In simple terms, switches are used to interconnect the various parts of a network. As a core component of any Ethernet-based local areas network (LAN), they are available at various bandwidths -- typically 100, 1000 or 10,000 megabits per second (Mbps).
According to analyst firm Dell'Oro Group, 1000 Mbps enterprise switches have been dominant for quite some time, accounting for about two thirds of the market. Their market share, though, has slipped by two percent over the past two years.
More significantly, Dell'Oro numbers show the growth of 10,000 Mbps gear at the expense of 100 Mbps units. While the former has growth from 18 percent in 2009 to almost 27 percent today, the latter has slumped from 16 percent to less than 10 percent. Clearly, 100 Mbps is going away, at least in the enterprise sector. 1000 Mbps continues to take on most of the load, but 10,000 Mbps (also known as 10 Gbps, 10 Gb Ethernet or 10 GbE) is where the field is heading in the long term.
"10 GbE, which is very high speed, has become more prevalent over the last two years as prices have come down," said Sven Rasmussen, networking solution architect at CDW.
He said that data center virtualization has been a leading driver of 10 GbE. When users consolidate and virtualize, they may shrink their infrastructure, but the volume data on the network does not shrink. Thus 10 GbE becomes a necessity in a highly virtualized environment. Bigger pipes are required between servers as all of the information previously spread across a large number of servers is now going through far fewer boxes.
The advent of higher performance switches, of course, bodes well for sales. From $15.2 billion in 2009, Dell'Oro estimates 2011 will end with $19.5 billion in enterprise switch sales. Cisco is the giant in this segment. It has carved itself a massive slice of that pie -- three quarters -- with HP and Juniper taking up second and third place respectively.
Switches in enterprise networks
The average enterprise network generally has a core switch, with additional distribution layer switches that operating below it to bring all the information into the data center and disseminate it out to the access layer where the end users are located and there is less data traffic. This is the most traditional model of core, distribution, and access layers (three layers). Depending upon the size of the organization, though, some can get by using an enterprise switch to serve at multiple layers. For example, if you have a small network and want to have an enterprise switch, you can have a "collapsed core" which involves having multiple layers within the same switch.
"Another key function to explain is that some devices are layer two -- synonymous with switching -- which allows for extreme high-speed," said Rasmussen. "Sometimes, users prefer these switches to incorporate layer three -- synonymous with routing -- which allows the network to be better organized by segmenting the infrastructure into discrete pieces. With good management tools on top of that, it can be more efficient to manage than just one big, busy network with tons of data flying around."
But while there are many switches around, what enables Cisco and its closest rivals to dominate the market is that they offer sufficient back-end infrastructure and support for enterprise users. Cisco, for example, has SMARTnet.
"It is important when choosing a networking provider that you not only look at the hardware specifications, but also at the kind of organization they have to support their equipment," said Rasmussen.