I would like to know mikrotik installations in Real World.
Which is the best network topology to use: Mesh or Routed?
We would like to build a network of about 5000 users, which can support QoS and specially VoIP.
The bandwidth for the single client will vary from 512kbps to 2Mbps.
My Plan is:
To work on the 5Ghz Frequency
To have several base stations, every base station will have 3 120 degree sectors, each sector will be on a different channel and on a different board(RB600A or RB433AH). Also in every base station we should have one or more PtP links for backhaul with the other base stations. Also this PtP links will have separate frequencies and we would like to use Nstreme2 for this PtP Links.
The plan is to use a fully routed network so each sector will have a different SSID, different frequency and different IP, so all can transmit simultaneosly.
Working with this idea We would have very good throughput but the problem is that we will need a lot of frequencies and we don’t have to much.
The 2.4Ghz band is polluted and we cannot work.
In the 5Ghz band we some frequencies(about 5) on which we can work.
But how can we operate on a Base Station on which we have for example:
3 Sectors using 3 frequencies
1 PtP Link using 2 frequencies because Nstreme2
And we would like to add another PtP link?
And what about Mesh is it good, I don’t like it to much because all the network will be in a kind of bridge and so every AP will be syncronized with ather AP’s for transmiting.
The mesh setup is more fault-tolerant than routed. It gives you the ability to choose the best route to the gateway, even if one ap fails.
But, if you are like me, and have a ‘need for speed’, then routed performs the best. But you will need to be on top of it tho. If a backhaul fails, it could take out several aps.
I would start the setup without the nstreme first to see how the performance is. I gotta tell ya, the performance on a routed wireless net with 5GHz backhauls is amazing! And remember, the 5GHz band frequencies do not overlap like 2.4GHz does. All are available in the same location with a little care.
ADD: I use the 2.4GHz band for the client connections and the 5GHz only backhaul. That gives you a lot of frequencies!
I cannot use the 2.4 Ghz because it is very polluted.
I have only 5 channels in 5Ghz on which I can operate, so if I use 3 of them for sectors, remain only 2 for the same location which I can use for backhaul. But what happens if on the same location I will add another backhaul or more?
In the figure below can you give an example of frequency assigment.
As long as your p2p shots are not too far (your power is not too high), and your selection of dual band dish is suficient, you should be able to use 2 p2p shots with enough antenna spacing and angular seperation.
buy the frequency license for 10$
than put your PtP links in another frequency than 5.8ghz like 4.9ghz or 5.4ghz
you can use r5h since it supports different frequencies with the proper license
Not much information given for any good help. What is the coverage area? how many base stations are you going to have ? etc. i tend to think that with 5000 users some could be falling outside the 2.4 polluted area.. Try very much to use 2.4 where you can and leave the 5.8 for the backhauls. as suggested R5H has numerous channels you can wrok from 4.9-5.8. Maybe you could use them and have the backhauls operate on 5.4 or 5.1
As I sayed before I can only use 6 channels of 5 GHz band because other are full.
Which will be the best Mesh or Routed Network??
The coverage area is about 5 x 5 km, Initially we are planning to use 20 AP and than to add as needed.
2 x 20MHz channels for PtP,
6 x 10MHz channels for PtMP, as you only want <=2mbps.
Plan your cells carefully and beware of ghost frequencies when using 5/10MHz.
Routed is best!
You may even tunnel the client into the core.
Use OSPF for failover/loadbalance on the PtP.
In routing mode with 3 different frequencies and different SSID also different network I am sure that the 3 radios can transmit simultaneously.
If I have 3 radios and 3 sector Antenas, all with the same SSID and the same frequency, in Mesh or Bridge can thay transmit simultaneously, or the 3 radios act like a big omni???
sure they can! however not always as they are NOT synced.
with same freq they will interfere with each other when tx/rx unsynced, or you need ant with good front to back ratio.
same SSID, diff freq is ok.
your 3 sectors will not be like one big omni with Mtik.
they are not like an omni because they are different radios. they can transmit simultaneously. they can only be like an omni if you use the three antennas with one radio using a three way splitter.
with same freq they will interfere with each other when tx/rx unsynced, or you need ant with good front to back ratio.
same SSID, diff freq is ok.
your 3 sectors will not be like one big omni with Mtik.[/quote]
But if I put them in mesh I must have also the same frequency. So if I have all the three sectors in mesh with the same SSID and same frequency and in the same network how is possibble that they can transmit to three different clients one per sector?
of course you could still configure such. will they hear each other well?
mesh nodes cannot tx simultaneously, they listen then repeat. (a function of TDD)
when sector A Tx, client A, sec B, and sec C will Rx.
then sec B and C will Tx, client B and C will Rx, sec A will ignore Rx (as it was the source, but listens for ack), however client A may Tx, which reduces performance.
usually, mesh is better with different bands for backhaul and distribution, (2 wlan).
choice of ant will depend on location of the nodes and mesh groups.
