Help setting up the obi202 behind the router

[Hyrules]

Hi, I'm having some stranges issues with my obi202. I'm trying to set it up behind my router (RT-N56U) and for some reasons sometimes it works ok sometimes i can't hear the person on the other end of the line but i can hear them. I simply cannot use the OBI in front of the router because it's not powerfull enough to support my 60mbit internet connection. I have all the ports forward enabled. Any help would be appreciated because i'm on the end of the rope here and i'm almost going back to videotron's phone service.

[Hyrules]

I might have found the problem... damn sip helper... in the latest firmware there is now way of disabling the sip alg. Unless you connect in telnet and disable it manually

nvram set nf_sip=0
nvram commit

for those who have asus routers it might help.

[QBZappy]

Hyrules
That router is the bomb at the moment. It doesn't look like you have installed Tomatoes firmware on it.

[Hyrules]

Is it possible to install tomato on it ? I thought Tomato couldn't work on it...

I know it's the best because I bought it because of that.

Update : Tomato does not work on it because of it's ralink chipset. Although there is a custom firmware for it named Padavan.

http://code.google.com/p/rt-n56u/

[QBZappy]

This may be based on oleg firmware for Asus routers. (not sure). Seems to offer many of the features in Tomato firmware.

This project is a try to build complete working environment for ASUS RT-N56U/RT-N65U.
http://code.google.com/p/rt-n56u/

Discussion thread on above firmware:
http://vip.asus.com/forum/view.aspx?id=20130106001949712&board_id=11&model=RT-N56U&page=1&SLanguage=en-us