I forgot that vendors looking for eight figure contracts always tell the truth. Don't mean to make light of this matter, it's a non-trivial exercise. At best, it depends on what your definition of convergence is. The difficulty stems from a number of areas. Any combination of those factors should sound a claxon.
Horror stories abound.
Unfortunately for him, he did not learn until six months later that neither firm had any wireline customers. The owner's manual for his fountain pen contained more useful information. Four of the six firms no-bid due to lack of time. Two of the excluded firms would have been viable candidates. Firm does not even score the detailed responses because it favored one of the respondents.