My SAP2102-R Voip adapter is not working. Can I buy any VoIP adapter from inernet and make it work?

Not all VoIP services provide free VoIP ATA adapapters.
In which case you are responsible to pay for replacement. But, without knowing who your VSP (VoIP service provider) is, I can only assume they do not supply for free.

I personally only subscribe to BYOD (bring your own device) VoIP providers. Thus, I always buy my own “unlocked” ATA (analog telephone adapter) and am responsible for the operation and configuration of my ATA.

If your VSP provided the old ATA to you, it may be “pre-provisioned” and “locked” to their service. Many of these same VSP’s do not allow people to BYOD or provision your own ATA. In which case, it would not do you any good to buy your own “unlocked” ATA. As you cannot connect to their service unless you know how to set the VoIP server and proxy server, codecs, etc. that the VSP does not publicly disclose.

I use BYOD VoIP services like CallCentric, InPhonex, Les.net, and Voip.ms. These are open SIP (Session Initiation Protocol) providers. Any VSP that is BYOD is usually SIP-based. And, all Linksys ATA’s are designed to work with SIP.

I use the Linksys PAP2T-NA 2-line ATA behind a Linksys WRT-54G Router. However, next time around I plan on getting the Linksys SPA-2102-NA, as they have the built-in Router, which I belive is more user friendly for VoIP port forwarding and QOS settings. It is a little more complicated when using a separate NAT-Router in front of the PAP2T-NA.

Where to buy:

I bought my ATA’s from VoIP Depot in Canada:
http://www.voipdepot.ca/index.php?main_page=product_info&cPath=1&products_id=79
But, they only ship within Canada.

In USA:
Voip Supply:
http://www.voipsupply.com/product_info.php?manufacturers_id=36&products_id=1663
NCIXUS:
http://www.ncixus.com/products/23864/SPA2102-NA/CISCO/
Voip Link:
http://www.voiplink.com/Linksys_SPA_2102_p/linksys-spa-2102.htm
Buy.com
http://www.buy.com/prod/voip-router-2-fxs-2-rj45-t-38-perp/q/loc/101/202672436.html

I configure my ATA for CallCentric on Line-1, and InPhonex on Line-2. Both VSP’s post the configuration information you need on their web sites for configuring Linksys products. They are BYOD, no contracts, no obligations, only pay-as-you-go.