Telephone systems for your business today enable you to do many things that business phone systems many years ago did not allow you too. There were many different functions that some telephone systems offered by Mitel and AT&T will do that other phone systems such as NEC telephone systems will not.
You will need to research the different features and functions of each manufactures telephone systems before you buy them for your business. You don’t want to spend thousands of dollars on a professional small office telephone system that you got on sale somewhere only to realize once it is installed that it does not meet your requirements for your particular business.
Individual voicemail systems can be bought in order to add or be as a standalone unit for telephone systems. It’s best to integrate your voicemail system and small business phone system all into one that way if you have a problem you can call your recommendations vendor and they can fix whatever problems you are having. Sometimes simple problems can be fixed with a software upgrade for your telephone system even if you have a VO I P. software system.