America's Army/Mountain Pass Tactics

Defense sniper
Preferably this is using the m24, but the m82 will work too.

If your team is in need of help (aka defense is losing), then take your trusty sniper and run up low defense peak and get behind the fallen tree (Southwest Landslide I think).

Crawl into the tree until you can only see south cp. Don't get too far out or you will be visible.

Snipe any rushers to south cp and stay put unless any get by... if that happens then move around to get a clear shot and take it.

If you are still alive later in the game (after 3 minutes of play) then keep an eye on the top of CP and maybe move over so you can watch the west defense ledge and defense road. Some people just like to run right to the objective through here... take them out and make sure they never try that again.

NOTE: CP = central peak

Assault
One route that is almost always overlooked is through the valley. Go left at the assault spawn and run through the valley. You can usually get behind defence this way. Defence can also use this to get behind assault.

Running through the valley on assault is probably the worst route to take. You are at a severe height disadvantage, and you have to go through a "choke point" exiting the mouth of the valley. One well placed player on defense can handle any assault players attempting to go through valley.