The ornamental design for a router, as shown and described.
FIG. 1 is a back right perspective view of the router.
FIG. 2 is a back left perspective view of the router.
FIG. 3 is a right side view of the router.
FIG. 4 is a left side view of the router.
FIG. 5 is a front view of the router.
FIG. 6 is a back view of the router.
FIG. 7 is a top view of the router; and,
FIG. 8 is a bottom view of the router.
The dot dash broken lines and broken lines immediately adjacent to the claim represent the bounds of the claim design while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design. The logo trademark forming part of the disclosure is a registered trademark of Charter Communications Holding Company, LLC.