Supported devices
ATA Adaptors
IP Phones
Cordless IP Phones
IP Conference Phones
IP PBX Software/Hardware
Desktop Softphones
Mobile Softphones

Security considerations for Callcentric customers

3CX Version 6
3CX Version 12
3CX Version 12.5
3CX Version 15
3CX Version 16
3CXPhone (for Windows)
3CXPhone (Mobile)
Aastra 6753i
Acrobits/Groundwire for iPhone
Android SIP Client
Apivio MWP1100
Asterisk 1.4 and 1.2
Asterisk 1.6
Asterisk 1.6.2, 1.8, and 10
Asterisk 14
Asterisk 17 CHAN_SIP (Vanilla)
Asterisk 17 PJSIP (Vanilla)
Asterisk Admin GUI v2.11
Asterisk Admin GUI v12
Asterisk Admin GUI v13
Asterisk Admin GUI v15
Bria Solo
Bria Desktop
Bria Mobile
Cisco ATA 186/188
Cisco SPA112/SPA122
CloudTC Glass 1000
D-Link DVG-1402S
Gigaset A510 IP
Gigaset C610A IP
Gigaset DX800A
Grandstream DP715/710
Grandstream DP750/720
Grandstream DP752/730/722
Grandstream GAC2500
Grandstream GRP2612
Grandstream GRP2613
Grandstream GRP2614
Grandstream GRP2615
Grandstream GXP1450
Grandstream GXP1620
Grandstream GXP1625
Grandstream GXP1630
Grandstream GXP1760
Grandstream GXP1782
Grandstream GXP2110
Grandstream GXP2130
Grandstream GXP2140
Grandstream GXP2160
Grandstream GXP2170
Grandstream GXP2200
Grandstream GXV3140
Grandstream GXV3240
Grandstream GXV3275
Grandstream GXV3370
Grandstream GXV3380
Grandstream HandyTone 286
Grandstream HandyTone 486
Grandstream HandyTone 702
Grandstream HandyTone HT802
Grandstream HandyTone HT814
Grandstream HandyTone HT818
Grandstream UCM6102
Grandstream UCM6204
Grandstream Wave Lite
Grandstream WP820
Htek UC803
Htek UC860
Htek UC924
Htek UC926
Innomedia SIP MTA-6328
Innomedia BuddyTalk 110
Linksys PAP2
Linksys SPA3102
Linphone Desktop (v4.1.1)
Linphone Desktop (v3.4.3)
Linphone Mobile
Linphone Mobile (v.3.2.3)
NCH Express Talk
Nokia E90
pbxnsip Version 3
Polycom SoundPoint IP 601
Polycom SoundStation IP 5000
snom 1xx/2xx/3xx
snom 820
snom D717
snom D735
snom D785
snom M9
snom ONE
Telco AC-211
trixbox / Elastix / pbx-in-a-flash
Windows Messenger
Unidata ICW1000G
Uniden EXP1240
UTStarcom F3000
Vodia PBX (v5)
Vodia PBX (v64.0)
VTech VCS754
VTech VDP650
VTech VSP600
VTech VSP725
VTech VSP726
VTech VSP735
VTech VSP736
X-Lite / X-Pro / eyeBeam
Yealink T32G
Yealink T41S
Yealink T42G
Yealink T42S
Yealink T46G
Yealink T46S
Yealink T48S
Yealink W52P
Yeastar MyPBX U100
ZoIPer 3.2
ZoIPer 5
ZoIPer Mobile
Zoom 5801
Zycoo CooVox U20
Other Linksys/Sipura products
Generic / Other Device

DID-Based Routing with Asterisk
Linksys PAP2

The Linksys PAP2 is a reliable inexpensive telephone adapter that works with the Callcentric service when placed behind your broadband internet router.

Most other Linksys and Sipura VoIP products (such as the SPA-xxxx series) are based on the same software as the Linksys PAP2; so you may also use the PAP2 setup guide to assist you with those products as well.

The information below is based on the PAP2 firmware version 3.1.3(LS); although most other older and newer versions will look very similar.

These instructions are based on using the PAP2 in its factory default configuration which is to obtain a dynamic IP address automatically from your router using DHCP, which is how most people have their home routers configured. For information on configuring your PAP2 with a static IP address, please refer to the PAP2 user manual.

We recommend that you read each step through in its entirety before performing the action indicated in the step.


Connect your router with the supplied Ethernet network cable to the PAP2. Now connect your phone to the PAP2 Line 1 port. Finally plug the supplied power cable into the PAP2.


Wait 60 seconds after plugging your PAP2 in.


Pickup the phone connected to the PAP2 and dial the * key on your phone 4 times.


Have a pen and paper ready. You will hear a message - "Configuration menu. Please enter option followed by the pound key...", then enter 1 1 0 # on your phone. You will now hear a message giving you the IP address of your PAP2 such as - " write this number down.


Open a web browser on your computer such as Internet Explorer and enter the IP address you heard in step 4 as the address (I.E. where you would normally enter
Please note: some browsers will require you to remove leading zero's ( 0 's ) in the IP address. For example if you heard "" you should change this to "".


Please note, the PAP2 by default does not have a password assigned to it, so you should now see a page that looks like this:

If you are prompted to enter the username and password please enter it and you should see the image above.


Now click on the "Admin Login" link as indicated in the picture below:


Now click on the "(switch to advanced view)" link as indicated in the picture below:


Click the tab labeled "System" in the menu at the top:


Enter time servers and DNS servers as indicated below:

  1. Set your Primary DNS server to a public DNS server such as You can also set your Secondary DNS server to a public DNS server such as

  2. Set your Primary NTP Server to, or your preferred working NTP server. You can also add a Secondary NTP Server if you wish

Click the "Save Settings" button after you have entered the time servers. The web page will display a screen for a few seconds stating that it is saving the changes you made.


Click on the SIP tab from the main menu.

Scroll down to SDP Payload Types section.

Set the following values:

RTP Packet Size: 0.020
G729a Codec Name: G729
G729b Codec Name: G729

Click the "Save Settings" button once you are done to save these changes.


Click the tab labeled "Regional" in the menu at the top. You will now be shown the Regional page. Scroll to the bottom of the Regional page. In the "Time Zone" field select the number of hours plus or minus that your local time is offset from Greenwich Mean Time (GMT).

Click the "Save Settings" button after you have selected the time zone.


Below we outline the steps assuming the use of Line 1.

Note: Now we will setup the line you will use Callcentric with. Normally if you are using the PAP2 only with Callcentric you would use Line 1 by clicking the "Line 1" tab which is how the example below is shown. If you already have another provider configured on Line 1, use Line 2 instead by clicking the "Line 2" tab. You may also configure Callcentric on both Line 1 and Line 2 by first setting up Line 1 following the directions below; and then repeating the step identically but in the "Line 2" tab.

Click the tab labeled "Line 1"


Within the Line 1 page is where most of the settings will be configured. Below is a list of the settings that need to be changed from the default configuration; you can click the screenshot below to see the full page of settings in detail.

NAT Mapping Enableyes
NAT Keep Alive Enableyes

ProxyEnter in this field
Outbound ProxyEnter in this field
Use Outbound Proxyyes
Use DNS SRVyes
DNS SRV Auto Prefixyes

User IDThis is either the default extension 1777MYCCID OR 1777MYCCIDEXT, where 1777MYCCID is the 1777 number assigned to you by Callcentric and EXT is the three digit extension you are trying to register this UA to.

For example: 17770001234101 would register to extension 101 on account 17770001234.

You cannot register to your account using only the extension number.
PasswordEnter your extension SIP Password here. Your extension SIP password is the password you created for the extension you are trying to use. You may edit the SIP password you wish to use in by logging into your My Callcentric account and clicking on the Extension menu link and then modifying the appropriate extension.
Auth IDThis is either the default extension 1777MYCCID OR 1777MYCCIDEXT, where 1777MYCCID is the 1777 number assigned to you by Callcentric and EXT is the three digit extension you are trying to register this UA to.

For example: 17770001234101 would register to extension 101 on account 17770001234.

You cannot register to your account using only the extension number.
Use Auth IDyes

Preferred CodecG711u
DTMF Tx MethodAuto

Within the Dial Plan delete ALL of the current setting and replace it with the following by copying the text below and pasting it into the Dial Plan field:

Click here to see the PAP2/Version 3 firmware picture
Click here to see the PAP2T/Version 5 firmware picture

Click the "Save Settings" button after you have finished entering all information on the Line 1 page.


At this point your PAP2 should be registered (connected) to our servers. You can verify that your PAP2 is successfully setup in ANY of the following ways:

  • Click the "Info" tab in the top menu. Under the "Line 1 Status" section on the Info page you should see "Online" next to the "Registration State" field.
  • The light next to the Line 1 on the front of your PAP should be on.
  • You should have dial tone on Line 1 when you pickup the phone.
If you do not see your PAP2 as registered, you should re-verify all steps in the setup process above. Make sure you have entered all settings correctly.


That's it! You can now make a phone call.

You can make a test call to 17771234567, or if you are signed up for one of Callcentric's rate plans you can place a call to a traditional landline or mobile phone by dialing either:
1 + the area code and number for calls to the US
011 + the country code, area code, and number for calls worldwide (you may also use 00 instead of 011).