Licensing is a hard and absolutely vendor-specific problem. Not only that, many vendors, especially the larger ones like Microsoft, have multiple types of licensing regimes that change pricing based on:
- How large you are (either by seat count, annual revenue, or a combination of both)
- What industry you're in (non-profits, education, government, enterprise, large corporation, small corporation, and SMB are all discrete licensing categories with their own quirks)
- How much licensing you purchase (volume discounts vary)
- What kind of contract you buy (monthly subscription versus one time payout)
- Where you are located or where the licenses will be deployed
- Whether you're buying off a master contract, or are making your own.
Especially for the larger companies like Microsoft, licensing is its own career-track and one that more and more often is not found in the SysAdmin/DevOps/SRE office. It is found in either your Purchasing office, your value-added-reseller's office, or the LargeCorp's sales office.
In our company we have one person who specializes in purchasing IT license-bearing software. She handles Microsoft and Adobe licensing, as well as a host of other complex entities like ESRI, MatLab, Apple, Novell, and AutoCAD. It is her entire job to know these things and we've made significant savings because she can focus her whole effort into figuring the fiddly bits out. It has saved us a lot of money. She is neither Server person or Desktop person. When license-servers need setting up I do that, but she provides the license keys that goes into them and all of the legal mucking about that does into obtaining them in the first place.
She's a licensing person, and is mostly the kind of person who can answer these questions. I'm not, neither are people like me. But even she would be hard pressed to answer questions for a 30 person small business, since she spends her entire day enmeshed in a large, public (and therefore governmental) higher-ed organization that has completely different licensing options.
So you're a sysadmin, you're still told to fix a licensing problem, and you don't have that wonderful licensing professional I rhapsodized about. What do you do?
- Ask the company that makes what you want to buy. They'll at least give you some idea what market-segment they think your organization belongs in. You may even be able to buy from them directly.
- Do this especially if your question is on appropriate usage of licenses.
- If at all possible, ask for written answer — it's not unheard of for the sales people of larger software vendors to be lost in licensing details too.
- Ask a value-added-reseller of some kind, preferably one you already have a relationship with. They deal with this a lot more than you do, and likely have such a licensing professional.
- The majors like CDW have whole departments dedicated to this.
- They will keep you inside your market segment in ways you won't even notice (this is a good thing).
- Don't ask your peers, they likely don't know either. This is why your question got closed as a duplicate of this one.