The first step is to find out what IP Address your adapter is currently using. To do this, pick a phone connected on Line 1 and do the following:
Dial: **** (That is 4 asterisks)
Once this is done, dial: 110# (110 followed by a square)
The system should now playback the IP Address your device has been assigned.
Using your favorite web browser from a computer on the same network, point the address to the IP address of your adapter.
(example http://192.168.1.2) Replace 192.168.1.2 by the IP Address your device is currently using.
You should now see the web interface of your Linksys/Sipura.
click on the link "Admin", and once the page has reloaded, click again on the link "Advanced View".
Under the LINE 1 Tab, Find the following fields and fill them with the following information
Nat Keep Alive: Yes
Nat Mapping/Traversal: Yes
Register Expires: 180
Proxy Fallback Intvl: 180
Display Name: Bill Smith (Replace with your name or company name)
User ID: 102669-0000 (Replace with your account number)
Password: ******** (Enter your account password)
Use DNS SRV: NO
DNS SRV Auto Prefix: NO
Optionally, To save bandwidth, you can change Line 1 "Preferred Codec" to G729a and make sure "Use Pref Codec Only" is set to no.
Optionally, you can configure your adapter with a better dial plan, allowing faster dialing of 10 digits number (Local US/Canada) and also enable 7 digits dialing in one area code of your choice.
At the bottom of Line 1 TAB, you will find a field called Dial Plan
Replace the 555 digits in the following line by the area code of your choice and copy the line, including parenthesis, in the Dial plan field in Line 1 Tab at the bottom of the page:
Swith to the SIP tab and scroll down to RTP Parameters and set the follow setting:
RTP Packet Size: 0.020
Click on the "Save Settings" button at the bottom of the form.