Compression, Downgrade Behavior | Blue Coat Systems SGOS 4.x

Blue Coat SGOS 4.x Upgrade Guide

Upgrade Behavior

As BWM is a new feature, upgrade issues are restricted to previously existing bandwidth configuration that will now be subsumed into the BWM configuration.

BWM does not replace the older bandwidth limiting features currently available in Streaming (max streaming, max Real and max MMS). It complements it.

BWM replaces the bandwidth-limiting configuration in Access Logging. Related BWM classes are automatically created based on the older Access Log bandwidth configuration and placed under the class "access-log-logname,” where logname is the name of the log.

Downgrade Behavior

If downgraded, the access log behaves as previously configured.

Documentation References

Chapter 10, “Bandwidth Management,” in the Blue Coat ProxySG Configuration and Management Guide.

Compression

In SGOS 4.x, Blue Coat offers both HTTP compression and SOCKS compress.

•HTTP Compression is an algorithm that reduces a file size but does not lose any data. When you use compression depends upon three resources: server-side bandwidth, client-side bandwidth, and ProxySG CPU. If server-side bandwidth is more expensive in your environment than CPU, then you should always request compressed content from the origin content server (OCS). However, if CPU is comparatively expensive, the ProxySG should instead be configured to ask the OCS for the same HTTP compressions that the client asked for and to forward whatever the server returns.

The default configuration assumes that CPU is costlier than bandwidth. If this is not the case, you can change the ProxySG behavior.

•SOCKS compression is supported for TCP/IP tunnels, which can compress the data transferred between the branch (downstream proxy) and main office (upstream proxy), reducing bandwidth consumption and improving latency.

When SOCKS compression is used in conjunction with the new Blue Coat Endpoint Mapper (EPMapper) proxy, the Endpoint Mapper proxy accelerates Microsoft RPC traffic (applications that use dynamic port numbers) between branch and main offices, automatically creating TCP tunnels to ports where RPC services are running.

Upgrade Behavior

Prior to SGOS 4.x, the HTTP proxy did not cache objects if the server sent compressed content. With HTTP compression and variant object support, objects are now cached regardless of its encoding (if all other conditions allows caching).

With variant object support, multiple copies of the same object (variants) might exist in the cache, and that might affect object carrying capacity of the disk.

On-box compression and decompression can significantly affect CPU and RAM usage. This will directly affect the capacity of the box.

SGOS 4.x specifications

Blue Coat Systems SGOS 4.x is a robust operating system designed for the Blue Coat ProxySG series of appliances, which serve as content filtering and web security solutions. The SGOS (Secure Gateway Operating System) is crafted to enhance network performance while providing extensive security and policy enforcement capabilities. This article delves into the numerous features, technologies, and characteristics that define SGOS 4.x, making it an essential tool for organizations looking to fortify their web traffic management and security.

One of the standout features of SGOS 4.x is its advanced web filtering capabilities. The system employs a comprehensive URL categorization database that allows organizations to enforce content policies effectively. By categorizing millions of web pages, SGOS enables users to block or allow access to specific sites based on their content category, ensuring a safe browsing experience for employees and preventing access to harmful or non-work-related content.

Another notable technological characteristic of SGOS 4.x is its accelerated SSL decryption. As encrypted traffic continues to dominate the web, it becomes increasingly important for organizations to inspect this traffic for potential threats. SGOS 4.x offers robust SSL decryption capabilities that allow organizations to analyze encrypted traffic while maintaining the confidentiality and integrity of the data being transmitted. This attribute not only strengthens security but also aids in compliance with regulatory requirements.

SGOS 4.x is also equipped with exceptional caching and content delivery features. By caching frequently accessed content, the system reduces load times and optimizes bandwidth usage. This caching mechanism is enhanced by predefined policies that dictate how content is stored and retrieved, significantly improving user experience while reducing operational costs.

Furthermore, SGOS 4.x supports advanced reporting and analytics features. The integrated reporting tools provide administrators with insights into web usage patterns, bandwidth consumption, and security incidents. These insights facilitate informed decision-making and allow organizations to refine their web usage policies based on actual user behavior and threat landscape analysis.

In terms of scalability, SGOS 4.x is engineered to support a wide range of deployment scenarios, from small businesses to large enterprises. The architecture is designed to efficiently handle varying volumes of traffic without compromising performance or security, making it a flexible solution for diverse organizational needs.

Overall, Blue Coat Systems SGOS 4.x presents a powerful platform for web security and traffic management. With its advanced filtering, SSL decryption, caching, and analytics capabilities, SGOS 4.x remains a vital solution for organizations aiming to enhance their security posture and improve operational efficiency in an increasingly complex web environment.