diff -Naur ppp-2.4.4-upto52/pppd/options.c ppp-2.4.4/pppd/options.c
--- ppp-2.4.4-upto52/pppd/options.c	2007-12-08 21:52:54 +0300
+++ ppp-2.4.4/pppd/options.c	2007-12-08 21:56:20 +0300
@@ -119,6 +119,7 @@
 bool	tune_kernel;		/* may alter kernel settings */
 int	connect_delay = 1000;	/* wait this many ms after connect script */
 int	req_unit = -1;		/* requested interface unit */
+int	req_minunit = -1;	/* requested minimal interface unit */
 char	req_ifname[MAXIFNAMELEN];	/* requested interface name */
 bool	multilink = 0;		/* Enable multilink operation */
 char	*bundle_name = NULL;	/* bundle name for multilink */
@@ -287,6 +288,9 @@
     { "unit", o_int, &req_unit,
       "PPP interface unit number to use if possible",
       OPT_PRIO | OPT_LLIMIT, 0, 0 },
+    { "minunit", o_int, &req_minunit,
+      "PPP interface minimal unit number",
+      OPT_PRIO | OPT_LLIMIT, 0, 0 },
 
     { "ifname", o_string, req_ifname,
       "Set PPP interface name",
diff -Naur ppp-2.4.4-upto52/pppd/pppd.8 ppp-2.4.4/pppd/pppd.8
--- ppp-2.4.4-upto52/pppd/pppd.8	2007-12-08 21:52:54 +0300
+++ ppp-2.4.4/pppd/pppd.8	2007-12-08 21:53:34 +0300
@@ -1051,6 +1051,12 @@
 Set the ppp interface name for outbound connections.  A failure to set the
 name will terminate the pppd.
 .TP
+.B minunit \fInum
+Such as unit, but always select bigger interface
+.TP
+.B minunit \fInum
+PPP interface minimal unit number. Such as unit, but always select bigger interface
+.TP
 .B updetach
 With this option, pppd will detach from its controlling terminal once
 it has successfully established the ppp connection (to the point where
diff -Naur ppp-2.4.4-upto52/pppd/pppd.h ppp-2.4.4/pppd/pppd.h
--- ppp-2.4.4-upto52/pppd/pppd.h	2007-12-08 21:52:54 +0300
+++ ppp-2.4.4/pppd/pppd.h	2007-12-08 21:55:46 +0300
@@ -87,6 +87,7 @@
 #define MAXARGS		1	/* max # args to a command */
 #define MAXNAMELEN	256	/* max length of hostname or name for auth */
 #define MAXSECRETLEN	256	/* max length of password or secret */
+#define MAXUNIT		255	/* max ppp interface */
 #define MAXIFNAMELEN	32	/* max length of interface name; or use IFNAMSIZ, can we
 				   always include net/if.h? */
 
@@ -329,6 +330,7 @@
 extern int	connect_delay;	/* Time to delay after connect script */
 extern int	max_data_rate;	/* max bytes/sec through charshunt */
 extern int	req_unit;	/* interface unit number to use */
+extern int	req_minunit;	/* interface minimal unit number to use */
 extern char	req_ifname[MAXIFNAMELEN];	/* interface name to use */
 extern bool	multilink;	/* enable multilink operation */
 extern bool	noendpoint;	/* don't send or accept endpt. discrim. */
diff -Naur ppp-2.4.4-upto52/pppd/sys-linux.c ppp-2.4.4/pppd/sys-linux.c
--- ppp-2.4.4-upto52/pppd/sys-linux.c	2007-12-08 21:52:54 +0300
+++ ppp-2.4.4/pppd/sys-linux.c	2007-12-08 21:53:34 +0300
@@ -630,13 +630,26 @@
 	    || fcntl(ppp_dev_fd, F_SETFL, flags | O_NONBLOCK) == -1)
 		warn("Couldn't set /dev/ppp to nonblock: %m");
 
-	ifunit = req_unit;
-	x = ioctl(ppp_dev_fd, PPPIOCNEWUNIT, &ifunit);
-	if (x < 0 && req_unit >= 0 && errno == EEXIST) {
+	if (req_minunit > -1) {
+	    for(ifunit = req_minunit;req_minunit < MAXUNIT; ifunit = ++req_minunit) {
+		x = ioctl(ppp_dev_fd, PPPIOCNEWUNIT, &ifunit);
+		if (x < 0 && errno == EEXIST) {
+		    warn("Couldn't allocate PPP unit %d as it is already in use try to attempt next", req_minunit);
+		}
+		if (x >= 0)
+		    break;
+	    }
+	}
+	if ((x < 0) || (req_minunit == -1)) {
+	    ifunit = req_unit;
+	    x = ioctl(ppp_dev_fd, PPPIOCNEWUNIT, &ifunit);
+	    if (x < 0 && req_unit >= 0 && errno == EEXIST) {
 		warn("Couldn't allocate PPP unit %d as it is already in use", req_unit);
 		ifunit = -1;
 		x = ioctl(ppp_dev_fd, PPPIOCNEWUNIT, &ifunit);
+	    }
 	}
+
 	if (x < 0)
 		error("Couldn't create new ppp unit: %m");