diff -Nru ppp-2.4.3.orig/pppd/auth.c ppp-2.4.3/pppd/auth.c
--- ppp-2.4.3.orig/pppd/auth.c	2006-08-27 17:09:25 +0300
+++ ppp-2.4.3/pppd/auth.c	2006-08-27 22:54:38 +0300
@@ -1123,7 +1123,6 @@
 check_maxoctets(arg)
     void *arg;
 {
-    int diff;
     unsigned int used;
 
     update_link_stats(ifunit);
@@ -1144,8 +1143,7 @@
 	    used = link_stats.bytes_in+link_stats.bytes_out;
 	    break;
     }
-    diff = maxoctets - used;
-    if(diff < 0) {
+    if (maxoctets <= used) {
 	notice("Traffic limit reached. Limit: %u Used: %u", maxoctets, used);
 	lcp_close(0, "Traffic limit");
 	need_holdoff = 0;