Allow to specify UDPv4/6 multicast interface

[paraslash.git] / ggo / server.m4

diff --git a/ggo/server.m4 b/ggo/server.m4
index 30c3b41a45919715ca495c80697fb618d16f0068..8aa753b90953ec4aa1df4cb24ea2857a6fe87c4c 100644 (file)
--- a/ggo/server.m4
+++ b/ggo/server.m4
@@ -271,6 +271,12 @@ int typestr="port"
 default="8000"
 optional
 
+option "udp_mcast_iface" -
+#~~~~~~~~~~~~~~~~~~~~~~~~~~
+"outgoing udp multicast interface"
+string
+optional
+
 option "udp_header_interval" H
 #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 "duration for sending header"
@@ -292,11 +298,19 @@ option "udp_ttl" t
 #~~~~~~~~~~~~~~~~~
 "set time to live value"
 int typestr="num"
-default="10"
+default="-1"
 optional
 details="
-       This option instructs the udp sender to set the time to live to
-       \"num\" for the sending udp socket. Only useful for multicast
-       udp streaming.
+       This option applies exclusively to multicast UDPv4/v6 streaming.
+
+       For the sending UDPv4 socket it sets the multicast Time-To-Live
+       value to \"num\".  Traditional TTL scope values are: 0=host,
+       1=network, 32=same site, 64=same region, 128=same continent,
+       255=unrestricted. Please note however that this scoping is not
+       a good solution: RFC 2365 e.g. presents a better alternative.
+
+       When using UDPv6 multicasting, the option sets the number of
+       multicast hops (as described in RFC 3493); a value of -1
+       allows the kernel to auto-select the hop value.
 "
 </qu>