Hi Guys,

Does anyone have a good method for calculating how many users can share bandwidth.

I understand I will need to configure traffic shaping on the router (RB1100).

My router is located in a datacentre with a 100Mbps port. I get charged per Mbps.
For instance, if I want to sell 10Mbps packages to my clients, how many users would you suggest I service on a single 10Mbps 1:1 connection?

Btw, I have no limit on incoming speed - it just costs money!
Thanks

Hello,

I personally did something else. I wanted to keep the bandwidth consumers at a low limit while allowing the decent users to go as fast as possible. This is why I used the burst feature of the traffic shaper. I'm allowing them 50Mbps under normal conditions but if they have a sustained throughput over 5Mbps over a 120sec period, they will get limited at 10Mbps.
All I can tell you is that for about 80 VPSes I had about 20Mbps traffic as indicated by the 95th percentile Cacti graph, yet everyone was very happy with the speed.
My problem was with the bandwidth consuming VPS clients that run Shoutcast servers and this problem was fixed by capping their speed at 10Mbps. The burst feature however allowed me to offer more bandwidth to the non-abusers.

Thanks.

Hi mihaialdea,

I can see that that would work really well in a hosting environment.
My services are to sell internet access to business and home users, I'm worried that the clients that buy the faster packages will be the users that want to hammer the connections for downloads.
I presume most ADSL ISPs offer a burst..I guess I need to work out how I should limit it.

Any one else?

What you are asking for has many answers.

You have contention ratio, meaning how many times your bandwith is sold.
For instance, if you have 2Mb but 10 users allowed to have 1Mb each, then you have a contention rate of 1:5
Meaning each Mb is sold 5 times.
But you can see it only takes 2 users to completely consume your bandwith.
The bigger the supply pipe compared to the pipe you sell the higher your contention rate can be. So usually ADSL-ISP's has 1:40, meaning each Mb is sold 40 times.
But with the higher demands (streaming video, Skype, P2P) this is not good enough anymore because capacity demand from users last also much longer then in the early ´internet days´. So many providers are going to 1:20 or even better.

It is also important to realize that 1:5 with a 1Mb:2Mb client:supply rate ratio is much worse then a 1:5 with a 10Mb:20Mb client:supply rate ratio.
The latter can actually have a higher ratio (more ´double selling of your Mb's) then the first since the possiblity of 2 users demanding 10Mb at the same time will be much less then 2 users using 1Mb at the same time. But as stated, this is also changing with the ever increasin demand for bandwith from customers.

QoS also has importance. If you can separate lesser important traffic (file share/P2P) form highly important traffic (VOIP, dns) and give latest highes priority on your network then even when you reach your ceiling it is the low importance traffic that is starving first before the high importance. This way you can still guarantee VOIP and or browsing of one client only at the cost of the temporarily degrease of speed of the other clients P2P session.

So, to answer your question you need to know how many users get how many bandwith assigned, what is your pipe line capacity, what service is allowed agains what priority?

5 variables to work with....

(Plus it will also make a difference if you have a wired network or wireless. Wired is full duplex while wireless is basically simplex. So a wireless AP with x many client with Y connection speed can never reach same maximum trhougputs as same clients wired into a wired AP. And then we even leave maximum airspeeds out of considerations....)

I’ve been managing a small wisp for all most a year. We took the wisp from a company that was going to pull the plug because they were losing customers and weren’t making money anymore. I was told this company at one time peaked at 350 customers and then tanked. When we took it over we were also told there were 120 people left. Turned out to only be 70. To start i got a fiber connection at 10/10 and it lasted up until 2 weeks ago. We now have 150+ and the 10/10 wasn’t enough anymore. I had the connection speed set at 15/15 and we are now back to adding more customers. We currently offer our customers 3/1 and service is working great. From the time we took it over i have been fixing all kinds of things physically and re designed and re ip'ed everything. The network is canopy ap's with MT routers and a mix of BH units from MT to canopy to a few trango units. I would be curious if there was a better faster way to manage the customers speeds other than a queue tree based on pfifo.

For me the 10/10 was enough to service 150 or so users at 3/1. I think in your case you will have to play it by ear from the start and see how much traffic is really going to be used. As stated a wireless network is different than a physicle connection. Sorry to hijack your post but I too have a question. Is there a better or faster way to manage the customers speeds other than a queue tree based on pfifo. I have been reading on the pcq queue tree and testing on office MT router. I don’t see any difference.

Guys, you have answered my question.

Thank you!