The routers are basically based on some of the same libraries and you would think that all routers would operate the same manner, but they do not. As for your issue, I cannot really help much. But most problems, are usually, simple networking issues, or such. For example, sometimes it can be an option that is incompatible with a wireless chipset.
Personally, I do know this one interesting fact that some may not know about this router. If you are to use USB attached storage use the port that is closer to the back. In-other-words do not use the top port for NAS. There is an electrical issue with the board and the ports, and this can cause erratic behavior.
I know some suffer from attached storage issues, and this may help some. But it can still be finicky, which leads me to think that really it may be better to make a power efficient and capable NAS (or buy one).
The settings that matter most will vary from network and needs. My options are all enabled for both radios and also my preambles are set to short. I do also have IGMP snooping, and that is it. I have all the options enabled on my wireless network for both radios because my devices are modern and capable.
As for the lag, you can still be configured properly but experience lag due to another player's network. But I can say that 1.5Mb up can start to slow you down in some cases. Especially, if others are using the network. You have only 187,500 bytes a second egress. Around 8Mb/s is where you start to have some head room because that is 1MB/s that is possible egress. This is a lot more headroom to work with multiple users.
I hate lag too, but with consoles you are basically in a set standard for gameplay. The only way you can make it better is how you connect it and connect it with. I always use Ethernet for gaming, and if not possible I will do everything to make it possible. I also would rather use a wireless bridge if I had to Wi-Fi. I would never be caught dead using a USB Wi-Fi adapter for gaming.
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http://en.wikipedia.org/wiki/Network_address_translation ) NAT will affect the relationship of the packet traversal. You basically create a segregated network that will need translation of a public network to a private network and vice versa; especially since it is one public IP to many private IP's. That segregation differs with various NAT's, with some allowing more loose rules to the packets. Now one thing to note that NAT can and usually adds some security to a network, but it is inadvertently done so. But due to this NAT has become an expected security measure due to the segregation it creates.
Because of all of this some packets, which are based on particular connections, don't work well and need a little help to work with NAT. These are gateway applications, ALG's (
http://en.wikipedia.org/wiki/Application-level_gateway). UPnP and NAT-PMP helps too, basically, in the same manner. In other words if you wish to run a server you have to have a service running that allows connections, then the router has to have ports that allow packets to traverse to a host. If these ports are not allowed, or the NAT is too strict then a connection may not take place because the packet cant traverse from the Internet to your private network.
I always use restricted and it is perfectly fine and the best NAT for MY network. Note, I have all the ALG's enabled; and note that sometimes they can impede rather than help too, which means that they should be disabled; if that is the case.
http://en.wikipedia.org/wiki/Network_address_translation and
http://think-like-a-computer.com/2011/09/16/types-of-nat/
I think this project is the best 3rd party firmware project for a router. He has everything up to date, which with Linux can help a lot, and at times cause a problem (gotta love Linux). For example, going to the 3.x kernel solved soft IRQ's issues that are actually solved with a latter kernel, but for some reason no one complies a more modern kernel. 3.x also has better drivers and support for USB, better network handling of the protocols, etc.
They also keep everything up to date and recent, and they make sure the high performance is always a standard. That is unheard with many 3rd party projects. They have resolved many issues that Asus would never fix (some years later), and have added many features such as VPN and IPv6 to this router. Please give them a tip in the jar for their hardware work. Send them a mail with some respect; they deserve it.
iTunes server? Just to use something on a host does not necessitate the need to open a port. Ports only needs to be configured if something is trying to come into your private network. For example, to FTP to your PC you will need port(s) opened, depending on the type of FTP, for someone to connect. All packets will traverse through the NAT when YOU open that connection. Hence, the NAT table; the relationship of the connection that are created. This will do :
http://www.firewall.cx/networking-topics/network-address-translation-nat/228-nat-table.html
I agree tremendously. Ever since 027 build many drivers have been updated and performance has increased. The past few updates resolved minor issues to that and made it even better. That is what I love about this project-making this router the best that it can be. You would never see that with many companies. Thankfully, there is Linux, and thankfully there are those that can work with it.