Creating a teleporter is as easy as creating a jumppad. So first of all create another platform where you will be teleported to. I've built one in the first room. Either you use if you want to take my platform or you build one by yourself, what I recommend. Good for practice. Now you can build a nice teleporter out of brushes or you can just load a model. For this open up the entitylist (right mouse button), go to misc/misc_model, choose Quake 3 Model .*md3 instead of sprite *.spr, go into mapobjects, then to teleporter and doubleclick on it.

(Image tele model)

Like in the "Placing weapons" tutorial you will see a lined teleporter model. Place it where you want.

(Image wrong direct)

But now it has the wrong direction. Press n, try some angle buttons and orientate yourself by the XY window. You will see what changes.

(Image right direct)

Now create a new brush with the same height and width like the teleporter inside and use the common/trigger texture:

(Image teleporter trigger)

Convert the trigger into a trigger_teleport (right mouse button click -> trigger -> trigger_teleport). Deselect everything and place a misc_teleporter_dest or a target_position onto the platform you have built some steps before. Again be sure that the entity has the right direction. Easy to see on the arrow coming out of the teleporter dest. Also be sure that the entities are some units away from the wall, because if they aren't, the player will be teleported into the wall and can't move:

(Image tele dest)

Deselect everything. First select the trigger, then the teleporter_dest/target_position and press Ctrl+k. Now a orange/green line should appear, going from the teleporter to the dest or target_position.

(Image line)

The teleporter should work now. But there is something strange happening. If you aren't coming from the front but from the left or from the right you can walk through the model. That's why we build another 2 brushes near the trigger, around the free model parts, put the common/clip (red/playerclip) texture on them and compile the map:

(Image pc)

But now rockets and other weapon shots can go through the model. So select the 2 playerclip brushes again and use the common/weaponclip texture (orange/weaponclip). Now the player and the bullets should get blocked.

(Image wc)

Here you can get the maps for this tutorial (place it into baseq3/maps):

Info: Quake does add one extra unit height when you spawn.
Info: If you connect more than one target with the same name then one destination gets picked randomly for each teleportation.