mgcp: Optionally send ptime in SDP
Currently the SDP 'ptime' media attribute is never set in generated
MGCP responses.
This patch optionally includes the 'ptime' attribute if
packet_duration_ms is != 0. This behaviour can be enabled/disabled
by using the VTY command "sdp audio-payload send-ptime" (enabled by
default).
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/libmgcp/mgcp_protocol.c b/openbsc/src/libmgcp/mgcp_protocol.c
index b8d1920..7d3ad74 100644
--- a/openbsc/src/libmgcp/mgcp_protocol.c
+++ b/openbsc/src/libmgcp/mgcp_protocol.c
@@ -230,11 +230,12 @@
const char *addr = endp->cfg->local_ip;
const char *fmtp_extra = endp->bts_end.fmtp_extra;
char sdp_record[4096];
+ int len;
if (!addr)
addr = endp->cfg->source_addr;
- snprintf(sdp_record, sizeof(sdp_record) - 1,
+ len = snprintf(sdp_record, sizeof(sdp_record) - 1,
"I: %u\n\n"
"v=0\r\n"
"o=- %u 23 IN IP4 %s\r\n"
@@ -247,7 +248,25 @@
endp->net_end.local_port, endp->bts_end.payload_type,
endp->bts_end.payload_type, endp->tcfg->audio_name,
fmtp_extra ? fmtp_extra : "", fmtp_extra ? "\r\n" : "");
+
+ if (len < 0 || len >= sizeof(sdp_record))
+ goto buffer_too_small;
+
+ if (endp->bts_end.packet_duration_ms > 0 && endp->tcfg->audio_send_ptime) {
+ int nchars = snprintf(sdp_record + len, sizeof(sdp_record) - len,
+ "a=ptime:%d\r\n",
+ endp->bts_end.packet_duration_ms);
+ if (nchars < 0 || nchars >= sizeof(sdp_record) - len)
+ goto buffer_too_small;
+
+ len += nchars;
+ }
return create_resp(endp, 200, " OK", msg, trans_id, NULL, sdp_record);
+
+buffer_too_small:
+ LOGP(DMGCP, LOGL_ERROR, "SDP buffer too small: %d (needed %d)\n",
+ sizeof(sdp_record), len);
+ return NULL;
}
/*
@@ -1109,6 +1128,7 @@
cfg->trunk.trunk_type = MGCP_TRUNK_VIRTUAL;
cfg->trunk.audio_name = talloc_strdup(cfg, "AMR/8000");
cfg->trunk.audio_payload = 126;
+ cfg->trunk.audio_send_ptime = 1;
cfg->trunk.omit_rtcp = 0;
INIT_LLIST_HEAD(&cfg->trunks);
@@ -1131,6 +1151,7 @@
trunk->trunk_nr = nr;
trunk->audio_name = talloc_strdup(cfg, "AMR/8000");
trunk->audio_payload = 126;
+ trunk->audio_send_ptime = 1;
trunk->number_endpoints = 33;
trunk->omit_rtcp = 0;
llist_add_tail(&trunk->entry, &cfg->trunks);
diff --git a/openbsc/src/libmgcp/mgcp_vty.c b/openbsc/src/libmgcp/mgcp_vty.c
index e48b050..235b8bd 100644
--- a/openbsc/src/libmgcp/mgcp_vty.c
+++ b/openbsc/src/libmgcp/mgcp_vty.c
@@ -105,6 +105,8 @@
if (g_cfg->trunk.audio_fmtp_extra)
vty_out(vty, " sdp audio fmtp-extra %s%s",
g_cfg->trunk.audio_fmtp_extra, VTY_NEWLINE);
+ vty_out(vty, " %ssdp audio-payload send-ptime%s",
+ g_cfg->trunk.audio_send_ptime ? "" : "no ", VTY_NEWLINE);
vty_out(vty, " loop %u%s", !!g_cfg->trunk.audio_loop, VTY_NEWLINE);
vty_out(vty, " number endpoints %u%s", g_cfg->trunk.number_endpoints - 1, VTY_NEWLINE);
if (g_cfg->call_agent_addr)
@@ -391,6 +393,26 @@
"sdp audio payload name NAME",
SDP_STR AUDIO_STR AUDIO_STR "Name\n" "Payload name\n")
+DEFUN(cfg_mgcp_sdp_payload_send_ptime,
+ cfg_mgcp_sdp_payload_send_ptime_cmd,
+ "sdp audio-payload send-ptime",
+ SDP_STR AUDIO_STR
+ "Send SDP ptime (packet duration) attribute\n")
+{
+ g_cfg->trunk.audio_send_ptime = 1;
+ return CMD_SUCCESS;
+}
+
+DEFUN(cfg_mgcp_no_sdp_payload_send_ptime,
+ cfg_mgcp_no_sdp_payload_send_ptime_cmd,
+ "no sdp audio-payload send-ptime",
+ NO_STR SDP_STR AUDIO_STR
+ "Send SDP ptime (packet duration) attribute\n")
+{
+ g_cfg->trunk.audio_send_ptime = 0;
+ return CMD_SUCCESS;
+}
+
DEFUN(cfg_mgcp_loop,
cfg_mgcp_loop_cmd,
"loop (0|1)",
@@ -568,6 +590,8 @@
trunk->audio_payload, VTY_NEWLINE);
vty_out(vty, " sdp audio-payload name %s%s",
trunk->audio_name, VTY_NEWLINE);
+ vty_out(vty, " %ssdp audio-payload send-ptime%s",
+ trunk->audio_send_ptime ? "" : "no ", VTY_NEWLINE);
vty_out(vty, " loop %d%s",
trunk->audio_loop, VTY_NEWLINE);
if (trunk->omit_rtcp)
@@ -649,6 +673,28 @@
return CMD_SUCCESS;
}
+DEFUN(cfg_trunk_sdp_payload_send_ptime,
+ cfg_trunk_sdp_payload_send_ptime_cmd,
+ "sdp audio-payload send-ptime",
+ SDP_STR AUDIO_STR
+ "Send SDP ptime (packet duration) attribute\n")
+{
+ struct mgcp_trunk_config *trunk = vty->index;
+ trunk->audio_send_ptime = 1;
+ return CMD_SUCCESS;
+}
+
+DEFUN(cfg_trunk_no_sdp_payload_send_ptime,
+ cfg_trunk_no_sdp_payload_send_ptime_cmd,
+ "no sdp audio-payload send-ptime",
+ NO_STR SDP_STR AUDIO_STR
+ "Send SDP ptime (packet duration) attribute\n")
+{
+ struct mgcp_trunk_config *trunk = vty->index;
+ trunk->audio_send_ptime = 0;
+ return CMD_SUCCESS;
+}
+
DEFUN(cfg_trunk_omit_rtcp,
cfg_trunk_omit_rtcp_cmd,
"rtcp-omit",
@@ -966,6 +1012,8 @@
install_element(MGCP_NODE, &cfg_mgcp_no_patch_rtp_ts_cmd);
install_element(MGCP_NODE, &cfg_mgcp_no_patch_rtp_cmd);
install_element(MGCP_NODE, &cfg_mgcp_sdp_fmtp_extra_cmd);
+ install_element(MGCP_NODE, &cfg_mgcp_sdp_payload_send_ptime_cmd);
+ install_element(MGCP_NODE, &cfg_mgcp_no_sdp_payload_send_ptime_cmd);
install_element(MGCP_NODE, &cfg_mgcp_trunk_cmd);
install_node(&trunk_node, config_write_trunk);
@@ -983,6 +1031,8 @@
install_element(TRUNK_NODE, &cfg_trunk_no_patch_rtp_ts_cmd);
install_element(TRUNK_NODE, &cfg_trunk_no_patch_rtp_cmd);
install_element(TRUNK_NODE, &cfg_trunk_sdp_fmtp_extra_cmd);
+ install_element(TRUNK_NODE, &cfg_trunk_sdp_payload_send_ptime_cmd);
+ install_element(TRUNK_NODE, &cfg_trunk_no_sdp_payload_send_ptime_cmd);
return 0;
}