Estimating maximum users based on broadband connetion?

[New At It]

If I have a bonded T (3megs) link, how many users can I support if I allocated each user:
1meg. down and 256k up, or 1.5megs down and 256k up. Is there a given rule of thumb on estimating this? :?

[WHT]

From another post of mine:

"i want to be able to support 150-180 .. but because of operations and such i do not expect no more than 90 concurrent users at one time .. if i have 160 subscribers ... "

This is where you have to play the numbers. Say you expect to have 160 subscribers. If those users were in some retirement home, then you might only expect one tenth of them actively downloading (general web surfing, Skype, downloading, etc) - we call that a 1:10 sub. ratio. But I suspect there are going to have:
1) a lot more concurrent users,
2) users doing hard downloading of files, and
3) latency sensitive usage.

That means:
For #1 above - you may have 50% concurrent use loadings, thats a 1:5 ratio.
For #2 above - you may have continuous downloading of files, in an extreme situation that might limit you to a 1:1 ratio.
For #3 above - that means users can
a) tolerate bumps in downloading files (they never know it had a momentary slowness)
b) barely notice a pause in surfing a page
c) really notice broken up voice calls with VoIP, i.e. Skype, Yahoo Voice, etc.
that means you have to have a QoS process in place to prioritize VoIP. followed by surfing, and least sensitive downloading files
(hopefully they DL the files before viewing instead of streaming real time video.)

[New At It]

Thank you, very much, WHT Ubiquiti Guru!

[WHT]

In the past, most WISPs estimated a one hundred subscriber load per T1. Now it closer to only 30 subs per T1.

[New At It]

Does that mean approximately 90 subs for a 3megs T or 180 subs for 6megs T?

[WHT]

Sorta...but you have the statistic probability Erlang Law of use on your side. Possibly 200 to 240 even per six 1.5 Mbps each T1 circuits.

[granlabor]

Here in Brazil the broadband ISPs limit IP connections to 30 simultaneous connections.

Sharing DSL here with more than 4 people is a pain. Most of the time it will result in connection timeout if you have heavy users.

As a work around people install webcontent cache servers to reduce the number of simultaneous out going connections. But it does not work for dynamic page content.

Small WISP will deploy traffic shaping rules to limit bandwidth use. P2P becomes useless because the WISP dedicates only 128k for all P2P connections.

The ISP that do not limit normal use will limit your monthly traffic to 10 GB for a 3 mbps link or 60GB for a 12 mbps link.

A satisfatory figure for Sao Paulo - Brazil is 4 users for each MB of DSL.

[New At It]

Hi Granlabor, you quoted "A satisfactory figure for Sao Paulo - Brazil is 4 users for each MB of DSL".
What is the typical download and upload speed for your DSL?

[granlabor]

The DSL provider will sell:
up to 4 mbps download with upload rate = 300kbps
from 8 mbps and more upload rate = 600 kbps

There is a catch on speed that they don't tell consumer about it:
If the web content (port 80) is on their cache server it will arrive at maximum speed. If it is a new content it will arrive at 128k.

They also apply some traffic shapping. For instance: Bandwidth for e-mail is around 300 kbps for port 25 and 25% of contracted speed for port 110.

By law the ISP is obligated to guarantee only 10% of the contracted speed.

When the WISP resell the link they will maintain from 80% up to 90% average of the contracted speed. Thus dividing the 2 mbps by 300 kbps in four equal shares of 500 kbps for DOWN and 128 kbps UP. They allocate a higher percentage for UPload because average UP speed in normal web surfing is only 35 kbps.

[jetout]

i have t3 link and 120 users

[New At It]

Welcome Jetojetout,

i have t3 link and 120 users

How much bandwidth do you allocate to each user, and what UBNT gear are you using?