Deploying and raising a small business office from scratch, what you need to know?

Question

Computer networks

How to correctly build a network?
What equipment for 30-70 PCs to buy? (Network)
Servers - AD, DNS, DHCP, Cameras, Skype, Mail, Share, IP telephony, 1C (how to distribute everything?)
Users 100 (Approximately)
There will be a VPN between two offices
It is desirable to use VLAN (Let's say - some ports for cameras , some for printers, etc.) I’ve already seen everything, but how to raise everything myself, until I put my mind to it
Plus, I would like to keep all programs on the terminal sessions
Budget (not Cisco, well, Microtik or something else, on Cisco doesn’t have such tools)
Don’t kick too hard, I’m learning, I’m delving into, I want to know everything
I would also like to use a patch panel + several switches (because this is an industrial enterprise and about 7 buildings will be at different distances).
I want to hear the pros and cons and all the criticism

Answer 1

You don't have a question. You have a decent size of TK for a decent office for laying networks for decent money :)
Here, in order to more or less competently advise something, you need to get a huge pile of information, digest it and give some advice / project etc. Who is going to do this for free? Either hire designers, or if you butt heads yourself, ask specific questions.

Answer 2

First you need to know exactly where the office equipment will be located (workplaces, office equipment, cameras, phones, etc.). Then you can think through the issues of internal communications in detail; ideally, all network connection points in a building should be brought to one room, which houses switching (and, possibly, server) equipment, but this will not work for large buildings, because the twisted pair length limit of 100m from the subscriber to the switch is simply not enough ; you have to use several rooms or hang cabinets with switches in the corridors. Of course, the points of presence of network equipment and servers will need to be provided with sufficient power supply and, if necessary, cooling. And then, depending on the number of incoming cables in a particular room, you can choose switching equipment, draw up a diagram of its connection and engage in implementation. If possible, you should not breed a zoo from different types, so that later it would be easier to administer.
Also, if we are talking about several buildings, you need to immediately consider the possibilities for connecting them to a common network.
As for server rooms, if possible, they should be placed in different buildings and connected by direct communication channels. Place software on them so that a server in one building backs up a "colleague" in another.
Farther. It will not be possible to lift a large network alone; too much manual work on installation, connection and settings. You need to connect fellow assistants.
For servers - first decide on the software for the tasks of all departments of your company. Then you will estimate the distribution of programs on servers, taking into account the above, and you will be able to understand how many servers you need and for what, where each of them will be located, how much electricity and cooling is needed there.
For anything more specific data is not enough. As the drafting (and further implementation) of the project, specific issues will appear that you will already solve.

Answer 3

I am complete. I support the previous speakers, you need a competent system administrator for this whole thing. If you do one, the business will lose a huge amount of money on downtime of non-working services.
It is better to hire a person, you can know, at the same time and learn
If on the question -
How to router - zeroshell or pfSense. Well, or pick up Mikrotik. These are dhcp and DNS
Switches - to taste, simple or managed, depending on locations. If far apart - better manageable, so as not to run. (Yes, always better managed, so then)
Mail server - on Linux, software of your choice.
AD + share, skype, telephony (Asteriks), - I would buy one server, and then raise virtual machines. in this case, if anything, it will be easier to move them to another hardware
1c - transfer to a separate server\
And where will the file storage be? - I personally use OenMediaVault for this - a separate machine. in principle, you can connect to the first PC (where AD) if these are virtual
Cameras - to separate POE switches, and to a separate port on the
Terminal Server router - if all 100 users, then a separate machine will calculate the load.

Answer 4

Divide the project into 2 parts:
1. Physical network for buildings/objects
2. Software/server part + operation logic.
For the first, call local experts and build a network. Preferably immediately on the optics of the highway and copper inside buildings.
And with the second here a pack of separate questions.
If Internet channels allow, then take everything to the clouds from the territory of the plant. Terminal servers, cloud PBXs and in the field only need the Internet and it is easier to transfer users ...