Using PAP2T over Skinny Broadband to 2Talk

Despite what we were all thinking, the PAP2T-NA will work in the Skinny Broadband Double-NAT scenario & 2Talk.

The PAP2T is still widely available due to aged stock or clone and there are even 2Talk re-sellers touting these on Trademe
As I type this reply my Geekzone page is surrounded by PAP2T adverts - thanks to Google Analytics no doubt!
I paid $30 for my unit from Trademe and checked the authenticity of it using this site -> voipfan.net/other/fakepap2.php

This is how I got mine to work...

Skinny Modem:
1. Skinny Broadband Modem (default settings as delivered). Model B315s-608.
2. Settings/Security/SIP ALG Settings: turn off (not enabled). It will still seemingly work with this enabled but common
advice is to avoid using this feature unless you need to.

PAP2T-NA
The PAP2T-NA has additional NAT Support Parameters (VIA) that seem to manage/modify the SIP header by handling the double
NAT IP addresses. Hard to find much info on these and not all providers support this but luckily 2Talk do.

1. To save time I used the 2Talk Auto-Provisioning wizard for the initial configuration settings as this ensures the basics
such as account info, Regional Settings etc are correct.
2. Then set the Following:

[SIP]
admin/advanced/sip

Nat Support Parameters

Handle VIA received = Yes
Insert VIA received = Yes
Substitute VIA Addr = Yes
Handle VIA rport = Yes
Insert VIA rport = Yes
Send Resp To Src Port = Yes

2Talk advised I need to set "registration expiry/interval short due to the double NAT" but were non specific so I have
abritarily set these for now as follows:

NAT Support Parameters-> NAT Keep Alive Intvl: 15
SIP Timer Values (sec)-> Reg Max Expires:180

----------------------------

[Line 1]
admin/advanced/Line1

SIP Settings
SIP Port:50600

Proxy and Registration
Proxy:plus.2talk.co.nz:50600
Outbound Proxy:plus.2talk.co.nz:50600
(note that the SP Port 50600 needs to be added to the proxy address)

Observations & tweaks:

No need for stun server settings in the PAP2T or any port allocations Modem makes this a simpler solution.

I prefer to use Fixed IP addresses for devices on my network like Printers & PAP2T's.
By Default the Skinny Modem uses DHCP 192.168.1.65 -> 253.
I set my PAP2T to 192.168.1.10 (adjust to suit) which makes it easier to manage.
You can do this prior to initial config using the IVR method or alter once you log on via the browswer...

admin/advanced/System

Internet Connection Type
DHCP: no
Static IP: 192.168.1.xx (xx = 10 in my case)
Gateway: 192.168.1.254 (Skinny Modem address)
NetMask: 255.255.255.0

Optional Network Configuration
Primary DNS: 192.168.1.254 (Skinny Modem address)

If things go wonky one day you can at least try a remote reboot via your browser ->192.168.1.xx/admin/reboot
I found this quite good after setting parameters as the PAP2T didn't always reboot after changes were made.

TEST:
If you reboot the Skinny Modem it will generally be allocated new IP addresses. After a power reset of the Modem the
WhatsMyIP website reported a new 122.xxx.xxx.xxx Public address and the Modem WAN had a new 100.xxx.xxx.xxx address
(Settings/Device Information/WAN IP Address).
The PAP2T re-connects as soon as the Skinny Modem connects which is a good
sign that it is managing things OK thus far.

TIME:
I had issues with the time setting. Even using the same NTP setting as the Skinny Modem the PAP2T was an hour out
regardless of the daylight saving rule. This needs to be correct as the likes of my Panasonic cordeless syncs it's clock
off the Caller-ID between the 1st & 2nd ring with every call. Looks like the PAP2T formats the Caller ID from the incoming
call data (name & Number) and the Local time on the PAP2T.

admin/advanced/System
Primary NTP Server: ntp.2talk.co.nz

My hope is that this will still work when daylight saving rolls over. Time will tell...

GlenzAGeek

GlenzAGeek