You can get meta-callbacks for device.type and device.ip, concatenate them, and register the result.
That's the short answer. Long answer is it can get tricky.
You won't know which will be registered first, so you have to take that into account. You'll have to use a global to hold the values between the two callback functions, so you have to be sure to reset them at session begin. If there's a possibility of multiple values for one or the other, you'd want to take that into account.
The below is completely untested, unsupported, and probably has numerous typos. Test before production use. Use at your own risk.
local concatDevice = nw.createParser("device_info", "concatenate device type and device ip")