There must be a few more details about your situation that would be helpful to know to answer, but ...
TTL should work normally on the hot shoe, no cable.
If you mean TTL as an external flash, you can use it wirelessly (in its SL mode) using a Nikon Commander, if you have a commander.
Or you can use a hot shoe extension cord (like Nikon SC-28), but the flash will be limited to only 3 or 4 feet from camera (the coiled cord tension tends to tip over a light stand). Other than this hot shoe extension cord for one flash unit, there are no cables involved with iTTL flash.
Thanks Wayne. Sorry I was short on details, I was posting right at close at work and was getting rushed out the door. But I think you did answer my question. One thing I'll be shooting is events and will be using a flash bracket (old school I know) , so I'll need the SC-28 for ttl right?
Yes, the hot shoe cord would be the best answer for TTL.
But an alternative, for TTL, instead, if your internal flash has a commander, it probably would work that way, from Commander into SL mode, without a cord. I'm not sure it is supposed to work since it is not line of sight up there, but it always seems to work. Because it is close I guess. However, that adds commander flashing in the face of your subjects, which will cause them to blink in the picture. FV Lock would be the work around for that blinking.
But the hot shoe cord is easy and most direct failsafe way.