Futures and Options on Futures Quoting Techniques

Hey everyone,

I have a question no research paper and the exchange websites seem to be able to answer.

Currently, I am looking at some price discovery issues between commodity futures and options. My HF algos come up with results that leave me with questions. Especially natural gas seems to behave differently than others.

Anyway, my question is: How are quotes in futures and options created? I know in equity options, market makers do auto-quoting and rely on the underlying stock (thus, stocks lead options by some microseconds). However, CME writes on their website, commodity futures options have the order type "Quote Request". That means, quotes are sent to dealers/specialists, which sound strongly like an OTC market. Is this the case?
In that regard, how do market makers make quotes in futures?

Does anyone have info on the difference between quoting techniques in futures and futures options (and equity options)?

Thankful for any input!

Cheers
Mike