As you can see, this is the shelf of an older TNT. It is made in 1998 week 48. And it is one of the first revisions.  Remember, the first digit of the serial number is the year of production, the next two digits are the week.

However, even this early TNT was a huge router for very large ISP services. And you could connect three together as an again much larger router.

This is a view onto the shelfs mainbaord. As you see, it must have been a hardly designed board with a lot of fixes.