[SmG Phoenix]

How do you guys make sure there is low or little to no lag spikes. I can't play Halo at all without some major lag. Like I get off Halo and suddenly my ping in ts return to the normal 250+-10. But when I am in Halo it spikes to 300+-100 and even hit 500+-300. I have no idea what the issue is. I can play LoL fine. In Halo these spikes happen up to once every 3-4 seconds and people just warp everywhere making it impossible to hit anyone. The instance where I have no lag, suddenly BOOM! double quick scope headshots and down go top 2 on the leader board.
I can't prevent anyone in my household from fapping or some shit, so don't bother telling me that. Also, I haven't restarted my router in a while. Is that the cause? I really want to actually play some proper Halo and not lag every few damn seconds. It makes me mad.
Help on this issue would be appreciated.