Load Balancing Features; Load Balancing Elements; Real Server; Real Server Group (Rsg) - Avaya P333R-LB User Manual

Chapter 1 Overview

Load Balancing Features

Load Balancing technology allows network managers to control the amount of
network traffic to various firewalls and servers, as well as to redirect traffic to
internal addresses. By distributing traffic to different firewalls or servers, Load
Balancing improves response time. Load Balancing also performs health checks on
the firewalls or servers to make sure that they are functioning at a minimum level. If
a firewall or server is not functional, the Load Balancing application directs traffic to
other available firewalls or servers. Load Balancing provides increased fault
tolerance, and, as an alternative to deploying larger servers, scalability.
Load Balancing implements a sophisticated mechanism for Real Server Metrics
Selection, Real Server Health Checking, and Persistency.

Load Balancing Elements

There are four conceptual Load Balancing elements:
•

Real Server.

• Real Server Group.
•

Virtual Service.

•

Virtual Server.

Real Server
A Real Server is a physical server that is associated with a Real IP address. One or
more Real Servers may belong to a Real Server Group.

Real Server Group (RSG)

A Real Server Group is a logical grouping of Real Servers used for load balancing.
For example, for Server Load Balancing, the load balancer distributes packets to
Real Servers belonging to a specific RSG.
Virtual Service
Virtual Services are abstract links to RSGs provided by a Virtual Server. For
example, load-balanced forwarding of HTTP or FTP packets is a Virtual Service.
Virtual Server
A Virtual Server represents the server to the outside world. It is associated with a
Virtual IP and provides Virtual Services. For example, a load balancer that
intercepts traffic from the WAN acts as a Virtual Server.
12 Avaya P333R-LB User's Guide