From d3c310a28c801d4d64d4d1763c9c53f6f18a2388 Mon Sep 17 00:00:00 2001 From: Richard Mudgett <rmudgett@digium.com> Date: Wed, 29 Apr 2015 14:29:10 -0500 Subject: [PATCH] chan_dahdi: Add the chan_dahdi.conf force_restart_unavailable_chans option. Some telco switches occasionally ignore ISDN RESTART requests. The fix for ASTERISK-19608 added an escape clause for B channels in the restarting state if the telco ignores a RESTART request. If the telco fails to acknowledge the RESTART then Asterisk will assume the telco acknowledged the RESTART on the second call attempt requesting the B channel by the telco. The escape clause is good for dealing with RESTART requests in general but it does cause the next call for the restarting B channel to be rejected if the telco insists the call must go on that B channel. chan_dahdi doesn't really need to issue a RESTART request in response to receiving a cause 44 (Requested channel not available) code. Sending the RESTART in such a situation is not required (nor prohibited) by the standards. I think chan_dahdi does this for historical reasons to deal with buggy peers to get channels unstuck in a similar fashion as the chan_dahdi.conf resetinterval option. * Add the chan_dahdi.conf force_restart_unavailable_chans compatability option that when disabled will prevent chan_dahdi from trying to RESTART the channel in response to a cause 44 code. ASTERISK-25034 #close Reported by: Richard Mudgett Change-Id: Ib8b17a438799920f4a2038826ff99a1884042f65 --- UPGRADE.txt | 7 +++++++ channels/chan_dahdi.c | 4 ++++ channels/sig_pri.c | 15 ++------------- channels/sig_pri.h | 2 ++ configs/samples/chan_dahdi.conf.sample | 14 ++++++++++++++ 5 files changed, 29 insertions(+), 13 deletions(-) diff --git a/UPGRADE.txt b/UPGRADE.txt index d0db4dbcad..9adf3052c2 100644 --- a/UPGRADE.txt +++ b/UPGRADE.txt @@ -40,6 +40,13 @@ CLI: by the CLI command is always the Asterisk version. This CLI command will be removed in Asterisk 14. +chan_dahdi: + - Added the force_restart_unavailable_chans compatibility option. When + enabled it causes Asterisk to restart the ISDN B channel if an outgoing + call receives cause 44 (Requested channel not available). The new option + is enabled by default in current release branches for backward + compatibility. + res_pjsip: - The dtmf_mode now supports a new option, 'auto'. This mode will attempt to detect if the device supports RFC4733 DTMF. If so, it will choose that diff --git a/channels/chan_dahdi.c b/channels/chan_dahdi.c index 53899d8699..6958e5be54 100644 --- a/channels/chan_dahdi.c +++ b/channels/chan_dahdi.c @@ -919,6 +919,7 @@ static struct dahdi_chan_conf dahdi_chan_conf_default(void) .privateprefix = "", .unknownprefix = "", .colp_send = SIG_PRI_COLP_UPDATE, + .force_restart_unavailable_chans = 1, .resetinterval = -1, }, #endif @@ -12346,6 +12347,7 @@ static struct dahdi_pvt *mkintf(int channel, const struct dahdi_chan_conf *conf, #if defined(HAVE_PRI_MCID) pris[span].pri.mcid_send = conf->pri.pri.mcid_send; #endif /* defined(HAVE_PRI_MCID) */ + pris[span].pri.force_restart_unavailable_chans = conf->pri.pri.force_restart_unavailable_chans; #if defined(HAVE_PRI_DATETIME_SEND) pris[span].pri.datetime_send = conf->pri.pri.datetime_send; #endif /* defined(HAVE_PRI_DATETIME_SEND) */ @@ -18258,6 +18260,8 @@ static int process_dahdi(struct dahdi_chan_conf *confp, const char *cat, struct else ast_log(LOG_WARNING, "'%s' is not a valid reset interval, should be >= 60 seconds or 'never' at line %d.\n", v->value, v->lineno); + } else if (!strcasecmp(v->name, "force_restart_unavailable_chans")) { + confp->pri.pri.force_restart_unavailable_chans = ast_true(v->value); } else if (!strcasecmp(v->name, "minunused")) { confp->pri.pri.minunused = atoi(v->value); } else if (!strcasecmp(v->name, "minidle")) { diff --git a/channels/sig_pri.c b/channels/sig_pri.c index 395ae354ce..a66d16b536 100644 --- a/channels/sig_pri.c +++ b/channels/sig_pri.c @@ -133,15 +133,6 @@ */ //#define ALWAYS_PICK_CHANNEL 1 -/*! - * Define to force a RESTART on a channel that returns a cause - * code of PRI_CAUSE_REQUESTED_CHAN_UNAVAIL(44). If the cause - * is because of a stuck channel on the peer and the channel is - * always the next channel we pick for an outgoing call then - * this can help. - */ -#define FORCE_RESTART_UNAVAIL_CHANS 1 - #if defined(HAVE_PRI_CCSS) struct sig_pri_cc_agent_prv { /*! Asterisk span D channel control structure. */ @@ -7170,9 +7161,9 @@ static void *pri_dchannel(void *vpri) pri_hangup(pri->pri, pri->pvts[chanpos]->call, e->hangup.cause); pri->pvts[chanpos]->call = NULL; } -#if defined(FORCE_RESTART_UNAVAIL_CHANS) if (e->hangup.cause == PRI_CAUSE_REQUESTED_CHAN_UNAVAIL && pri->sig != SIG_BRI_PTMP && !pri->resetting + && pri->force_restart_unavailable_chans && pri->pvts[chanpos]->resetting == SIG_PRI_RESET_IDLE) { ast_verb(3, "Span %d: Forcing restart of channel %d/%d since channel reported in use\n", @@ -7181,7 +7172,6 @@ static void *pri_dchannel(void *vpri) pri->pvts[chanpos]->resetting = SIG_PRI_RESET_ACTIVE; pri_reset(pri->pri, PVT_TO_CHANNEL(pri->pvts[chanpos])); } -#endif /* defined(FORCE_RESTART_UNAVAIL_CHANS) */ if (e->hangup.aoc_units > -1) ast_verb(3, "Channel %d/%d, span %d received AOC-E charging %d unit%s\n", pri->pvts[chanpos]->logicalspan, pri->pvts[chanpos]->prioffset, pri->span, (int)e->hangup.aoc_units, (e->hangup.aoc_units == 1) ? "" : "s"); @@ -7319,9 +7309,9 @@ static void *pri_dchannel(void *vpri) pri_hangup(pri->pri, pri->pvts[chanpos]->call, e->hangup.cause); pri->pvts[chanpos]->call = NULL; } -#if defined(FORCE_RESTART_UNAVAIL_CHANS) if (e->hangup.cause == PRI_CAUSE_REQUESTED_CHAN_UNAVAIL && pri->sig != SIG_BRI_PTMP && !pri->resetting + && pri->force_restart_unavailable_chans && pri->pvts[chanpos]->resetting == SIG_PRI_RESET_IDLE) { ast_verb(3, "Span %d: Forcing restart of channel %d/%d since channel reported in use\n", @@ -7330,7 +7320,6 @@ static void *pri_dchannel(void *vpri) pri->pvts[chanpos]->resetting = SIG_PRI_RESET_ACTIVE; pri_reset(pri->pri, PVT_TO_CHANNEL(pri->pvts[chanpos])); } -#endif /* defined(FORCE_RESTART_UNAVAIL_CHANS) */ #ifdef SUPPORT_USERUSER if (!ast_strlen_zero(e->hangup.useruserinfo)) { diff --git a/channels/sig_pri.h b/channels/sig_pri.h index 12f3dcae70..52e6c729db 100644 --- a/channels/sig_pri.h +++ b/channels/sig_pri.h @@ -496,6 +496,8 @@ struct sig_pri_span { #if defined(HAVE_PRI_MCID) /*! \brief TRUE if allow sending MCID request on this span. */ unsigned int mcid_send:1; + /*! \brief TRUE if forcing RESTART when receive cause 44 on this span. */ + unsigned int force_restart_unavailable_chans:1; #endif /* defined(HAVE_PRI_MCID) */ #if defined(HAVE_PRI_DATETIME_SEND) /*! \brief Configured date/time ie send policy option. */ diff --git a/configs/samples/chan_dahdi.conf.sample b/configs/samples/chan_dahdi.conf.sample index 13691fcdf2..e027e64fac 100644 --- a/configs/samples/chan_dahdi.conf.sample +++ b/configs/samples/chan_dahdi.conf.sample @@ -196,6 +196,20 @@ context=public ; ;resetinterval = 3600 ; +; Enable per span to force a RESTART on a channel that returns a cause +; code of PRI_CAUSE_REQUESTED_CHAN_UNAVAIL(44). If the cause is because +; of a stuck channel on the peer and the channel is always the next +; channel we pick for an outgoing call then this might help. +; +; NOTE: Sending a RESTART in response to a cause 44 is not required +; (nor prohibited) by the standards and is likely a primitive chan_dahdi +; response to call collisions (glare) and buggy peers. However, there +; are telco switches out there that ignore the RESTART and continue to +; send calls to the channel in the restarting state. +; Default yes in current release branches for backward compatibility. +; +;force_restart_unavailable_chans=yes +; ; 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 -- GitLab