HELLO RESPONDER,
I am not familiar how to write or ask question in forum ? So the straight i want to describe my present problems getting from my RB 450G. I Have a single public ip with default route to upstream /30.
I have now 16mbps bw running on my RB450G on ether1 port, Couple of days ago i found my router doesn't respond its ip echo reply also could not get response from upstream ip. and could not find the cause. so we change current RB450G with A NEW one,
But same result, no improvement. My RB450G Have some basic firewall rules with the bruite force attack protection. Nat per ip base masquerade rules. mangle rules was one prerouting and one forward rules with no passthrough and finally shape the bandwidth with the Queue Tree. There are two client who are using ovpn with ubuntu 11.10 routed client and windows ovpn bridge mode. They using vpn for transmit voice packet through my RB 450G.
after 24 hours continuous monitored we could not find the solution . the same thing will cause my router hang on sometimes after 30 min or after 1 hours. At last i just reset configuration with live router, after assigning wan ip and lan ip with no others rules instead of masquerade rules, i found the network congestion was no more happening and ping time was stable, no more ping loss problems. and interface current rx/tx over 13mb/15mb out of 16. and also see when ever i put a single line into simple queue and or queue tree the packet loss started and client will be lost there live ips etc.
So what to do in this situation. May i need any high end router or may i run this router without applying queue or managle rules on it.

Please please make some suggestion .. Oh i just upgrade my both Router OS to 5.9 . Mikrotik is my loving router not cheap as well as many more reach feature which will act AS a powerful gateway with few more click. So please make a suggestion for me, otherwise my i will lost my loving tools for my network..