diff --git a/UPGRADE.txt b/UPGRADE.txt
index 2a4c1ded44..f79f048b34 100644
--- a/UPGRADE.txt
+++ b/UPGRADE.txt
@@ -20,7 +20,7 @@
 ===
 ===========================================================
 
-from 11.10.0 to 11.11.0
+from 11.10.2 to 11.11.0
  - Added a compatibility option for chan_sip, 'websocket_write_timeout'.
    When a websocket connection exists where Asterisk writes a substantial
    amount of data to the connected client, and the connected client is slow
@@ -41,6 +41,10 @@ from 11.10.0 to 11.11.0
    hash to be specified for the DTLS fingerprint placed in SDP. Supported
    values are 'sha-1' and 'sha-256' with 'sha-256' being the default.
 
+ - Added the inband_on_setup_ack compatibility option to chan_dahdi.conf to
+   deal with switches that don't send an inband progress indication in the
+   SETUP ACKNOWLEDGE message.
+
 from 11.10.0 to 11.10.1
  - MixMonitor AMI actions now require users to have authorization classes.
    * MixMonitor - system
diff --git a/channels/chan_dahdi.c b/channels/chan_dahdi.c
index 3a37087d9d..5610b00443 100644
--- a/channels/chan_dahdi.c
+++ b/channels/chan_dahdi.c
@@ -1409,6 +1409,7 @@ static struct dahdi_chan_conf dahdi_chan_conf_default(void)
 			.localdialplan = PRI_NATIONAL_ISDN + 1,
 			.nodetype = PRI_CPE,
 			.qsigchannelmapping = DAHDI_CHAN_MAPPING_PHYSICAL,
+			.inband_on_setup_ack = 1,
 			.inband_on_proceeding = 1,
 
 #if defined(HAVE_PRI_CCSS)
@@ -12960,6 +12961,7 @@ static struct dahdi_pvt *mkintf(int channel, const struct dahdi_chan_conf *conf,
 							pris[span].pri.layer1_ignored = 0;
 						}
 						pris[span].pri.append_msn_to_user_tag = conf->pri.pri.append_msn_to_user_tag;
+						pris[span].pri.inband_on_setup_ack = conf->pri.pri.inband_on_setup_ack;
 						pris[span].pri.inband_on_proceeding = conf->pri.pri.inband_on_proceeding;
 						ast_copy_string(pris[span].pri.initial_user_tag, conf->chan.cid_tag, sizeof(pris[span].pri.initial_user_tag));
 						ast_copy_string(pris[span].pri.msn_list, conf->pri.pri.msn_list, sizeof(pris[span].pri.msn_list));
@@ -18334,6 +18336,8 @@ static int process_dahdi(struct dahdi_chan_conf *confp, const char *cat, struct
 #endif	/* defined(HAVE_PRI_MWI) */
 			} else if (!strcasecmp(v->name, "append_msn_to_cid_tag")) {
 				confp->pri.pri.append_msn_to_user_tag = ast_true(v->value);
+			} else if (!strcasecmp(v->name, "inband_on_setup_ack")) {
+				confp->pri.pri.inband_on_setup_ack = ast_true(v->value);
 			} else if (!strcasecmp(v->name, "inband_on_proceeding")) {
 				confp->pri.pri.inband_on_proceeding = ast_true(v->value);
 #if defined(HAVE_PRI_DISPLAY_TEXT)
diff --git a/channels/sig_pri.c b/channels/sig_pri.c
index 1d9067adf8..3e231f6249 100644
--- a/channels/sig_pri.c
+++ b/channels/sig_pri.c
@@ -1516,6 +1516,9 @@ static int pri_fixup_principle(struct sig_pri_span *pri, int principle, q931_cal
 #if defined(HAVE_PRI_CALL_WAITING)
 		new_chan->is_call_waiting = old_chan->is_call_waiting;
 #endif	/* defined(HAVE_PRI_CALL_WAITING) */
+#if defined(HAVE_PRI_SETUP_ACK_INBAND)
+		new_chan->no_dialed_digits = old_chan->no_dialed_digits;
+#endif	/* defined(HAVE_PRI_SETUP_ACK_INBAND) */
 
 #if defined(HAVE_PRI_AOC_EVENTS)
 		old_chan->aoc_s_request_invoke_id_valid = 0;
@@ -1531,6 +1534,9 @@ static int pri_fixup_principle(struct sig_pri_span *pri, int principle, q931_cal
 #if defined(HAVE_PRI_CALL_WAITING)
 		old_chan->is_call_waiting = 0;
 #endif	/* defined(HAVE_PRI_CALL_WAITING) */
+#if defined(HAVE_PRI_SETUP_ACK_INBAND)
+		old_chan->no_dialed_digits = 0;
+#endif	/* defined(HAVE_PRI_SETUP_ACK_INBAND) */
 
 		/* More stuff to transfer to the new channel. */
 		new_chan->call_level = old_chan->call_level;
@@ -7363,8 +7369,19 @@ static void *pri_dchannel(void *vpri)
 					 * We explicitly DO NOT want to check PRI_PROG_CALL_NOT_E2E_ISDN
 					 * because it will mess up ISDN to SIP interoperability for
 					 * the ALERTING message.
+					 *
+					 * Q.931 Section 5.1.3 says that in scenarios with overlap
+					 * dialing where no called digits are received and the tone
+					 * option requires dialtone, the switch MAY send an inband
+					 * progress indication ie to indicate dialtone presence in
+					 * the SETUP ACKNOWLEDGE.  Therefore, if we did not send any
+					 * digits with the SETUP then we must assume that dialtone
+					 * is present and open the voice path.  Fortunately when
+					 * interoperating with SIP, we should be sending digits.
 					 */
-					&& (e->setup_ack.progressmask & PRI_PROG_INBAND_AVAILABLE)
+					&& ((e->setup_ack.progressmask & PRI_PROG_INBAND_AVAILABLE)
+						|| pri->inband_on_setup_ack
+						|| pri->pvts[chanpos]->no_dialed_digits)
 #endif	/* defined(HAVE_PRI_SETUP_ACK_INBAND) */
 					) {
 					/*
@@ -7977,7 +7994,12 @@ int sig_pri_call(struct sig_pri_chan *p, struct ast_channel *ast, const char *rd
 	if (!keypad || !ast_strlen_zero(c + p->stripmsd + dp_strip))
 #endif	/* defined(HAVE_PRI_SETUP_KEYPAD) */
 	{
-		pri_sr_set_called(sr, c + p->stripmsd + dp_strip, pridialplan, s ? 1 : 0);
+		char *called = c + p->stripmsd + dp_strip;
+
+		pri_sr_set_called(sr, called, pridialplan, s ? 1 : 0);
+#if defined(HAVE_PRI_SETUP_ACK_INBAND)
+		p->no_dialed_digits = !called[0];
+#endif	/* defined(HAVE_PRI_SETUP_ACK_INBAND) */
 	}
 
 #if defined(HAVE_PRI_SUBADDR)
diff --git a/channels/sig_pri.h b/channels/sig_pri.h
index 43acb12697..e9a699ffff 100644
--- a/channels/sig_pri.h
+++ b/channels/sig_pri.h
@@ -343,6 +343,10 @@ struct sig_pri_chan {
 	/*! \brief TRUE if this is a call waiting call */
 	unsigned int is_call_waiting:1;
 #endif	/* defined(HAVE_PRI_CALL_WAITING) */
+#if defined(HAVE_PRI_SETUP_ACK_INBAND)
+	/*! TRUE if outgoing SETUP had no called digits */
+	unsigned int no_dialed_digits:1;
+#endif	/* defined(HAVE_PRI_SETUP_ACK_INBAND) */
 
 	struct ast_channel *owner;
 
@@ -470,6 +474,8 @@ struct sig_pri_span {
 	 * appended to the initial_user_tag[].
 	 */
 	unsigned int append_msn_to_user_tag:1;
+	/*! TRUE if a SETUP ACK message needs to open the audio path. */
+	unsigned int inband_on_setup_ack:1;
 	/*! TRUE if a PROCEEDING message needs to unsquelch the received audio. */
 	unsigned int inband_on_proceeding:1;
 #if defined(HAVE_PRI_MCID)
diff --git a/configs/chan_dahdi.conf.sample b/configs/chan_dahdi.conf.sample
index be9381624a..dfd6e5280d 100644
--- a/configs/chan_dahdi.conf.sample
+++ b/configs/chan_dahdi.conf.sample
@@ -196,6 +196,23 @@ context=public
 ;
 ;resetinterval = 3600
 ;
+; Assume inband audio may be present when a SETUP ACK message is received.
+; Q.931 Section 5.1.3 says that in scenarios with overlap dialing, when a
+; dialtone is sent from the network side, progress indicator 8 "Inband info
+; now available" MAY be sent to the CPE if no digits were received with
+; the SETUP.  It is thus implied that the ie is mandatory if digits came
+; with the SETUP and dialtone is needed.
+; This option should be enabled, when the network sends dialtone and you
+; want to hear it, but the network doesn't send the progress indicator when
+; needed.
+;
+; NOTE: For Q.SIG setups this option should be enabled when outgoing overlap
+; dialing is also enabled because Q.SIG does not send the progress indicator
+; with the SETUP ACK.
+; Default yes in current release branches for backward compatibility.
+;
+;inband_on_setup_ack=yes
+;
 ; Assume inband audio may be present when a PROCEEDING message is received.
 ; Q.931 Section 5.1.2 says the network cannot assume that the CPE side has
 ; attached to the B channel at this time without explicitly sending the