chan_dahdi: Add inband_on_proceeding compatibility option.

The new inband_on_proceeding option causes Asterisk to 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
progress indicator ie informing the CPE side to attach to the B channel
for audio.  However, some non-compliant ISDN switches send a PROCEEDING
without the progress indicator ie indicating inband audio is available and
assume that the CPE device has connected the media path for listening to
ringback and other messages.

ASTERISK-17834 which causes this issue was dealing with a non-compliant
network switch.

(closes issue ASTERISK-21151)
Reported by: Gianluca Merlo
Tested by: rmudgett
........

Merged revisions 384685 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 384689 from http://svn.asterisk.org/svn/asterisk/branches/11

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@384696 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/channels/chan_dahdi.c b/channels/chan_dahdi.c
index 277cdaa457f30c0e0333450b8575f3d2629fb3b0..bd58b6d87b444e587ed89fbbb097d3c8ed7d48f2 100644 (file)
--- a/channels/chan_dahdi.c
+++ b/channels/chan_dahdi.c
@@ -1413,6 +1413,7 @@ 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_proceeding = 1,
 
 #if defined(HAVE_PRI_CCSS)
                        .cc_ptmp_recall_mode = 1,/* specificRecall */
@@ -12951,6 +12952,7 @@ 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_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));
 #if defined(HAVE_PRI_MWI)
@@ -18218,6 +18220,8 @@ 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_proceeding")) {
+                               confp->pri.pri.inband_on_proceeding = ast_true(v->value);
 #if defined(HAVE_PRI_DISPLAY_TEXT)
                        } else if (!strcasecmp(v->name, "display_send")) {
                                confp->pri.pri.display_flags_send = dahdi_display_text_option(v->value);

diff --git a/channels/sig_pri.c b/channels/sig_pri.c
index dba005214e37613e4bea64b0f201c968172fd9f1..353b7f39b298e01a8c77d90e350966ec1be46198 100644 (file)
--- a/channels/sig_pri.c
+++ b/channels/sig_pri.c
@@ -6752,9 +6752,11 @@ static void *pri_dchannel(void *vpri)
                                        /* Bring voice path up */
                                        pri_queue_control(pri, chanpos, AST_CONTROL_PROGRESS);
                                        pri->pvts[chanpos]->progress = 1;
+                                       sig_pri_set_dialing(pri->pvts[chanpos], 0);
                                        sig_pri_open_media(pri->pvts[chanpos]);
+                               } else if (pri->inband_on_proceeding) {
+                                       sig_pri_set_dialing(pri->pvts[chanpos], 0);
                                }
-                               sig_pri_set_dialing(pri->pvts[chanpos], 0);
                                sig_pri_unlock_private(pri->pvts[chanpos]);
                                break;
                        case PRI_EVENT_FACILITY:

diff --git a/channels/sig_pri.h b/channels/sig_pri.h
index db052862de2d153416c295475135e5eedcfa6dae..805ed9b486a1b8b6565589a0aaad4c65597c41b5 100644 (file)
--- a/channels/sig_pri.h
+++ b/channels/sig_pri.h
@@ -470,6 +470,8 @@ struct sig_pri_span {
         * appended to the initial_user_tag[].
         */
        unsigned int append_msn_to_user_tag:1;
+       /*! TRUE if a PROCEEDING message needs to unsquelch the received audio. */
+       unsigned int inband_on_proceeding:1;
 #if defined(HAVE_PRI_MCID)
        /*! \brief TRUE if allow sending MCID request on this span. */
        unsigned int mcid_send:1;

diff --git a/configs/chan_dahdi.conf.sample b/configs/chan_dahdi.conf.sample
index 85ffd6d616a316578316f28f4bb37e30e921e149..7d64cf3831bdcbd7f5ab329bc954844866391989 100644 (file)
--- a/configs/chan_dahdi.conf.sample
+++ b/configs/chan_dahdi.conf.sample
@@ -196,6 +196,18 @@ context=public
 ;
 ;resetinterval = 3600
 ;
+; 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
+; progress indicator ie informing the CPE side to attach to the B channel
+; for audio.  However, some non-compliant ISDN switches send a PROCEEDING
+; without the progress indicator ie indicating inband audio is available and
+; assume that the CPE device has connected the media path for listening to
+; ringback and other messages.
+; Default yes in current release branches for backward compatibility.
+;
+;inband_on_proceeding=yes
+;
 ; Overlap dialing mode (sending overlap digits)
 ; Cannot be changed on a reload.
 ;