# Chapter 1: New Features

The Helix™ Universal Server version 9.0 architecture facilitates extensibility and interoperability with third-party solutions. This chapter describes new features in Helix Universal Server, and covers upgrade issues from previous versions of RealSystem Server.

# New Features in Helix Universal Server 9.0

The latest version of Helix Universal Server introduces the following features.

## Aliasing

Aliases are substitutions for actual file names and directory paths used in URLs. Using an alias, the Helix Universal Server administrator can mask actual resources in published URLs, as well as shorten and simplify published URLs. For more information, see "Setting Up Aliases".

## Content Caching

Content caching enables two or more Helix Universal Servers to transfer prerecorded media files dynamically, providing two key benefits. First, caching improves playback quality by propagating the content closer to the viewer. Second, it reduces delivery cost by caching content at the network's edge. For more information, see "Content Caching".

## Custom Logging

Custom logging is a flexible system for generating reports. It is based on templates that define what information should be captured, when and how often it should be captured, and how it should be delivered. You can use default templates or create your own templates. For more information, see Chapter 17.

## SLTA

SLTA is RealNetworks' next-generation tool for streaming a prerecorded clip as a live event. SLTA streams more media formats than its predecessor, G2SLTA. It provides a more robust way of delivering streams, acting as a transmitter that splits a stream to a Helix Universal Server receiver. For more information, see Chapter 10.

## RTSP Cache Directives

By default, a proxy may cache or split all on-demand content and live broadcasts hosted on Helix Universal Server. You may not want this in some cases, though. The RTSP cache directives feature gives you full control to define directives for on-demand content and live broadcasts that prohibit proxy devices from caching or splitting streaming media. For more information, see "Restricting Proxies from Caching or Splitting Content".

## Redundant Servers

This feature enables you to add a level of redundancy to content delivery. By default, RealOne Player attempts to reconnect to the originating Helix Universal Server if the RTSP connection breaks. However, you can specify an alternate server that RealOne Player contacts instead. For more information see, "Implementing Redundant Servers".

## Windows Media Streaming

Helix Universal Server can stream the Windows Media format to Windows Media Player using either MMS (Microsoft Media Services protocol) or HTTP. It can also connect to Windows Media Encoder through HTTP, allowing you to transmit (split) a Windows Media broadcast to other Helix Universal Servers. Thus, you can have a homogeneous streaming network that delivers multiple file formats, including RealMedia, Windows Media, and QuickTime.

## MPEG Streaming

Helix Universal Server delivers MPEG-1, MPEG-2, MP3, and MPEG-4 content. For details, see "MPEG Audio and Video".

## SureStream Splitting

Helix Universal Server helps you conserve bandwidth when splitting a live RealAudio or RealVideo broadcast. With splitting, you typically send multiple bit rate streams from the transmitter to the receiver, regardless of whether clients using the stream require each of the different bit rates. With SureStream-aware splitting, only the bit rates requested by the client are actually sent over the network to the receiver. For more information, see "SureStream-Aware Splitting".

## RealOne Player Statistics

The new client statistics type 4 gather playback information specifically for RealOne Player, including packet and bandwidth information for each stream, as well as the results of using TurboPlay. For more information, see "Statistics Type 4".

# Features Introduced in Version 8

This section describes the features that were added in RealSystem Server version 8, and are included in Helix Universal Server version 9.0.

## Distributed Licensing

This feature enables a set of Helix Universal Servers within an organization to use the same license file. It allows you to configure features independently on individual Helix Universal Servers while sharing a pool of connections. For more information, see "Distributing Server Licenses".

## Port Hinting

For clients that can receive Helix Universal Server content only through "HTTP cloaking," you can create URLs that list the server ports to try. This way, the client doesn't waste time by trying to discern the correct port to use. For more information, see "Handling Communication through Nonstandard Ports".

## Redundant Encoders

You can now use parallel sources as input for Helix Universal Server. Should one stream become unavailable, Helix Universal Server automatically switches all users to the next available stream. For more information, see "Using Broadcast Redundancy".

## Splitting

The redesigned splitting feature provides greater scalability and reliability. Most notably, multicasting between transmitter and receiver is now possible. If you've used splitting in earlier versions of RealSystem Server, see "Upgrades from RealServer 7 or Earlier" for more information.

## Support for QuickTime and Additional Data Types

Helix Universal Server 8 (and 9) support even more data types than before, such as MPEG Audio (MP3) and Macromedia Flash version 4. QuickTime version 4 and higher files can be streamed to Apple's QuickTime 4 and higher player.

# Upgrade Issues

The following sections explain issues with upgrading to Helix Universal Server from an earlier version of RealSystem Server.

## Compatibility with Version 8

There are no known compatibility issues between Helix Universal Server and RealSystem Server version 8. This means that you can use a version 8 configuration file with Helix Universal Server. In this case, no features new in Helix Universal Server are enabled, but no existing feature are disabled. This allows you to migrate to a new version by installing the new version, using your old configuration file, and activating new features on an as-needed basis.

| Tip: RealNetworks recommends using identical versions of server products for server-to-server feature like splitting.

## Upgrades from RealServer 7 or Earlier

Helix Universal Server is fully compatible with RealServer 3 through 7, with the exception of the splitting feature. Because of the many changes to the splitting feature from version 8, all nodes along the stream—transmitter, relay, and receiver—must run Helix Universal Server. If you are moving from a RealServer 7 or earlier product, note that links used for splitting have completely changed. Keep in mind that a source is now called a transmitter, and a splitter is now called a receiver.

| For More Information: See "Linking to Split Content".

## Default Installation Directory

On Windows, Helix Universal Server installs into the following default location, which differs from the installation paths for previous versions of RealSystem Server:

    C:\Program Files\Real\Helix Server

If you choose the default location, you'll need to move your existing content to the new directory tree, as described in "Upgrading in a Different Directory".

## Legacy Bandwidth Negotiation

Before the introduction of SureStream RealAudio and RealVideo, bandwidth negotiation was handled by creating one file for each available bandwidth, and placing all of the files in a directory that ended with `.rm`. Files were named according to the compression algorithm used to encode them. If you have upgraded from an earlier version of RealSystem server that used the older style of bandwidth negotiation, your new Helix Universal Server still reads the old directory structure and can perform the bandwidth negotiation automatically.

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