RTP packets/Port block/I don't know. Help

[calvin_baank]

Ok everything was working perfect..
Linksys PAP2 firmware 3.1.22(LS)

US.VOXALOT.COM server port 5060
Followed everything in the stickpost.

All worked like a charm.

Now suddenly one day i'm having problems i can't connect to voxalla anymore...

Tried other server everthing... Finally changed the port to 4060.
Thought port 5060 was blocked.

It connects again...
I didn't run any test futher..

Yesterday.

I found a problem. I can't receive voice after a while... RTP packets stop @ 900-950 packets every time...
Well i guessed block port but thats not the case...
because i can send an URI call to my router on port 5060

I was like WTF...
I disabled stun. And i can connect on port 5060..
With stun no matter which one i try or which settings

1)Substitute VIA Addr: Yes
Send Resp To Src Port: Yes
2)Handle VIA received: Yes
Handle VIA rport: Yes
Insert VIA received: Yes
Insert VIA rport: Yes


If i disable STUN and connect on port 5060 to voxalla it works.
But everytime the packets stop at 900-950 You don't hear anything anymore...

I want to know if it my modem or Linksys adaptor or ISP..

I'm going really crazy

Modem(UNPN)+4 port LAN->Linksys I can't do DMZ because i can't access my
modem is locked(password). I can portforward with UPNP to PAP2.

Any advice would help

I enabled logging on my PAP2

Testing:
Stun.xten.com methode 1 stun settings
Port 5060 default
Nothing comes back NO SIP MSG

stun.xten.com methode 1 stun settings
Port Server 4060 Port sip 5060
Connected and working
RPT packets stop/no echo test

Stun.xten.com method 2 stun settings.
Port Server 5060 Port sip 5060
I see there are replies coming from the server byt i get the following sip msg
SIP: MBUF OVFL 3687/2559

Stun.xten.com method 2 stun settings.
Port Server 4060 Port sip 5060
Connected and working
RPT packets stop/no echo test
Call drops after a short time
This is funny the PAP2 reboot before call gets dropped(coouldn't reproduce it)
----
Sipura 1001 firmware:
Stun.xten.com methode 1 stun settings
Port Server 5060 Port sip 5060
Connect
No audio..
No RTP packets send nor received

Stun.xten.com methode 2 stun settings
Port Server 5060 Port sip 5060
Connect
No audio..
No RTP packets received
No RTP packets sent

Stun.xten.com methode 1 stun settings
Port Server 4060 Port sip 4060
Connect
Working again
Reboot the PAP2 doesn't work RTP stop @ 945 packets

WTF

After playing with codecs it works sometime most of the time not.

I THINK IT'S VOXALOT RELATED...

Edit:
I have setup voipbuster on line 1 port 5060. Stun.xten.com..
No problems at all...

Martin Please help