Port 4567 open on router to 'tram' traffic...Should I worry?

When I do a port scan on my router (nmap 192.168.0.1) the result is:

PORT STATE SERVICE
22/tcp open ssh
23/tcp open telnet
53/tcp open domain
80/tcp open http
443/tcp open https
4567/tcp open tram

Everything pretty much looks normal except for the last one, the tram service on port 4567. What is this? Is it something I should be worried about? I've found a few references online talking about it being a Verizon thing, for updating firmware etc. But my ISP is Century Link. The router is an Actiontec C1000A VDSL.

Using Shields Up! to probe my router, I have found that port 4567 is indeed open to the outside world.

Does anyone here know what the "tram" service is?

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