Speeding up your networks

Black Box offers many excellent and cost-effective products that can help you improve your network’s speed. And as technologies like Gigabit Ethernet, Virtual LANs (VLANs) and Ethernet Quality of Service (QoS) become more widespread, even the most bandwidth-intensive applications, such as real-time voice and video, need not be limited by LAN speed restrictions.

Add a switch…or several!
In a switchless application, all users share the same 10 Mbps of bandwidth, and only one network computer can transmit at a time. The rest can only listen. And what about clients capable of running at 100 Mbps? They’re restricted to sharing that same 10 Mbps because hubs can’t connect devices of dissimilar speeds, and autonegotiation results in the lowest common speed. To speed up your network, you should first consider adding a switch, especially if you’re working in a 10-Mbps Ethernet environment and use only hubs to connect users and segments.

An Ethernet switch is a device that learns the physical addresses of the devices attached to each of its ports and forwards traffic at high speed based on those addresses. The switch segments networks into collision domains by port, enabling dedicated rather than shared connections between communicating devices. It can also connect segments of different speeds.

By adding a Black Box® 10-/100-Mbps Ethernet switch to your network, you can isolate traffic to the segments for which it is addressed and reduce the number of devices competing for network bandwidth. Each switch port has 10 or 100 Mbps of bandwidth for attached hubs (and if you use full-duplex operation, you can simultaneously transmit and receive data in both directions and provide doubled speed in point-to-point transmissions). What’s more, your 100-Mbps devices will run at their maximum speed and use the switch to communicate with slower equipment. You can then upgrade your network interface cards at your own pace.

Before and After...

Add a Layer 3 switch and implement a VLAN
The next step in speeding up your LAN is adding a Layer 3 switch. A Layer 3 switch is a fast, limited-purpose, LAN-only router that can be used to connect different IP subnets. Because broadcast traffic isn’t routed between IP subnets, you can use Layer 3 switches in your network backbone to filter broadcasts and free bandwidth.

And by using a Layer 3 switch with VLAN capabilities, you can even control the way broadcast traffic is isolated. VLANs are mini subLANs that, once configured, exist and function logically as standalone, secure networks, even though each component workstation or node is part of a much larger physical LAN. With a VLAN-capable switch, you can not only restrict broadcasts to individual IP subnets, but you can create VLANs that are effectively broadcast domains. These can be based on switch port number, protocol and various other criteria that enable you to maximise your network’s efficiency. Each switch port, for example, can be assigned to support a different VLAN. Ports configured as part of the same VLAN share access to data, and ports that aren’t part of the same VLAN don’t share the data. It’s that simple.

Layer 4 switching
The newest players in the switching game are Layer 4 switches. In addition to using MAC addresses and IP addresses, Layer 4 switches use Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) headers. These headers include port numbers that uniquely identify which application protocols (HTTP, SNTP, FTP, etc.) are included with each packet.

High-speed LAN switches: Keep your network traffic flowing smoothly

Because Layer 4 devices enable you to establish priorities for network traffic based on application, you can achieve far greater control over network traffic than with Layer 2 or Layer 3 switching.

This level of control over network traffic is important because, no matter how fast your network is, network traffic is bursty and you’re going to have periodic congestion—the sort of congestion that forces packets from that important real-time application. With Layer 4 switching, you can give a high-demand application—such as video—priority over generic HTTP Internet traffic.

Switching among multiple workgroups

Use port aggregation and Gigabit Ethernet
If you still need more speed, use Fast Ethernet switch port aggregation. With this, you can combine the bandwidth that’s available to multiple switch ports to feed a single attached device.

Or upgrading to Gigabit Ethernet may be your answer. It is, after all, the ideal high-speed technology to use between your 10-/100-Mbps Ethernet switches.

Placed in the backbone of your network where workgroups and server farms connect, port aggregation and Gigabit Ethernet technologies can dramatically increase the throughput of traffic and remove bottlenecks in even the busiest of networks. And by combining these technologies with the Layer 3 switching and VLAN capabilities of BLACK BOX® switches, you may be able to put an end to your network speed problems!

High-performance switched access to multiple servers