--- chan_sip.c.bak	2005-01-26 16:55:15.000000000 -0500
+++ chan_sip.c	2005-01-31 14:33:31.000000000 -0500
@@ -8986,6 +8986,66 @@
 	return 0;
 }
 
+static char *synopsis_inuse = "SIPInUse(username[,maxusagecount])";
+static char *descrip_inuse = 
+"SIPInUse(username[,maxusagecount])\n"
+"   Checks the inuse counter of SIP user and sets channel variable INUSE.\n"
+"If maxusagecount is given and inuse counter is less than maxusagecount,\n"
+"we continue to the next step. Otherwise if inuse counter is more or equal\n"
+"maxusagecount and if priority n+101 exists, then execution continues at\n"
+"that step, otherwise -1 is returned\n";
+
+static char *app_inuse = "SIPInUse";
+
+/* returns inuse counter for sip peer */
+static int sip_inuse(struct ast_channel *chan, void *data)
+{
+	char user_name[256];
+	struct sip_user *user;
+	char inuse_str[40];
+	char *maxcnt_str=NULL;
+	int maxcnt = 0;
+	int inuse = 0;
+	int ret = 0;
+	
+	if (data && !ast_strlen_zero(data)) {
+	   	strncpy(user_name,data,sizeof(user_name)-1);
+	   	maxcnt_str=strchr(user_name,'|');
+	   	if (maxcnt_str) {
+	   	   	*maxcnt_str='\0';
+	   	   	maxcnt_str++;
+	   	   	if (maxcnt_str && !ast_strlen_zero(maxcnt_str)) {
+	   	   		maxcnt=atoi(maxcnt_str);
+	   	   		if (maxcnt<0) {
+					ast_log(LOG_WARNING,"Invalid maxusagecount specified: %d\n",maxcnt);
+					maxcnt=0;
+				}
+			}
+		}
+	} else {
+		ast_log(LOG_WARNING, "This application requires the argument: sip username\n");
+		return 0;
+	}
+	ast_mutex_lock(&userl.lock);
+	user = find_user(user_name);
+	if (user) {
+	   	inuse=user->inUse;
+	   	if (maxcnt && inuse>=maxcnt) {
+	   		if (ast_exists_extension(chan, chan->context, chan->exten, chan->priority + 101, chan->callerid))
+	   			chan->priority += 100;
+			else
+				ret = -1;
+		}
+	} else {
+		ast_log(LOG_WARNING, "SIP user %s not found",user_name);
+	}
+	ast_mutex_unlock(&userl.lock);
+	snprintf(inuse_str,sizeof(inuse_str),"%d",inuse);
+	pbx_builtin_setvar_helper(chan,"INUSE",inuse_str);
+	
+	return ret;
+}
+
 static int sip_get_codec(struct ast_channel *chan)
 {
 	struct sip_pvt *p = chan->pvt->pvt;
@@ -9169,6 +9229,7 @@
 		sip_rtp.type = type;
 		ast_rtp_proto_register(&sip_rtp);
 		ast_register_application(app_dtmfmode, sip_dtmfmode, synopsis_dtmfmode, descrip_dtmfmode);
+		ast_register_application(app_inuse,sip_inuse,synopsis_inuse,descrip_inuse);
 		ast_mutex_lock(&peerl.lock);
 		for (peer = peerl.peers; peer; peer = peer->next)
 			sip_poke_peer(peer);
@@ -9191,6 +9252,7 @@
 	
 	/* First, take us out of the channel loop */
 	ast_unregister_application(app_dtmfmode);
+	ast_unregister_application(app_inuse);
 	ast_cli_unregister(&cli_show_users);
 	ast_cli_unregister(&cli_show_channels);
 	ast_cli_unregister(&cli_show_channel);