SBK-32 is a Remote SIM Bank with 32 sims that can connect with serial MV-37X via internet.
Connect with PORTech GSM Gateway via internet
SIM cards no longer need to be installed in GSM Gateway anymore;
You can deploy your VoIP GSM Gateway in different locations.
Centralize and supervise all SIMs in one place

MV-37X shipped out after Jun. 26, 2009 both can expand SBK-32.
P.S The label in the back of MV-37X mark “rs”
(MV-37X-CDMA version doesn't support remote SIM feature)

A non blocking switching system between MV-37X and SBK-32

SS-128: 128 sims SIM Server (manage 4 SBK-32 sim banks)
SS-256: 256 sims SIM Server (manage 8 SBK-32 sim banks)
SS-512: 512 sims SIM Server (manage 16 SBK-32 sim banks) 

Features:

A non blocking switching system between MV-37X and SBK-32 

SS-128: 128 sims SIM Server (manage 4 SBK-32 sim banks)
SS-256: 256 sims SIM Server (manage 8 SBK-32 sim banks)
SS-512: 512 sims SIM Server (manage 16 SBK-32 sim banks)

Features:

A non blocking switching system between MV-37X and SBK-32  

SS-128: 128 sims SIM Server (manage 4 SBK-32 sim banks)
SS-256: 256 sims SIM Server (manage 8 sim banks)
SS-512: 512 sims SIM Server (manage 16 sim banks)

Features: