Title: SPA400 Compatibility with PBX Systems
Article ID: 3910
The SPA400 Internet Telephony Gateway is designed to work only with the SPA9000 IP PBX and the Linksys Voice System. It will not support any other platforms (such as Asterisk®).
But in fact, it is not difficult to make it work with asterisk
You may consider to buy OBi110 at HKD399 since it contains two SIP Client such that you are able to register HKBN 2b and CMPhone without any problems. For other other account, you could make outgoing calls only.
Or get a good second hand SPA3000 from Taobao, or buy a SPA3102 from 雯雯 if she has spare. Then make use of both sip account for 2b +/- cmphone or 12voip. Put voip into one of the gateway account to use on the fly
I think your 12voip is outgoing only and for you to do IDD.
Of course if you need US call, OBi110 is much better because you can have a GV account registered in one of the sip accounts.