Hi everybody, right now I’m looking to rent a connection for a small wisp. I want to start with 16 or 32 users for now. so.. I would like to give them 128 kbps to each user. Now my question is: With a connection around 2MB or 4MB download but the upload is not that high. Do I need the upload to be the same as download ? I just ask because I saw some people having troubles when to many user connect at same time. I just want to make sure I do all okay. I’ll be waiting for any comments, thanks again for support.
However you divide the download to your customers, make sure to divide the upload as well. When the upload is saturated, the download will suffer greately even though it is not saturated. So, whatever you give them for download, then give them each about 10% of that for upload. (I assume your main connection upload is about 10% of your main connection download).
128kbps is a very low speed. Streaming media and such will probably be a problem for your customers at such a low rate.
Almost every network can become saturated. Even that of the biggest carriers.
You have to work out what you think is an approximate high usage of your average amount of combined users during peak hours. You have to work with a ratio.
The smaller your pipe is in absolute terms, but also the smaller the pipesto your customers, and the bigger these same in relative term compared to the supply pipe, the more difficult it is to grant the full service to several users at the same time.
Compare your network with the city’s water supply. Everybody has a certain pipe running to its house. And the city gets its water from some deposit in a certain, bigger, pipe.
Now, under normal use each citizen can at times use all his services the water delivers to him. Take a shower, run the washing machine, flush the toilet.
So, the water company first has to decide how big the pipes should be running into each house so everybody can have sufficient service, but not to use the same big pipes as in the street. (Imagine a 10" water tap in your kitchen with 8bar!)
The street pipe has to be big enough to supply a street full of houses for their average maximum usage.
After that the water company has to arrange sufficient capacity to supply the city of water under normal conditions. Off course these are the biggest pipes.
So early in the morning when everybody wakes up they will see an increased demand and maybe with a slight drop in the pressure they should be able to deliver since this is not an unusual event.
But now, just in a break of the world championship soccer (or superball or whatever) from the country’s national team where half the town decides to use the toilet, it could well be the demands cannot be met by the city’s water supply.
(Luckily toilets have a reservoir so some buffer is available. In internet we call that a “proxy”. 
)
To demand now that a water company should be able to supply every household with its full capacity under all circumstances and in any event would be ridicule. Supply pipe would have to be enormous and the cost reaching the sky. And 99% of the time not even in use…
In internet the same principle can be used.
Network traffic only has one little advantage. You can setup a system (QoS) that grands some services (Voip, dns) higher preference than other traffic.
(To a very limited level some household have sort of the same with their water system. They have a bigger pipe to their boiler and shower and only a very small one to the toilet. So if now someone takes a shower while the toilet is been flushed, the filling of the reservoir goes so slowly that the person in the shower won’t notice.)
So, specially in your case with your low ´pipes´ you have to think well about what you expect your users are going to do. What the maximum demand might be. And then, to get the best out of your limited capacity setup a good QoS (Quality of Service) system.
Good luck!
thank you very much for the comments.