Please note - Ndiyo has now officially closed its doors, at least as a legal entity - but we've kept the site alive in case any of the information is useful to others.
Our thanks to all those who helped out and were involved in so many different ways! The Ndiyo legacy lives on in the ultra-thin-client work at its spin-off DisplayLink, at Plugable, at NoPC and elsewhere...
Hubster Limitations
So why aren't all multi-user systems built this way?
There are some limitations to the Hubster concept which means that it's not suitable for all situations, including...
- Distance
- This is perhaps the biggest issue. USB 2.0 connections cannot be more than 5 metres (15ft) long. In theory, you can insert a powered USB hub and go another 5m, and possibly repeat this more than once, to give you quite reasonable distances. But USB is not designed for it in the way that Ethernet is, and may start to give problems if you push it too far.
- However, in situations such as small workgroups, modest internet cafes, children's playrooms, temporary offices, this is not too much of a problem. A single PC in the centre of a circular table could support quite a number of terminals around the outside, even if limited to a 15ft radius!
- Robustness
- USB networks tend to react less predictably than ethernet ones to accidental disconnections, power losses, and so forth. USB hubs are not all created equal, and some behave much better then others when stressed.
- This is balanced to some degree by the fact that they can be easier for ordinary users to understand, and if things go wrong, unplugging everything and plugging it back in is often a solution.
- Switchability
- Imagine a situation where you have three servers and thirty terminals on an Ethernet network: ten terminals per server. If one of the servers dies or needs to be switched off, the others can automatically support its terminals and share the extra load. The mapping between terminals and servers is configurable in software.
- For situations where the network wiring is significant, such as Hubster, a reconfiguration such as this can be much more complex. This also applies to systems based on using multiple graphics cards, such as the ones from Userful and Novell partner Omni Technology Solutions. Fortunately, unplugging and replugging USB connectors is much simpler than doing the same with graphics cards!
All systems have limitations, and we are aware of those that affect Hubster, but we think that its benefits will outweigh the disadvantages in many scenarios.