The
service allows you to check the voice mail not being by the phone or computer where the mail
comes. All one has to do is dial a special number (usually given by the
communication provider) and listen to voice mails.
By using Portech SBK-32 expander for 32 SIM-cards, you can increase the number of channels in the Portech MV-37X GSM VoIP gateway series using the Internet.