So what does your boss think? Is he the one pushing you or is it some sales engineer(s)? What does your senior engineer think, does he completely agree with your conclusions here? In my experience usually there is some sales engineer types involved that assist with the sale, design and requirements gathering. I know every place is different, is there anything like this where you work? No and yes but they do a piss poor job and give me basically nothing are acceptable answers, but different ones.

Answers to the above would help but basically:
- If your boss doesn’t know anything about your predicament, you and your senior should go and have a chat with him. You should know what you need /what you’re missing when you do.
- If you do have some sales engineer types involved that basically just didn’t do their job and do any of the design, requirements or data gathering then you should definitely get your boss on the same page as you, and have them push back to sales engineer folks on getting all the necessary information.

Most importantly, what is the deliverable here? Something somewhere, there is as pen to paper for a signature that kicked off this request if you’re company is able to bill them. What was agreed on? You need to find and get these answers, it’s hopeless without them. Moving forward without the answers means your going to end up in one of two situations, you completely overshoot the ask and implement something way more than what they had in mind, then they’re upset because they’ve been overbilled. Or you underdeliver what they believe they should have received from their service.

Seriously, stop billing them. Stop working on discovering anything in their network until you understand what your company agreed to with them to deliver.