Chapter 4: Redundant Proxies

The Helix Universal Proxy alternates feature provides another level of redundancy for delivering streaming media content. By default, when an RTSP connection between RealOne Player and Helix Universal Proxy becomes unavailable, the customer is unable to access the content until RealOne Player is able to reestablish the connection to the Helix Universal Proxy. However, if you've designated alternates for the unavailable Helix Universal Proxy, the client also attempts to connect to one of the alternate proxies for delivery of the stream.

Backward Compatibility

The RealOne Player reconnect feature is supported for earlier versions of Helix Universal Proxy, but use of ProxyAlternates is only available in Helix^™ Universal Proxy version 9.0 and later.

Dependencies

The redundant proxy feature is an alternate delivery option for Helix Universal Proxy, providing real-time failover protection. It has no dependencies on any other lists or variables in the proxy configuration file.

Samples

The following example demonstrates how to specify three alternates for a Helix Universal Proxy version 9.

<!-- R E D U N D A N T   P R O X Y -->
<LIST Name="ProxyAlternates">
     <LIST Name="Alternates">
          <LIST Name="Alternate_1">
               <VAR Host="172.31.255.254"/>
               <VAR Port="554"/>
          </LIST>
          <LIST Name="Alternate_2">
               <VAR Host="main.rbn.com"/>
               <VAR Port="554"/>
          </LIST>
          <LIST Name="Alternate_3">
               <VAR Host="home.rbn.com"/>
               <VAR Port="554"/>
          </LIST>
     </LIST>
</LIST>

Alternate Proxies

Alternate proxies for a Helix Universal Proxy are specified via XML variables in the ProxyAlternates list within the configuration file, rmproxy.cfg. The variables supply the hostname and port of each alternate proxy. A Helix Universal Proxy can have any number of alternate proxies.

As a rule, alternates should be comparable to the primary Helix Universal Proxy:

Alternate proxies must have access to the same Helix Universal Servers as the primary Helix Universal Proxy.

This allows alternates access to exactly the same content—whether live broadcasts or on-demand content—as the primary Helix Universal Proxy for which they are designated alternates.

Alternates should have a similar configuration to the primary Helix Universal Proxy.

For example, access control rules of an alternate should be similar to those of the primary proxy, to allow the same client access.

LIST: ProxyAlternates

This is the primary list tag that is used to identify the presence of alternate proxies in the configuration file.

<LIST Name="ProxyAlternates">
     ...list of designated alternate proxies...
</LIST>

Registry Value

config.ProxyAlternates

Example

<LIST Name="ProxyAlternates"> ... </LIST>

LIST: Alternates

The Alternates list contains a list of alternate proxies, where each alternate is itself a list.

<LIST Name="ProxyAlternates">
     <LIST Name="Alternates">
          ...designated alternate proxy lists...
     </LIST>
</LIST>

Registry Value

config.ProxyAlternates.Alternates

Example

<LIST Name="Alternates"> ... </LIST>

LIST: Alternate Name

This LIST defines a Helix Universal Proxy alternate. Specify any name for the list, as long as it is unique. When a Helix Universal Proxy becomes unavailable, RealOne Player attempts to connect to any designated alternate proxy in the list, beginning with the first alternate.

<LIST Name="ProxyAlternates">
     <LIST Name="Alternates">
          <LIST Name="Alternate Name">
               ...variables that define the alternate proxy...
          </LIST>
          ...other designated alternate proxy lists...
     </LIST>
</LIST>

Registry Value

config.ProxyAlternates.Alternates.string

Example

<LIST Name="Alternate_1"> ... </LIST>

VAR: Host

This variable specifies the hostname of the designated alternate proxy.

Tag Syntax

<VAR Dest="Destination"/>

Possible Values

Name - DNS hostname of the alternate proxy

###.###.###.### - IP address of the alternate proxy

Example

<VAR Dest="205.23.5.108"/>

VAR: Port

This variable specifies the RTSP port number through which to connect to the designated alternate proxy.

Tag Syntax

<VAR Port="integer"/>

Possible Values

554 - default data channel for RTSP connections

Example

<VAR Port="554"/>

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