|What you connect at each end is going to depend on what you have now, and what you wish to provide. What do you presently have the incoming internet connection connected to? Most people use a SOHO router.|
This idea of customer access. Is it necessary? Is it important to your business?
I ask because if you plan on having sensitive data on your business network that you do not wish to give customers access to, then that changes how you're going to do things.
If you have sensitive data, I'd advise you forego the customer internet access altogether as this is the least expensive solution.
If for some reason you must have that, and require segregating your business network away from the customer access then you have limited choices.
1) Pay for a 2nd internet connection and buy a second cable/repeater and pull both. Use one for business only and the other for customers only
2) If possible, pay for a second internet connection, have it installed in your other building. Use it only for customers.
3) Buy L2 VLAN capable switches (two, one for each end) and utilize VLAN's to segregate the two networks.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.