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New Member

PAP2T Voip adapter - no ready line tone and no way to call or receive incoming calls

I just bought the PAP2T-EU in the Internet pc hardware shop so there is no restriction from the Internet provider.

I  managed to configure it in such a way that it is connected to the  Internet (trough the Linksys X2000 ADSL2+ router) and it is receiving an  incoming calls, but only in the info screen of the web interface. Here is the screen with the details.

However my problems are following:

  1. I do not hear any tone when I pick up the phone. Normally there should be continuous sound indicating readiness of the line.
  2. When I try to make a outgoing call then there is no signal that it is connecting. Also the connection can not be made.
  3. When  I try to call in my landline from outside, then I only see the status  in the web interface of the PAP2T, but the phone is not ringing.

Before  I was using the Zyxel ADSL2+ Voip modem and I had no such problems. But  now the modem died and I could not find anything which would has all  the options I need in one box (ADSL2+, Voip).

I used the setting as for the Zyxel from here,  but somehow I'm missing some configuration options to make my phone  works with PAP2T. I also tried with another basic phone, but with the  same effect.

Please advise what should I change from the default factory settings to make this work.



Hall of Fame Super Gold

PAP2T Voip adapter - no ready line tone and no way to call or re

Wrong forum, try "small business - gateways"

New Member

PAP2T Voip adapter - no ready line tone and no way to call or re

I see a couple of questionable status values in your PAP2T screen capture.


The Line 1 Status - "Call 1 Tone" is showing a status of:  "Ring - Hold".

When my ATA rings, this status just says "Ring".  So, not sure why yours is showing the Hold value.

But, that my be inconsequential.  Not sure.


Your Status value for "Mapped SIP Port" is blank (empty)

My ATA is showing the value 5060 for Line 1 and 5061 for Line 2

Double check your Line 1 settings and confirm that SIP Port value is set for 5060 (the Default value).

If that is correct, then have you set your ROUTER to Port Forward or Port Trigger on SIP Ports 5060 - 5061.

Make sure your ROUTER is also Port Forwarding or Port Triggering RTP Ports in the Range 16384 - 16538, which the PAP2T defaults to use.


I also note "Port" status value for Line 1 is:   "16432 >> 0"

I think this also illustrates a problem with Port forwarding /triggering through your router.

My "Port" value shows:   "16432 >> 16432"

The fact that your port value after >> is "0" looks like a port issue.

This blog post illustrates how my PAP2T is configured to successfully work with CallCentric:

Some of the illustrated settings may vary from your VoIP provider.  So, be sure to consult your VoIP providers recommended settings for your provider specific settings.

Regards, and good luck.

Jeff -

New Member

PAP2T Voip adapter - no ready line tone and no way to call or re

Thanks Jef for your reply and help.

I try to follow your guide and put the same settings appropriately using the info I found in my provider wiki page. Unfortunately with no luck. I set up the port forwarding like this, but the result is the same as before. The only difference I did was setting DNS SRV Auto Prefix:  No as with Yes it was not registering to the Voip service.

In meantime I created a ticket in my internet provider system. Let's hope they will help me with this configuration.

If I would know that this device will be socomplicated to configure, then probably I would order another one.

If you willing to help me further with this configuration I can provide you the other screenshots, if that helps for something.

I followed your guide so I have most of the setings the same as you have.

New Member

Re: PAP2T Voip adapter - no ready line tone and no way to call o

I see from your port forwrding screen capture that you are also forwrdiing the range 50000-65535.

I also see from your first post, the link to Zyxel wiki, is illustrating to use RTP ports 50000-65535.

If this is true and your VoIP provider is recommending that you use RTP ports 50000-65535, then this may be the source of your problems with the PAP2T.

The PAP2T defaults to use RTP ports 16384-16538.   (most BYOD VoIP services default to use RTP range between 10000-20000.)

I note that you have forwarded this range in your router, as well as 50000-65535.

If your VoIP provider requires RTP 50000-65535, then I suggest you change the RTP Parameters Range Values in the PAP2T "SIP" settings Tab to be:

RTP Port Min:  50000

RTP Port Max:  65535

If this is indeed the source of your problems, then you no longer need to port forward the range values 16384-16538.

As well, if your RTP range is required to be 50000-65535, I'm not sure as to whether your Port Forward settings need to  be TCP or UDP, or both.  What does your VoIP provider recommend?

New Member

Re: PAP2T Voip adapter - no ready line tone and no way to call o

Zaxon, I also note another important point about your Port Forwarding.

According to your screen capture, your PAP2T is set to use DHCP IP address assignment (the Default).  This is fine, with the exception that your are Port Forwarding vs. Port Triggering.  Port Forwarding requires you to forward to a fixed IP address, which you have done.  However, because your PAP2T is accepting IP address assignment with DHCP, then it is possible that your PAP2T may work today with the changes recommended above.  But, if the Router assigns the PAP2T a different IP address some other day, then your Port Forwarding mapping will no longer be correct for the PAP2T new IP address assignment.

Thus, it may be prudent to use "Port Triggering" with DHCP assignments, vs Port Forwarding.

Otherwise, you may want to fix the IP address of the PAP2T to a Static Address that will not change unexpectedly.

You can set a static IP address on the PAP2T on the "System" Tab page.

I'm not famaliar with your Router, but, you may be able to set it to permanently assign the same specified IP address to the PAP2T permenantly.  If you can do that, you can still leave the PAP2T set for DHCP assignment and the Router will just always assign the same specified address to the PAP2T.

On my Linksys E3000, this is called "DHCP Reservation".  I often use this feature.

Otherwise, just use "Port Triggering" on the Router instead of Port Forwarding.

New Member

Re: PAP2T Voip adapter - no ready line tone and no way to call o

Zaxon, here is another tip that will be useful.

I note from your screen capture that the "Current Time" is not set on your PAP2T.

If you want your ATA to always have correct time, then you need to set it to use NTP Time Servers.

You can do this by clicking on the PAP2T's "System" Tab.

Then set the Primary and Secondary NTP Server values.

This is what I use on my device:

Primary NTP Server:  ""

Secondary NTP Server:  ""

However, you can set these values to any of the available world-wide NTP Time Servers.

New Member

Re: PAP2T Voip adapter - no ready line tone and no way to call o

Thanks Jeff for your suggestions.

For the port forwarding I change according to your info, but no luck. I'm not sure if this is a problem as I can see that the incomming call is received by the PAP2-T, but misteriously it is not pushed forward to the phone (also no tone when trying to make outgoing call). But when I try to use the phone to configure the PAP2-T then I'm gettin the voice response from the box.

For the port forwarding I reserved fixed IP allocation to the PAP2-T, so it will be always the same IP assigned. Then the port forwarding should work. I'm doing such things for my server and it keeps the settings.

For the current time I can use your suggestions, but I'm affraid this will not help me with the phone connection problems.

Anyway I created the ticket in my Internet provider system, so now I have to wait for their response (which usually is not so fast). For now I can use Skype credit to call outside, but the problem is that nobody will be able to call my home number.

I'm just bit dissapointed that this PAP2-T is so complicated and does not have any wizard for a simple Voip configurations as some of the adsl mosems with voip (like FritzBox or Zyxel modems I used before).

New Member

PAP2T Voip adapter - no ready line tone and no way to call or re

Sorry I haven't been able to help, Zaxon.

Generally, the PAP2T will work with its Factory Default settings. 

Typically, you only need to change your VoIP Provider's specific required registration settings. 

Typically, if registration settings are correct, then problems usually come down to port forwarding and NAT-Router Traversal issues.

I can only make a final suggestion that you confirm all the specific VoIP provider specific required settings.  Be sure to confirm the RTP port range supported by your provider and that the PAP2T is set to use RTP ports within that range.

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