Troubles with E4200. Forwarding and other.

Question

Have problems after the auto update(it goes 2.0.37 firmware on linksys e4200) from the router web-inerface.
I can't forward rdp to an inner server (no telnet connection to this port at all on a real ip, telnet to 80 is ok). So i have some questions:
0. How to know my serial and version of my router(1 or 2) if i can't take it in my hands now(it works in our new office far from here)
1. How to open linksys .CFG file to check and correct my cofig ?(because in notepad++ i cant open it )
2. When i do port forwarding(single port forwarding) for rdp from 3389 to 3389 on the local ip, i have to do port triggering on the same port, or not ?(of course rdp is open on my server and i check - it is works good in my inner network)
And when at all i have to do port triggering ?
  I have some problems with sip: i have done single port forwarding to my sip gate, and although port triggering there. So i could not hear my opponent when i call(he hear me normal), till i have disabled port triggering. I cant stand what this option done phisically ? As i said before, after updating firmware sip forwarding doesn't work, like a rdp, remote connection to router and others. I know how to do it on MS ISA server, but here is no different inbound and outbound connections options.
3. How to connect through telnet to check config manually, and where to find manual about console commands ?
4. I have ip cams(rvi) and they have web-interface to watch them through web-brouser(it running some activex component under IE), so to forward them i have to forward 3 ports: control port on 30001, rtsp port on 554, and http(i change it to 5555). Hot to forward them correcly, because it didn't work even on my previous firmware ?
5. Maybe some another options block my connections ?
6. If it is firmware bug, where to find stable firmware(what version) to downgrade it ?
All the week trying to config it, but cant stand how to do it((. Need help.
Thank you for help and excuse me for my bad english.

Answer 1

Try port range forwarding instead(you can also try Single Port Forwarding) instead of using port trigerring. You also need to assign a static ip address to the device where you will open that port(e.g game console or ip camera). Open those ports on the router's ui and check uncheck "filter annonymous internet requests"(you can find that under security then firewall if you are using cisco connect cloud). Check if if the port is open by using this link:http://ping.eu/port-chk/.