Cisco Systems RJ-45-to-AUX manual Non−Blocking Switch vs. Blocking Switch

Many types of physical media topologies can be applied to this concept. In this demonstration, we will utilize Ethernet 100BaseT. Ethernet 10BaseT and 100BaseT are most commonly found in the networks of today.

We’ll make an upgrade to the network and alleviate our bottleneck on the physical link from the switch to each resource node or server. By upgrading this particular link to a Gigabit Ethernet link, as shown in Figure 1.7, you can successfully eliminate this bottleneck.

Figure 1.7: The addition of a Gigabit Ethernet link on the physical link between the switch and the server.

It would be nice if all network bottleneck problems were so easy to solve. Let’s take a look at a more complex model. In this situation, the demand nodes are connected to one switch and the resource nodes are connected to another switch. As you add additional users to switch A, you’ll find out where our bottleneck is. As you can see from Figure 1.8, the bottleneck is now on the trunk link between the two switches. Even if all the switches have a VLAN assigned to each port, a trunk link without VTP pruning enabled will send all the VLANs to the next switch.

Figure 1.8: : A new bottleneck on the trunk link between the two switches.

To resolve this issue, you could implement the same solution as the previous example and upgrade the trunk between the two switches to a Gigabit Ethernet. Doing so would eliminate the bottleneck. You want to put switches in place whose throughput is never blocked by the number of ports. This solution is referred to as using non−blocking switches.

Non−Blocking Switch vs. Blocking Switch

21