--- gprs_sgsn_before_patch.c	2014-05-23 11:14:48.121829000 +0200
+++ gprs_sgsn_patch.c	2014-05-23 11:15:48.229829001 +0200
@@ -361,7 +361,7 @@
 	uint32_t ptmsi;
 
 restart:
-	ptmsi = rand();
+	ptmsi = rand() | 0xc0000000; //because of GPRS IMSI ATTACH
 	llist_for_each_entry(mm, &sgsn_mm_ctxts, list) {
 		if (mm->p_tmsi == ptmsi)
 			goto restart;