diff --git a/CHANGES b/CHANGES
index 728f8bc0b9896f25859d64f7bcb8a527d89fabe6..18236d62b97c869d6fcf0ebd9f5b5c5f35b48397 100644
--- a/CHANGES
+++ b/CHANGES
@@ -19,6 +19,7 @@ Zaptel channel driver (chan_zap) Changes
 ----------------------------------------
  * Channels can now be configured using named sections in zapata.conf, just
    like other channel drivers, including the use of templates.
+ * The default for pridialplan has changed from 'national' to 'unknown'.
 
 PBX Changes
 -----------
diff --git a/channels/chan_zap.c b/channels/chan_zap.c
index fcc8e1546b31506539802a4c0ed395cd2dec0a09..89059c6a60038b05d149931f7365863f31558cc6 100644
--- a/channels/chan_zap.c
+++ b/channels/chan_zap.c
@@ -750,7 +750,7 @@ static struct zt_chan_conf zt_chan_conf_default(void) {
 		.pri = {
 			.nsf = PRI_NSF_NONE,
 			.switchtype = PRI_SWITCH_NI2,
-			.dialplan = PRI_NATIONAL_ISDN + 1,
+			.dialplan = PRI_UNKNOWN + 1,
 			.localdialplan = PRI_NATIONAL_ISDN + 1,
 			.nodetype = PRI_CPE,
 
diff --git a/configs/zapata.conf.sample b/configs/zapata.conf.sample
index 20bcdb8b03d3f13e423720b88e3a9b2a9173cb03..8ddb7a517033f6a1bf80f407f40f04008bb7949f 100644
--- a/configs/zapata.conf.sample
+++ b/configs/zapata.conf.sample
@@ -79,10 +79,20 @@
 ;
 ;nsf=none
 ;
-; PRI Dialplan:  Only RARELY used for PRI.
+; PRI Dialplan: The ISDN-level Type Of Number (TON) or numbering plan, used for
+; the dialed number.  For most installations, leaving this as 'unknown' (the
+; default) works in the most cases.  In some very unusual circumstances, you
+; may need to set this to 'dynamic' or 'redundant'.  Note that if you set one
+; of the others, you will be unable to dial another class of numbers.  For
+; example, if you set 'national', you will be unable to dial local or
+; international numbers.
+;
 ; PRI Local Dialplan:  Only RARELY used for PRI (sets the calling number's 
-; numbering plan)
-; pridialplan and prilocaldialplan cannot be changed on a reload.
+; numbering plan).  In North America, the typical use is sending the 10 digit
+; callerID number and setting the prilocaldialplan to 'national' (the default).
+; Only VERY rarely will you need to change this.
+;
+; Neither pridialplan nor prilocaldialplan can be changed on reload.
 ;
 ; unknown:        Unknown
 ; private:        Private ISDN
@@ -93,7 +103,7 @@
 ; redundant:      Same as dynamic, except that the underlying number is not 
 ;                 changed (not common)
 ;
-;pridialplan=national
+;pridialplan=unknown
 ;prilocaldialplan=national
 ; 
 ; pridialplan may be also set at dialtime, by prefixing the dialled number with