);
@@ -7842,7 +7858,7 @@ static int socket_process(struct iax2_thread *thread)
 	}
 
 	if (!fr->callno)
-		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd, ntohs(mh->callno) & IAX_FLAG_FULL);
 
 	if (fr->callno > 0)
 		ast_mutex_lock(&iaxsl[fr->callno]);
@@ -9424,7 +9440,7 @@ static int iax2_do_register(struct iax2_registry *reg)
 
 	if (!reg->callno) {
 		ast_debug(1, "Allocate call number\n");
-		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd);
+		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd, 0);
 		if (reg->callno < 1) {
 			ast_log(LOG_WARNING, "Unable to create call for registration\n");
 			return -1;
@@ -9475,7 +9491,7 @@ static int iax2_provision(struct sockaddr_in *end, int sockfd, char *dest, const
 	memset(&ied, 0, sizeof(ied));
 	iax_ie_append_raw(&ied, IAX_IE_PROVISIONING, provdata.buf, provdata.pos);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (!callno)
 		return -1;
 
@@ -9631,7 +9647,7 @@ static int iax2_poke_peer(struct iax2_peer *peer, int heldcall)
 	}
 	if (heldcall)
 		ast_mutex_unlock(&iaxsl[heldcall]);
-	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd);
+	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd, 0);
 	if (heldcall)
 		ast_mutex_lock(&iaxsl[heldcall]);
 	if (peer->callno < 1) {
@@ -9710,7 +9726,7 @@ static struct ast_channel *iax2_request(const char *type, int format, void *data
 	if (pds.port)
 		sin.sin_port = htons(atoi(pds.port));
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		*cause = AST_CAUSE_CONGESTION;
@@ -11083,7 +11099,7 @@ static int cache_get_callno_locked(const char *data)
 	ast_debug(1, "peer: %s, username: %s, password: %s, context: %s\n",
 		pds.peer, pds.username, pds.password, pds.context);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		return -1;

@@ -1239,13 +1239,13 @@ static struct iax_frame *iaxfrdup2(struct iax_frame *fr)
 #define NEW_ALLOW 	1
 #define NEW_FORCE 	2
 
-static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, struct chan_iax2_pvt *cur)
+static int match(struct sockaddr_in *sin, unsigned short callno, unsigned short dcallno, struct chan_iax2_pvt *cur, int full_frame)
 {
 	if ((cur->addr.sin_addr.s_addr == sin->sin_addr.s_addr) &&
 		(cur->addr.sin_port == sin->sin_port)) {
 		/* This is the main host */
-		if ((cur->peercallno == callno) ||
-			((dcallno == cur->callno) && !cur->peercallno)) {
+		if ( (cur->peercallno == 0 || cur->peercallno == callno) &&
+			 (full_frame ? dcallno == cur->callno : 1) ) {
 			/* That's us.  Be sure we keep track of the peer call number */
 			return 1;
 		}
@@ -1336,7 +1336,7 @@ static int make_trunk(unsigned short callno, int locked)
 /*!
  * \note Calling this function while holding another pvt lock can cause a deadlock.
  */
-static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked)
+static int __find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int return_locked, int full_frame)
 {
 	int res = 0;
 	int x;
@@ -1349,7 +1349,7 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
@@ -1359,14 +1359,16 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 			ast_mutex_lock(&iaxsl[x]);
 			if (iaxs[x]) {
 				/* Look for an exact match */
-				if (match(sin, callno, dcallno, iaxs[x])) {
+				if (match(sin, callno, dcallno, iaxs[x], full_frame)) {
 					res = x;
 				}
 			}
 			ast_mutex_unlock(&iaxsl[x]);
 		}
 	}
 	if ((res < 1) && (new >= NEW_ALLOW)) {
+		int start, found = 0;
+
 		/* It may seem odd that we look through the peer list for a name for
 		 * this *incoming* call.  Well, it is weird.  However, users don't
 		 * have an IP address/port number that we can match against.  So,
@@ -1375,15 +1377,29 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 		 * correct, but it will be changed if needed after authentication. */
 		if (!iax2_getpeername(*sin, host, sizeof(host)))
 			snprintf(host, sizeof(host), "%s:%d", ast_inet_ntoa(sin->sin_addr), ntohs(sin->sin_port));
-		gettimeofday(&now, NULL);
-		for (x=1;x<TRUNK_CALL_START;x++) {
+
+		now = ast_tvnow();
+		start = 1 + (ast_random() % (TRUNK_CALL_START - 1));
+		for (x = start; 1; x++) {
+			if (x == TRUNK_CALL_START) {
+				x = 0;
+				continue;
+			}
+
 			/* Find first unused call number that hasn't been used in a while */
 			ast_mutex_lock(&iaxsl[x]);
-			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) break;
+			if (!iaxs[x] && ((now.tv_sec - lastused[x].tv_sec) > MIN_REUSE_TIME)) {
+				found = 1;
+				break;
+			}
 			ast_mutex_unlock(&iaxsl[x]);
+			
+			if (x == start - 1) {
+				break;
+			}
 		}
 		/* We've still got lock held if we found a spot */
-		if (x >= TRUNK_CALL_START) {
+		if (x == start - 1 && !found) {
 			ast_log(LOG_WARNING, "No more space\n");
 			return 0;
 		}
@@ -1420,14 +1436,14 @@ static int __find_callno(unsigned short callno, unsigned short dcallno, struct s
 	return res;
 }
 
-static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 0);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 0, full_frame);
 }
 
-static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd) {
+static int find_callno_locked(unsigned short callno, unsigned short dcallno, struct sockaddr_in *sin, int new, int sockfd, int full_frame) {
 
-	return __find_callno(callno, dcallno, sin, new, sockfd, 1);
+	return __find_callno(callno, dcallno, sin, new, sockfd, 1, full_frame);
 }
 
 static void iax2_frame_free(struct iax_frame *fr)
@@ -6871,7 +6887,7 @@ static int socket_process(struct iax2_thread *thread)
 		}
 
 		/* This is a video frame, get call number */
-		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(vh->callno) & ~0x8000, dcallno, &sin, new, fd, 0);
 		minivid = 1;
 	} else if ((meta->zeros == 0) && !(ntohs(meta->metacmd) & 0x8000)) {
 		unsigned char metatype;
@@ -6929,7 +6945,7 @@ static int socket_process(struct iax2_thread *thread)
 				/* Stop if we don't have enough data */
 				if (len > res)
 					break;
-				fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, &sin, NEW_PREVENT, fd);
+				fr->callno = find_callno_locked(callno & ~IAX_FLAG_FULL, 0, &sin, NEW_PREVENT, fd, 0);
 				if (fr->callno) {
 					/* If it's a valid call, deliver the contents.  If not, we
 					   drop it, since we don't have a scallno to use for an INVAL */
@@ -7015,7 +7031,7 @@ static int socket_process(struct iax2_thread *thread)
 	}
 
 	if (!fr->callno)
-		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd);
+		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, fd, ntohs(mh->callno) & IAX_FLAG_FULL);
 
 	if (fr->callno > 0)
 		ast_mutex_lock(&iaxsl[fr->callno]);
@@ -8510,7 +8526,7 @@ static int iax2_do_register(struct iax2_registry *reg)
 	if (!reg->callno) {
 		if (option_debug)
 			ast_log(LOG_DEBUG, "Allocate call number\n");
-		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd);
+		reg->callno = find_callno_locked(0, 0, &reg->addr, NEW_FORCE, defaultsockfd, 0);
 		if (reg->callno < 1) {
 			ast_log(LOG_WARNING, "Unable to create call for registration\n");
 			return -1;
@@ -8571,7 +8587,7 @@ static int iax2_provision(struct sockaddr_in *end, int sockfd, char *dest, const
 	memset(&ied, 0, sizeof(ied));
 	iax_ie_append_raw(&ied, IAX_IE_PROVISIONING, provdata.buf, provdata.pos);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (!callno)
 		return -1;
 
@@ -8712,7 +8728,7 @@ static int iax2_poke_peer(struct iax2_peer *peer, int heldcall)
 	}
 	if (heldcall)
 		ast_mutex_unlock(&iaxsl[heldcall]);
-	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd);
+	peer->callno = find_callno(0, 0, &peer->addr, NEW_FORCE, peer->sockfd, 0);
 	if (heldcall)
 		ast_mutex_lock(&iaxsl[heldcall]);
 	if (peer->callno < 1) {
@@ -8792,7 +8808,7 @@ static struct ast_channel *iax2_request(const char *type, int format, void *data
 	if (pds.port)
 		sin.sin_port = htons(atoi(pds.port));
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		*cause = AST_CAUSE_CONGESTION;
@@ -10106,7 +10122,7 @@ static int cache_get_callno_locked(const char *data)
 		ast_log(LOG_DEBUG, "peer: %s, username: %s, password: %s, context: %s\n",
 			pds.peer, pds.username, pds.password, pds.context);
 
-	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd);
+	callno = find_callno_locked(0, 0, &sin, NEW_FORCE, cai.sockfd, 0);
 	if (callno < 1) {
 		ast_log(LOG_WARNING, "Unable to create call\n");
 		return -1;