In this chapter, we've identified the pitfalls of NAT and if even one reader is spared the searing pain caused by a first encounter with an ALG or NAT router then our journey into madness was not in vain.

We've also covered most of the options you have in FreeSWITCH to mitigate NAT-related problems. Before we move on to VoIP security, I'll leave you with a few more tips so hopefully you will get things working even when plagued by NAT. The following are the tips you should remember:

• Learn the four pitfalls of NAT and keep your eyes open for them
• It's very easy to get distracted and fall prey to one of the pitfalls. If you notice it's taking too long, start over and make sure that you haven't made a mistake somewhere that is leading you astray.
• Try to make the least changes necessary to get NAT working
• The more you mess with NAT settings, the easier it is to do something wrong or make things incompatible. It's very easy to get one end working and break the other and go back and forth for hours at the mercy of the second pitfall.
• If you have access to your own router, configure it to make conditions as favorable as possible for NAT
• The best way to make things simple is to tune your surroundings so you have the ideal environment. Choose basic NAT settings and stick with defaults that are usually tuned to working the best for the majority of cases.

In our next chapter we will change our focus from overcoming NAT issue and look at ways to improve VoIP security.