Bandwidth Management Basics

Bandwidth Management Basics

Learning the lexicon of bandwidth management will take some time. But here are some of the basics to help you sort through what can be confusing terms tossed about by vendor marketing departments.

Application Acceleration ― Often employed as part of a WAN Optimization effort, Application Acceleration is comprised of several techniques, namely compression, caching and protocol optimization, to speed up performance of applications on a wide area network.

Application Bonding ― For Internet-facing applications, this technique makes proxy connections for multiple queries, receives the replies, and reassembles and delivers them to the end user. The advantage is being able to use links from multiple providers at multiple sizes and speeds. The disadvantage is only Web and ftp downloads can be “bonded.” Otherwise the traffic will be blocked by ISPs as spoofing.

Bandwidth Aggregation ― See Link Aggregation

Bandwidth Bonding ― Combining multiple carrier links and multiple link speeds and capacities by sending packets across them as if they were one larger pipe. Bonding requires like appliances on both ends of the connection.

Bandwidth Limiting ― See Traffic Shaping

Bandwidth Shaping ― See Traffic Shaping

Bandwidth Throttling ― See Traffic Shaping

Broadband Bonding ― See Bandwidth Bonding

Caching ― One of the data reduction techniques used in Application Acceleration is caching. Object caching is placing a copy of the content in a location closer to the user than the originating server. This saves time and bandwidth when a user requests the same object again or when multiple users request an object at the same time. A second, more granular type is byte caching, which is made possible by two appliances on the local and remote ends of the network. Accordingly, byte caching is bidirectional.

Channel Bonding ― See Bandwidth Bonding

Compression ― One of the data reduction techniques used in Application Acceleration, compression technology reduces the number of packets that are sent by removing extraneous or redundant from the data flow. When the data arrives at the other end, the same algorithm uncompresses the data. Not all applications are equally compressible. While e-mail and ftp compress well, encrypted traffic and VoIP do not.

Content Filtering ― Another component that can fall under WAN Optimization is eliminating undesirable content that can clog up the WAN and impact the performance. Examples include Web surfing, peer-to-peer, file sharing, personal VoIP calling traffic. Every corporation should set acceptable use policies for network users; however content filtering techniques can help that along.

Load Balancing ― A technology used in Multi-Homed Networks to distribute traffic evenly across multiple WAN links. It also enables Link Failover.

Link Aggregation ― Used to describe both Load Balancing and Bandwidth Bonding techniques

Link Balancing ― See Load Balancing

Link Bonding ― See Bandwidth Bonding

Link Failover ― A benefit of Load Balancing in Multi-Homed Networks is that when one WAN links fails, traffic can be routed to the remaining link(s).

Link Redundancy ― See Link Failover

Multi-homed Networks ― Having several WAN connections to a single ISP or to multiple ISPs

Multi-WAN ― See Multi-homed Networks

Multi-WAN Router ― A device that performs Load Balancing in Multi-homed Networks

Protocol Optimization ― One of the techniques used in Application Acceleration, protocol optimization makes chatty protocols — CIFS or file sharing — work better and faster by reducing the number of roundtrips between the client and server.

Quality of Service ― A mechanism employed in WAN Optimization for regulating network bandwidth by defining requirements for certain users or applications in terms of throughput, priority, latency and packet loss

Rate Limiting ― See Traffic Shaping

Route Optimization ― A technology used in a Multi-Homed Networks that monitors available external links in real time and routes packets based on performance metrics

Traffic Shaping ― A technology used in WAN Optimization that limits bandwidth by user or by an application. Bandwidth can be throttled based on IP address, MAC address, network subnet or service type

WAFS ― See Wide Area File Service

Wide Area File Service ― A data reduction technique that employs caching of file copies accessed over a WAN in local devices, so that subsequent users get accelerated performance

WAN Optimization ― A set of techniques, such as Traffic Shaping, QoS and Data Reduction, that are used to improve the performance of the WAN

Source: Khali Henderson 02/03/2009
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