RealAudio and Firewalls

# Release Notes: RealAudio and Firewalls

This documentation explains how to set up and use RealAudio in conjunction with firewalls as well as directions for using the provided code to set up a firewall proxy. The software and documentation are provided to you in accordance with your license agreement.

## About RealAudio 2.0 and Firewalls

Progressive Networks has enhanced RealAudio to support firewalls. Users can receive real-time on-demand audio from the Internet without exposing their company's network to security risks.

- What is a firewall?
- What are the RealAudio firewall solutions?
- How do I get the latest information about RealAudio and firewalls?

## What is a firewall?

Firewalls are security devices used to protect companies from unauthorized access to their servers. Many companies use firewalls to control access to their networks and proprietary information. The firewall's role is to ensure that all communication between an organization's network and the Internet conform to the organization's security policies.

Many companies and organizations have connected their local area networks, wide area networks, and the Internet together in what is commonly referred to as a global area network. While extremely beneficial in terms of communication and access to information, this interconnectivity can expose a company's network and mission critical information to unauthorized entry and access. The firewall is used to prevent unauthorized accesses.

### How do firewalls work?

Firewalls use two methods of securing transmission to and from internal networks: proxy services (also known as application-level gateways) and packet filtering.

#### Proxy Services

With proxy services, the firewall first determines if a requested connection between a computer on the internal network and one on the outside is permitted. If the connection is authorized, the firewall, acting as an intermediary, sets up the necessary communication links between the two computers. As an intermediary, the firewall can monitor the communication between the two networks and suppress any unauthorized activity.

#### Packet Filtering

Packet filtering uses a single, unified packet-filtering engine, through which all network traffic is processed and then either forwarded or blocked based on a set of logical rules defined by a firewall administrator. Many organizations use a combination of packet filtering and proxy firewalls to achieve a higher level of security.

## What are the RealAudio Firewall Solutions?

### Third-Party Vendor Solutions

Working in conjunction with third-party firewall vendors, version 2.0 of the RealAudio Player allows Internet users behind proxy server firewalls to receive RealAudio. These firewalls are able to identify RealAudio files and direct them in a secure manner to requesters located on internal networks. The list of firewall vendors who support RealAudio continues to grow. If your firewall vendor is not listed, ask your firewall representative to contact us about joining our firewall developers program.

### RealAudio Firewall Proxy Kit

For companies using either a proprietary or public domain firewall, Progressive Networks provides a firewall proxy kit containing sample code and specifications for building their own proxy service.

### New Configurations for Packet-filtering Firewalls

Companies with packet filter firewalls can take advantage of RealAudio by reconfiguring their firewalls. Progressive Networks has produced documentation to help firewall administrators configure packet filter firewalls to support RealAudio.

The RealAudio Player 2.0 comes with two configuration options that limit the port numbers allowed. These options reduce the configurational changes required on the firewall.

Continue to Configuring the RealAudio Player for Firewalls

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