Linksys (Cisco) VoIP set audio interface-a table

Rt41p2 2fxs 4eth
Rt31p2 2fxs 3eth

Rt3002fxs 4 + 1eth

Pap2t 2fxs 1eth 10 Mbps
PAP2T-NA 2fxs 1eth

PAP2-NA

Pap2 V2 2fxs
This product supports t38 protocol high-speed Fax
 
It is great for users who need to fax in China. Products prior to V2, PAP2-NA, pap2t do not support t38 Protocol
(PAP2-NA, pap2t only supports SIP-based fax. There is still no way to send and receive faxes in China .)
Pap2 V2, which supports t38 protocol fax, is tested by multiple carriers with a sending rate of 100%.
No setup is required, as long as the carrier supports sending and receiving faxes.

Spa400 4fxo 1eth
Spa1001 1fxs 1eth
Spa2102 2fxs 2eth

Spa3000 1fxs 1fxo 1eth
Spa3102 1fxs 1fxo 1eth, same as spa3000 but with rout function (VOIP to PSTN and PSTN to VoIP)

Spa8000 8fxs 1pbx (RJ-21) 1eth 100 Mbps
Spa9000 2fxs 1 + 1eth

WRT54GP2A-AT 2fxs 4 + 1eth 1wl (802.11g) // a really bad Router