diff -ru asterisk-original/channels/chan_sip.c asterisk/channels/chan_sip.c
--- asterisk-original/channels/chan_sip.c	2008-01-02 11:43:07.299249028 +0100
+++ asterisk/channels/chan_sip.c	2008-01-02 22:46:21.778148732 +0100
@@ -208,6 +208,7 @@
 };
 static struct ast_jb_conf global_jbconf;	/*!< Global jitterbuffer configuration */
 
+static int default_freq_ok = DEFAULT_FREQ_OK;
 static const char config[] = "sip.conf";	/*!< Main configuration file */
 static const char notify_config[] = "sip_notify.conf";	/*!< Configuration file for sending Notify with CLI commands to reconfigure or reboot phones */
 
@@ -1351,6 +1352,7 @@
 	int pokeexpire;			/*!<  When to expire poke (qualify= checking) */
 	int lastms;			/*!<  How long last response took (in ms), or -1 for no response */
 	int maxms;			/*!<  Max ms we will accept for the host to be up, 0 to not monitor */
+	int qualifyfreq;		/*!<  Qualification: How often to check for the host to be up */
 	struct timeval ps;		/*!<  Time for sending SIP OPTION in sip_pke_peer() */
 	struct sockaddr_in defaddr;	/*!<  Default IP address, used until registration */
 	struct ast_ha *ha;		/*!<  Access control list */
@@ -11648,6 +11650,7 @@
 		ast_cli(fd, "%s\n",status);
  		ast_cli(fd, "  Useragent    : %s\n", peer->useragent);
  		ast_cli(fd, "  Reg. Contact : %s\n", peer->fullcontact);
+		ast_cli(fd, "  Qualify Freq : %d seconds\n", peer->qualifyfreq/1000);
 		if (peer->chanvars) {
  			ast_cli(fd, "  Variables    :\n");
 			for (v = peer->chanvars ; v ; v = v->next)
@@ -11724,6 +11727,7 @@
 		astman_append(s, "%s\r\n", status);
  		astman_append(s, "SIP-Useragent: %s\r\n", peer->useragent);
  		astman_append(s, "Reg-Contact : %s\r\n", peer->fullcontact);
+		astman_append(s, "Qualify Freq : %d seconds\n", peer->qualifyfreq/1000);
 		if (peer->chanvars) {
 			for (v = peer->chanvars ; v ; v = v->next) {
  				astman_append(s, "ChanVariable:\n");
@@ -11969,6 +11973,7 @@
 		ast_cli(a->fd, "  SIP realtime:           Disabled\n" );
 	else
 		ast_cli(a->fd, "  SIP realtime:           Enabled\n" );
+	ast_cli(a->fd, "  Qualify Freq :          %d\n", default_freq_ok/1000);
 
 	ast_cli(a->fd, "\nNetwork Settings:\n");
 	ast_cli(a->fd, "---------------------------\n");
@@ -14010,7 +14015,7 @@
 
 	/* Try again eventually */
 	peer->pokeexpire = ast_sched_replace(peer->pokeexpire, sched,
-		is_reachable ? DEFAULT_FREQ_OK : DEFAULT_FREQ_NOTOK,
+		is_reachable ? peer->qualifyfreq : DEFAULT_FREQ_NOTOK,
 		sip_poke_peer_s, peer);
 }
 
@@ -18010,6 +18015,7 @@
 	/* If we have realm authentication information, remove them (reload) */
 	clear_realm_authentication(peer->auth);
 	peer->auth = NULL;
+	peer->qualifyfreq = default_freq_ok;
 
 	for (; v || ((v = alt) && !(alt=NULL)); v = v->next) {
 		if (handle_common_options(&peerflags[0], &mask[0], v))
@@ -18200,7 +18206,14 @@
 				ast_log(LOG_WARNING, "Qualification of peer '%s' should be 'yes', 'no', or a number of milliseconds at line %d of sip.conf\n", peer->name, v->lineno);
 				peer->maxms = 0;
 			}
-		} else if (!strcasecmp(v->name, "maxcallbitrate")) {
+		} else if (!strcasecmp(v->name, "qualifyfreq")) {
+			int i;
+			if (sscanf(v->value, "%d", &i) == 1)  {
+			peer->qualifyfreq = i * 1000;  } else {
+				ast_log(LOG_WARNING, "Invalid qualifyfreq number '%s' at line %d of %s\n",v->value, v->lineno, config);
+			}
+		}
+		else if (!strcasecmp(v->name, "maxcallbitrate")) {
 			peer->maxcallbitrate = atoi(v->value);
 			if (peer->maxcallbitrate < 0)
 				peer->maxcallbitrate = default_maxcallbitrate;
@@ -18363,6 +18376,7 @@
 	global_directrtpsetup = FALSE;		/* Experimental feature, disabled by default */
 	global_alwaysauthreject = 0;
 	global_allowsubscribe = FALSE;
+	default_freq_ok = DEFAULT_FREQ_OK;
 	snprintf(global_useragent, sizeof(global_useragent), "%s %s", DEFAULT_USERAGENT, ASTERISK_VERSION);
 	snprintf(global_sdpsession, sizeof(global_sdpsession), "%s %s", DEFAULT_SDPSESSION, ASTERISK_VERSION);
 	snprintf(global_sdpowner, sizeof(global_sdpowner), "%s", DEFAULT_SDPOWNER);
@@ -18680,7 +18694,15 @@
 				ast_log(LOG_WARNING, "Qualification default should be 'yes', 'no', or a number of milliseconds at line %d of sip.conf\n", v->lineno);
 				default_qualify = 0;
 			}
-		} else if (!strcasecmp(v->name, "callevents")) {
+		} else if (!strcasecmp(v->name, "qualifyfreq")) {
+			int i;
+			if (sscanf(v->value, "%d", &i) == 1) {
+			default_freq_ok = i * 1000;
+			} else {
+				ast_log(LOG_WARNING, "Invalid qualifyfreq number '%s' at line %d of %s\n", v->value, v->lineno, config);
+			}
+		}
+		 else if (!strcasecmp(v->name, "callevents")) {
 			global_callevents = ast_true(v->value);
 		} else if (!strcasecmp(v->name, "maxcallbitrate")) {
 			default_maxcallbitrate = atoi(v->value);
diff -ru asterisk-original/configs/sip.conf.sample asterisk/configs/sip.conf.sample
--- asterisk-original/configs/sip.conf.sample	2008-01-02 11:43:08.495202673 +0100
+++ asterisk/configs/sip.conf.sample	2008-01-02 15:46:29.600854295 +0100
@@ -101,6 +101,10 @@
 				; and subscriptions (seconds)
 ;minexpiry=60			; Minimum length of registrations/subscriptions (default 60)
 ;defaultexpiry=120		; Default length of incoming/outgoing registration
+;qualifyfreq=60                 ; Qualification: How often to check for the 
+                                ; host to be up in seconds
+                                ; Set to low value if you use low timeout for
+                                ; NAT of UDP sessions
 ;notifymimetype=text/plain	; Allow overriding of mime type in MWI NOTIFY
 ;buggymwi=no			; Cisco SIP firmware doesn't support the MWI RFC
 				; fully. Enable this option to not get error messages
@@ -812,6 +816,10 @@
 ;qualify=1000			; Consider it down if it's 1 second to reply
 				; Helps with NAT session
 				; qualify=yes uses default value
+;qualifyfreq=60			; Qualification: How often to check for the 
+				; host to be up in seconds
+				; Set to low value if you use low timeout for
+				; NAT of UDP sessions
 ;
 ; Call group and Pickup group should be in the range from 0 to 63
 ;