Open a browser window and type in this address:
http://IP_address/admin/advanced
(using the IP address from step 4).
The settings you need to edit or check are as follows:

- Display name: Your name as you want it to appear on the phone
- User ID: The Username/user id (should be 8 digits) in your welcome email
- Password: The password in your welcome email
- Use Auth Id: Ticked
- Auth ID: he Username/user id (should be 8 digits) in your welcome email
- Mini certificate Leave blank
- SRTP Private Key Leave blank
In the proxy and registration section:
- Proxy: Set this to the proxy domain to the registration server name you will have been advised to use in your welcome email (this will look like sip.freevirtualnumbers.co.uk or lon-pbx-X.freevirtualnumbers.co.uk).
- Use Outbound proxy: Yes
- Outbound proxy: Set this to the Outbound proxy server name you will have been advised to use in your welcome email - this will look like nat.freevirtualnumbers.co.uk:5082
- Use OB proxy in Dialog: Yes
- Register: Yes
- Make call without reg: No
By Default we support the G711a or G711u Codecs but if you are using multiple phones on your broadband connection, or you have a low bandwidth internet connection, then in the Audio Configuration section we recommend you choose G729a as the Preferred Codec. This will allow the phone to use less bandwidth where possible.
Please note that if you wish to use G729a you will need to request that this codec is enabled for your extension via the control panel.
Please set your DTMF Tx Method to AUTO this will allow our system to recognise what keys you press on your phone.

- Preferred codec G711u
- Silence Supp Enable no
- Use pref codec only yes
- Silence Threshold medium
- G729a Enable yes
- Echo Canc Enable yes
- G723 Enable yes
- Echo Canc Adapt yes
- G726-16 Enable yes
- Echo Supp Enable yes
- G726-24 Enable yes
- Fax Ced Detect Enable yes
- G726-32Enable yes
- Fax CNG Detect Enable yes
- G726-40 Enable yes
- Fax passthru Codec G711u
- Fax Code Symmetric yes
- Fax passthru method NSE
- DTMF Tx Method auto
- Fax Process NSE yes
- Hook Flash Tx Method None
- Fax disable ECAN no
- Release unused codec yes
If you intend to use multiple Linksys Adaptors behind a Nat Firewall you will need to give each port on the Adaptor a unique SIP Port number.

For example if you have two Telephones and you wish to use all four lines then on the first Telephone you would set ext1 sip port to 5060 and ext2 sip port to 5061, on the second Telephone you would set ext1 sip port to 5062 and ext2 sip port to 5063.