PDF of this tutorialEnterprise Caching is a unique method of increasing network performance and throughput. Enterprise Caching is also a revolutionary concept for improving network efficiency. It offers enterprises, Internet service providers (ISP), and application service providers a comprehensive, enterprise-application focused solution that provides significant improvement in handling data from diverse applications and protocols. Independent testing has shown that Enterprise Caching can boost data throughput by more than 400% at T1/E1 speeds. See test results at http://www.tolly.com, "Tolly Up to Spec."
Enterprise Caching provides optimization for today's packet-based networks, transferring a variety of packets and protocols. Enterprise Caching is also future-proof, since it will accelerate future applications due to the nature of its patented technologies. These technologies include selective caching, vertical data analysis (VDA), adaptive packet compression, and others.
The following diagram shows how Enterprise Caching is applied at the frame level.
Figure 2. Enterprise Caching Illustrated
(Click on image for full-size version.)
Selective Caching
Selective caching is an advanced algorithm that identifies data that is worth caching and stores it for later retrieval. "Data," as defined by selective caching, may be full objects (such as an entire graphics interface format [GIF] file) or a partial object (such as a color palette of a GIF file), common JavaScript code that appears in hypertext markup language (HTML) pages, a bitmap that is being repeatedly sent by the Citrix ICA protocol (for example, several users running Microsoft Word over Citrix Winframe), etc. It is not limited to a specific protocol.
Once selective caching identifies data that is worth caching, it will store a copy of it for later usage. If that data is met again, only a reference to the data will be sent rather than the data itself. Selective caching is effective with the following:
- Internet Traffic: If multiple users are accessing the same site, many parts of the site will be cached.
- Intranet Traffic: Most users are accessing the same content.
- Extranet Traffic: B2B, CGI, ASP, XML, Web applications, etc.
- E-mail and Collaboration Tools: MS Exchange, Lotus Notes, simple mail transfer protocol (SMTP) e-mail
- Citrix Winframe and MetaFram XP
- Structured Query Language (SQL): Microsoft SQL, Oracle, IBM, etc.
- ERP Systems: SAP, Peoplesoft, JD Edwards, BAAN, etc.
- CRM Systems: Oracle, Siebel, E.piphany, etc.
- Web Casting: Audio/video broadcasts and all other enterprise traffic
Vertical Data Analysis
VDA dynamically identifies different protocol segments in a packet. Generally, each segment relates to a different part in the protocol stack. For example, VDA may separate a packet into the following sections:
| GIF File |
| HTTP/1.1 Header |
| XML |
| HTTP/1.1 Header |
| TCP |
| IP |
| Cisco HDLC |
The separation into different segments is done in a "semi-dynamic" manner—VDA is programmed with basic rules and with the understanding of some protocols. Using this preprogrammed adaptive understanding, it parses packets into their different segments. Consequently, "header style" information in each packet is reduced significantly. Examples of "header style" information are sequence numbers, checksums, protocol identifiers, etc.
Adaptive Packet Compression
Adaptive packet compression is used in conjunction with VDA and selective caching to compress data that is not cached or that was not handled by VDA. Different data types are assigned different compression algorithms. For example each of the following types of data will be handled in a different manner:
- HTML
- SQL
- JavaScript
By applying a different compression strategy on each of these types of data, better results can be achieved compared to legacy compression.
