Have Your Layer Cake and Eat It Too

by Tony Bourke, author of Server Load Balancing

Long ago, in the world of networking, network devices had specific purposes in a given infrastructure. Different devices, each performing a separate function, worked harmoniously in a well-oiled network machine. A set of well-established players in each genre (firewalls, routers, switches) made easy the system administrator's job of deciding which products would best serve his or her network installation. However, that has all changed.

Today there is a growing trend toward incorporating functions that would typically be handled by several separate devices into a single device. This trend is forever changing a once-familiar landscape, and many old-school vendors are waking to find new competition has sprouted up overnight. For system administrators, the added competition means they're faced with learning about many new and unfamiliar products.

So what's a system administrator to do? Stick with the tried-and-true method of every device having a single (or limited) set of functions? Or blow the entire budget on a new wundermachine, capable of performing all the network functions you need? The answer is probably somewhere in between, but as with any network planning and implementation, it depends on the type of site you have or on your organization's specific requirements.

The Grass Is Always Greener

Related Reading

Server Load Balancing
By Tony Bourke

Vendors, reeling from the drastic downturn in IT spending, are looking for ways to expand their current revenues while also taking market share from their competitors. In the realm of networking products, vendors have figured out that by adding a few features to an already existing product, they can easily attract more customers. What's more, the cost of developing new features can be relatively minor compared with developing a from-the-drawing-board product. This is because the former usually involves simply adding new code and loading it into an existing platform (or developing a blade for an already-existing chassis platform). The relatively low cost, when combined with the creation of a new, feature-rich product, is a win-win endeavor for vendors, as even minor penetration into a new market can mean more profit for their companies.

One approach to this feature-adding tactic is to simply roll out the new features with each revision of code. They can be distributed on new machines, and existing customers can pay a nominal fee for the upgrade. Another, more popular approach is to charge for the new features, without adding new hardware. Simply pay a licensing fee, and a new feature is enabled on an existing device. For chassis-based devices, these new features could be added with a code upgrade, using one of the two previous models mentioned. If new hardware is required, the new features could be purchased as an additional card, typically a minor cost compared with the cost of the chassis itself.

For potential customers, rolling out new features with little or no cost also makes a product more attractive. These customers might not need all the bells and whistles now, but this pay-per-feature approach allows a pick-and-choose menu of sorts, allowing you to pay only for what you need.

Making Your Move

One of the earliest vendor developments was to provide both Layer 2 switching and Layer 3 routing in a single device. The Layer 3 features ranged from basic support for packet forwarding and static routes to full support for routing protocols such as BGP4, OSPF, and ISIS.

More recent moves include adding Server Load Balancing (SLB) and other SLB-related features, such as Global Server Load Balancing (GSLB) or WAN-based SLB, and Firewall Load Balancing (FWLB). SSL acceleration, caching, proxy servers, and other features are also being integrated into a single device or into a pair of redundant devices.

Pick A Card, Any Card

Here are examples of products that have expanded into new territory:

  • Extreme Networks began by developing a Layer 2/3 switching/routing switch platform, and now it has also licensed code from F5 to allow SLB functionality in many of its switches.

  • Cisco Systems bought up other companies that provided SLB functionality. In 1995, Cisco purchased Network Translations for its LocalDirector series; in 2000, it bought ArrowPoint Communications for its CSS series and Netiverse for its CSM blades, a load balancer in the form of a switch blade for the Catalyst 6000 series of switches. (Cisco's Catalyst 6000 series were built to allow tight integration of Layer 3 functionality, an improvement over the RSM Layer 3 modules in the Catalyst 5500 series.)

  • Foundry Networks developed its Layer 2/3 NetIron switches and Layer 2/4-7 ServerIron series, which offer routing and load balancing in addition to the Layer 2 base. Foundry also has a BigIron chassis platform, which offers Layer 2-7 functionality with expandable Layer 2 aggregation.

  • Nortel Networks purchased Alteon Websystems for its Layer 2-7 Web switching platform. Nortel kept the Alteon brand and continues to offer more features in its switch and chassis platforms, such as Quality Of Service (QoS) and more flexible SLB.

These are but a few examples of companies expanding into new markets.

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