diff --git a/doc/CHANGES-staging/res_fax_negotiate_both b/doc/CHANGES-staging/res_fax_negotiate_both
new file mode 100644
index 0000000000..73be756028
--- /dev/null
+++ b/doc/CHANGES-staging/res_fax_negotiate_both
@@ -0,0 +1,7 @@
+Subject: res_fax
+
+Added configuration option "negotiate_both". This option is only used
+when a gateway is enabled, and a v21 preamble is detected. If this option
+is enabled, once a preamble is detected Asterisk will initiate negotiation
+requests to both T.38 enabled endpoint versus waiting, and forwarding a
+request from an initiating endpoint. Defaults to disabled.
diff --git a/include/asterisk/res_fax.h b/include/asterisk/res_fax.h
index c1dd37847c..dc455bbfd4 100644
--- a/include/asterisk/res_fax.h
+++ b/include/asterisk/res_fax.h
@@ -189,6 +189,9 @@ struct ast_fax_session_details {
int faxdetect_flags;
/*! Non-zero if T.38 is negotiated */
int is_t38_negotiated;
+ /*! Upon v21 detection the gateway sends negotiation requests to both
+ T.38 endpoints, and do not wait on the "other" side to initiate */
+ int negotiate_both;
};
struct ast_fax_tech;
diff --git a/res/res_fax.c b/res/res_fax.c
index 7d9cb4e8ca..ebb2b46266 100644
--- a/res/res_fax.c
+++ b/res/res_fax.c
@@ -226,6 +226,9 @@
R/W The timeout used for T.38 negotiation.
+
+ R/W Upon v21 detection allow gateway to send negotiation requests to both T.38 endpoints, and do not wait on the "other" side to initiate (yes|no)
+
@@ -722,6 +725,7 @@ static struct ast_fax_session_details *session_details_new(void)
d->gateway_id = -1;
d->faxdetect_id = -1;
d->gateway_timeout = 0;
+ d->negotiate_both = 0;
return d;
}
@@ -3023,6 +3027,22 @@ static struct ast_frame *fax_gateway_detect_v21(struct fax_gateway *gateway, str
enum ast_t38_state state_other;
enum ast_t38_state state_active;
struct ast_frame *fp;
+ struct ast_fax_session_details *details;
+ int negotiate_both = 0;
+
+ /*
+ * The default behavior is to wait for the active endpoint to initiate negotiation.
+ * Find out if this has been overridden. If so, instead of waiting have Asterisk
+ * initiate the negotiation requests out to both endpoints.
+ */
+ details = find_or_create_details(active);
+ if (details) {
+ negotiate_both = details->negotiate_both;
+ ao2_ref(details, -1);
+ } else {
+ ast_log(LOG_WARNING, "Detect v21 - no session details for channel '%s'\n",
+ ast_channel_name(chan));
+ }
destroy_v21_sessions(gateway);
@@ -3039,7 +3059,7 @@ static struct ast_frame *fax_gateway_detect_v21(struct fax_gateway *gateway, str
}
/* May be called endpoint is improperly configured to rely on the calling endpoint
* to initiate T.38 re-INVITEs, send T.38 negotiation request to called endpoint */
- if (state_active == T38_STATE_UNKNOWN) {
+ if (negotiate_both && state_active == T38_STATE_UNKNOWN) {
ast_debug(1, "sending T.38 negotiation request to %s\n", ast_channel_name(active));
if (active == chan) {
ast_channel_unlock(chan);
@@ -4557,6 +4577,8 @@ static int acf_faxopt_read(struct ast_channel *chan, const char *cmd, char *data
ast_fax_modem_to_str(details->modems, buf, len);
} else if (!strcasecmp(data, "t38timeout")) {
snprintf(buf, len, "%u", details->t38timeout);
+ } else if (!strcasecmp(data, "negotiate_both")) {
+ ast_copy_string(buf, details->negotiate_both != -1 ? "yes" : "no", len);
} else {
ast_log(LOG_WARNING, "channel '%s' can't read FAXOPT(%s) because it is unhandled!\n", ast_channel_name(chan), data);
res = -1;
@@ -4695,6 +4717,8 @@ static int acf_faxopt_write(struct ast_channel *chan, const char *cmd, char *dat
}
} else if ((!strcasecmp(data, "modem")) || (!strcasecmp(data, "modems"))) {
update_modem_bits(&details->modems, value);
+ } else if (!strcasecmp(data, "negotiate_both")) {
+ details->negotiate_both = ast_true(ast_skip_blanks(value));
} else {
ast_log(LOG_WARNING, "channel '%s' set FAXOPT(%s) to '%s' is unhandled!\n", ast_channel_name(chan), data, value);
res = -1;