The BIG-IP Link Controller is a dedicated IP Application Switch that manages bi-directional traffic to a site across multiple links, regardless of connection type or provider. The Link Controller provides granular traffic control for Internet gateways, so that users can define how traffic is distributed across their links in a way that meets their business priorities. The Link Controller transparently monitors the availability and health of links to optimally direct traffic across the best available link.
The Link Controller includes the following features:
Link load balancing is defined as managing traffic across multiple Internet or WAN gateways. Link load balancing ensures high availability in the network, and improves the performance of a web site or data center. Link load balancing provides a method by which an organization can reliably manage a multi-homed network. A multi-homed network is composed of one or more data centers that have more than one gateway, or link, to the Internet.
As enterprises increase their reliance on the Internet for delivering mission-critical applications and services, using only one link and ISP provider to access the public network represents a single point of failure. Link Load balancing, with the BIG-IP Link Controller, removes the risk of this single point of failure by enabling enterprises to control and monitor multiple links for their Internet connectivity.
The BIG-IP Link Controller:
With the Link Controller, you can manage both inbound and outbound traffic over multiple links. You can distribute traffic based on performance, bandwidth cost, and bandwidth availability. The metrics you can specify are the limits on bandwidth usage, and the pricing structure of your purchased bandwidth. When you specify the limits and pricing metrics for your links, the Link Controller then load balances the links based on those metrics.
You can monitor several aspects of your managed links using the following tools:
The following features and enhancements are part of the version 4.5 release.
In version 4.5, the Configuration utility now includes screens designed for quick and simple link configuration. You can use the screens for your initial setup, and to later refine your configuration using the advanced properties screens. For more information on working with the new link configuration screens, see Chapter 16, Working with Link Configuration, in the BIG-IP Reference Guide.
With this version of the BIG-IP Link Controller, you can configure full duplex billing support if that is the billing method that your Internet service providers (ISPs) use. When you enable full duplex billing support, the Link Controller manages and reports on the link traffic based on the peak usage of ingress or egress bandwidth, whichever is higher. If duplex billing is not enabled, the controller manages and reports on link traffic based on the combined total of ingress and egress bandwidth usage. For more information, see Chapter 16, Working with Link Configuration , in the BIG-IP Reference Guide.
You can now use the Setup utility to configure a remote LDAP or RADIUS authentication server. With this feature, you no longer need to directly edit configuration files to set up your LDAP or RADIUS authentication server.
Also, this release of the BIG-IP Link Controller expands the number of user roles that you can assign to user accounts for the purpose of user authorization. In addition to the standard Full Read/Write, Partial Read/Write, and Read-Only access levels, you can now define which user interface an administrator uses to access the BIG-IP system (the Configuration utility, the command line interface, or the iControl interface). These user authorization roles are stored in the local LDAP database on the BIG-IP system and are designed to operate in concert with centralized LDAP and RADIUS authentication.
For details on the Setup utility features, see Chapter 2, Using the Setup Utility, in the BIG-IP Reference Guide. For details on the new user accounts, see Chapter 17, Administering the BIG-IP System , in the BIG-IP Reference Guide.
The Link Statistics screens now include a Billing Estimate screen, where you can enter date ranges and view your actual link bandwidth usage compared to your purchased bandwidth. For details on the Billing Estimate screen, review the online help for that screen. To view the Billing Estimate screen, from the navigation pane, expand the Link Statistics item, and then click P95.
With this release, the BIG-IP system now offers a centralized Setup screen to set the passwords for the three system accounts: root, admin, and support. For the support account, you can also specify whether to allow command line access, Web access, or both.
For more information on managing system accounts, see Chapter 17, Administering the BIG-IP System , in the BIG-IP Reference Guide.