Multicasting Settings

Setting

Description

MulticastAddressRange The range of multicast addresses (host group addresses) to which RealServer can send a live multicast stream.
MulticastControlList The range of client or network addresses (typically on an intranet) which RealServer allows to receive multicast delivery.
MulticastDeliveryOnly Restricts the client addresses specified in MulticastControlList to multicast reception only-client addresses so restricted cannot connect to RealServer in unicast mode.
MulticastPort The port number for multicast broadcasts.
MulticastTTL The Time To Live (TTL) for multicast packets.

MulticastAddressRange

The range of multicast addresses (host group addresses) to which RealServer can send a live multicast stream. The network administrator will know which multicast addresses are available on the local intranet.

When starting a multicast delivery of a live broadcast, RealServer scans the address range specified in MulticastAddressRange for the first available address. RealServer sends the live broadcast to the first available multicast address that it finds within the range.

Be sure to include enough addresses in MulticastAddressRange to accommodate your broadcasting needs. If you are running only one RealServer process (see MaxThreads setting on page 70), you need one multicast address for each live multicast broadcast. For example, if you are broadcasting three live programs by multicast, you need at least three addresses in the MulticastAddressRange. If you are running more than one RealServer process, you should make available one multicast address for each broadcast times the number of forks used by RealServer. For example, if you are broadcasting three live programs via multicast, and RealServer is using three forks, you need at least nine multicast addresses.

Multicast addresses can range from 224.0.0.0 to 239.244.255.255. The addresses between 224.0.0.0 and 224.0.0.255 are reserved for routing protocols and other protocols. Other addresses and ranges are reserved for other applications. See RFC 1700, "Assigned Numbers," for a complete list of restricted addresses. In general, if the multicast address does not start with the decimal numbers 244, it should be usable. MulticastAddressRange is required for multicast support.
Default value (none)
Range of values Valid IP addresses in the range
224.0.0.0 - 239.255.255.255

Syntax

MulticastAddressRange <address>-<address>

where:

<address> is an IP address configured for multicast delivery.

Example

MulticastAddressRange 230.125.141.0-230.125.141.255

MulticastControlList

The range of client or network addresses (typically on an intranet) which RealServer allows to receive multicast delivery. RealServer gives a client whose address is within the range access to multicast delivery only when the client requests such delivery.

This MulticastControList is required for multicast support.
Default value (none)
Range of values Valid IP addresses

Syntax

MulticastControlList [{<address>, <net mask>}, ...]

where:

<address> is the domain address of the client computer or network for which RealServer uses multicast delivery if requested by the player.

<net mask> is a mask that specifies the bits in the domain address that are treated as wildcards. The bits in the IP address that correspond with the zeros in the net mask are treated as wildcards. For example, an address of 121.23.101.0 with a net mask of 255.255.255.0 accepts all IP addresses from 121.23.101.0 to 121.23.101.255. If the net mask is 255.255.255.128, all IP addresses from 121.23.101.0 to 121.23.101.127 are accepted.

If you want to grant multicast access to all addresses within a domain, you can specify a net mask of 0.0.0.0 if you have a RealServer licensed for the Internet. If you have an intranet-only RealServer, you cannot specify a net mask of 0.0.0.0.

To prevent all Players from accessing multicast delivery, do not include a MulticastControlList value in your configuration file.

The net mask 255.255.255.255 accepts only the single IP address specified in the address.

Example

MulticastControlList [{204.71.154.0, 255.255.255.0}]

 

MulticastDeliveryOnly

When set to True, restricts the client addresses specified in MulticastControlList to multicast reception only-client addresses so restricted cannot connect to RealServer in unicast mode. This option can be used to help control bandwidth on a network (typically on an intranet).

MulticastDeliveryOnly does not affect client addresses that are not in the MulticastControlList-such addresses can connect to RealServer in unicast mode.

This MulticastDeliveryOnly setting is optional for multicast support.
Default value False
Range of values True, False

Syntax

MulticastDeliveryOnly <value>

where:

<value> is True to restrict client addresses in the MulticastControlList to multicast reception only, or False to allow any type of reception.

Example

MulticastDeliveryOnly True

 

MulticastPort

The port number for multicast broadcasts. The MulticastPort setting is optional for multicast support. Note that MulticastPort and PNAPort have different purposes. The multicast port is the port to which RealServer sends live multicast broadcasts. The PNA port is the port that a Player uses to establish a TCP/IP control connection with RealServer.
Default value 7070
Range of values Any valid port number

Syntax

MulticastPort <value>

where:

<value> is the port number for multicast broadcasts.

Example

MulticastPort 7075

MulticastTTL

The Time To Live (TTL) for multicast packets. This value is used by routers in your network to determine whether a multicast packet is allowed to pass through the router. The MulticastTTL setting is optional for multicast support.
Default value 16
Range of values 0 - 255

Syntax

MulticastTTL <value>

where:

<value> is the TTL value included in multicast packet headers.

The following are the typical TTL values and their meanings:

TTL Value

Keep Packets Within

0 or 1 Local host
16 Site
63 Region
129-255 World

For most multicast uses, you should keep the multicast packets within your intranet by setting MulticastTTL to 16 or less.

See your network administrator for information on how your network is configured.

Example

MulticastTTL 16

© 1997 RealNetworks, Inc.