When setting up a SOHO network, you may need to connect several devices, such as printers, fax machines, and PCs, on your network. An efficient and cost-effective way to link these devices is a hub, which serves as a common connection point for such devices in a network. Hubs come in three basic forms: passive, active, and intelligent; each type has a specific configuration in which it works best. So before you go out and invest in a hub, you should consider your needs and your future plans for expansion so you can make an informed choice as to how best set up your network. In this Daily Feature, I will help you decide if a hub is the best alternative for your SOHO networking needs, and if so, which type you should choose.
How hubs work
Traditional hubs don't read the data passing through them. They have no awareness of the source of the incoming information, nor its destination. The basic function of the hub is to simply pass on the received information to all devices connected to it, which includes the sender of the data. Hubs operate through a shared medium technology: Picture a telephone conference call where everyone on the call can hear everything being said. The same scenario applies to hubs, because all devices connected to a hub will receive all the information that's passed along from the hub.
Here is a list of the three basic types of hubs and how they work:
- Passive: This type, sometimes referred to as a concentrator, is easy to remember because it does nothing to alter the incoming electrical signal—also known as a packet—as it passes through it on its way to the network. Because it is not powered and does not repeat signals, the passive hubs are limited in the distance the devices attached to it can be located. The cable that connects the devices to the hub can be at a maximum distance of 300 feet.
- Active: Also referred to as a multiport repeater, this type of hub does affect the electrical signal through amplification of the packet prior to broadcasting it to the rest of the network. Then, the active hub repeats that signal. This, in turn, extends the length of distance attached devices can be from the hub to a maximum distance of 2,000 feet.
- Intelligent: This type of hub, also called a switching hub, is a good choice for businesses—particularly if you're anticipating future network growth. The ability to stack this hub, which conserves space, and its remote management support via Simple Network Management Protocol (SNMP) and VLAN support demonstrate its intelligence. A switching hub can also discern an address, thus delivering its packet to the specified port. Most of these hubs also support load balancing, by identifying the unique address of the machine's network card. Intelligent hubs dynamically reassign ports to different LAN segments, based on the traffic pattern, thus helping prevent the network from being overloaded.
Because hub manufacturers are aware of certain shortcomings, such as distributing all traffic to the entire network, regardless of type, which make their product somewhat less than attractive in comparison to similar market alternatives, they are continually upgrading to improve product functions.
Table A provides an at-a-glance description of the three different types of hubs.
|Passive hub||Requires devices to be equidistant to the hub|
|Active hub||Allows devices to be at various distances due to signal amplification|
|Intelligent hub||Allows for specific packet delivery and supports load balancing|
Now let's take a closer look at the types of hubs and how they might work with your particular network design.
A passive hub is best suited to a simple network design (e.g., linking your printer, computer, scanner, etc.). Passive hubs are easily deployed and reasonably priced. These are probably best used in cases where you share an office with one other person and security is not a concern. Also, when using a passive hub, your home office arrangement should not get moved around, and all of your devices are located within 300 feet of your hub.
If linking your various components together is your only goal, a passive hub with as few as four ports might be suitable. However, I suggest buying one with at least eight ports. The small amount of extra money spent now will save you money later should you decide to add more devices. It will also allow for the possibility of connecting more than one computer with its additional devices to your hub.
In the SOHO setting, an active hub might be necessary if:
- Your SOHO is spread around a distance greater than 300 feet.
- You are networking several computers to one central printer.
- You are connecting a laptop to the rest of your home office equipment.
The arrangements above would necessitate the need for something more than a passive hub—use of either an active or intelligent hub would be indicated here.
The intelligent hub takes the active hub two steps further. The first difference is that intelligent hubs are stackable—they are built in a way that allows them to be stacked on top of each other. Although this may not seem like a benefit, when in a business situation where organization is key, the network administrator will greatly appreciate the space savings.
Second, intelligent hubs contain software that allows them to be remotely managed via SNMP and allows VLAN support. However, the VLAN support may only benefit larger SOHOs or even small companies.
Know how you will be using your network
When you asses your network’s needs for today and the near future, it is important to determine whether your hub will be able to meet the demands that are (or will be) placed upon it. To help you define your infrastructure needs, answer the following questions:
- Is your network an administrative tool or a critical asset for your business? (Note that an administrative network requires considerably less speed and hub size, while a network of critical asset would benefit from the use of an intelligent hub.)
- Do you or will you use custom applications? (This can put limitations on a number of aspects of your network. Pay close attention to distance limitations and networking speed requirements for your custom applications. These areas will dictate the type of hub you must use.)
- Have you defined current and future employee access figures? (If you currently or plan to allow employees full access to all of your computer applications, your network will require a more sophisticated connection. In such an instance, a hub might not be suitable; you may need to look into a router or switch. However, if your plan is to limit the number of users or application access, a hub will suit your needs fine.)
- Do you or will you make use of employee telecommuting? (For remote access of your applications, your network will require, at minimum, an intelligent hub.)
Assessing your SOHO needs
While assessing your need for a hub, keep in mind that a variety of individual devices and causes can hinder the potential of your network's productivity. If you are dissatisfied with the speed and/or consistency you're receiving, it might be more cost-effective to upgrade certain network devices to better suit your needs. For example, if you're using a particular hub and find it inadequate for your needs, consider trying a different type of hub (i.e., try an active hub as a replacement for your passive one, or move up to an intelligent hub).
Most hubs' speed is affected by what the computers on the system are doing. If two computers are transmitting 10 Mbps of data at the same time, there is significant reduction in the rated time, sometimes by even as much as half. Under those conditions, the entire network will operate significantly below the data capability. If speed is what you are looking for, it might be time to look at other nonhub options (such as a switch).
Is it time for change?
There are a number of factors involved in network design or upgrade, which will help you decide whether a hub is suitable for use in your SOHO. The most important factor is your own involvement and knowledge of your network's expectations and needs.
Options that can be considered for change include:
- Upgrading your wiring to a Fast Ethernet configuration.
- Changing your network users' habits to reduce congestion and increase productivity (i.e., reducing the number of programs and/or information available, changing policies regarding streaming media and other large downloads).
- Deciding to change from a passive hub to an intelligent hub.
- Reducing the number of users on your network.
It is likely that a hub will suit the network needs for your SOHO. They are extremely cost-effective and can easily be added to. Just remember that you should determine your system needs and buy accordingly.