Appendix K: Peer-To-Peer Cellular Data Service - US Robotics USR3520 User Manual

Appendix K: Peer-To-Peer Cellular Data Service

Conventional cellular data service routes connections from a mobile device to the Internet, illustrated
below. The Modemulator can use this type of data service only when operating in single-ended mode to
make mobile-originated connections.
In order to emulate the PSTN, the Modemulator requires a special type of cellular data service when
operating in the default peer-to-peer mode that doesn't route connections to or through the Internet. The
Modemulator requires service that allows connection from one mobile device to another mobile device.
This type of peer-to-peer data service is typically not available directly from mobile operators. However,
Mobile Virtual Network Operators (MVNOs) can provide this type of service, illustrated below.
With this type of peer-to-peer data routing, each of the mobile devices are assigned a private, static IP
address. An originating Modemulator can contact an answering Modemulator by addressing the IP address
of the answering Modemulator. The IP addresses are routable only within the MVNO private network, and
are not reachable by any outside networks.
When engaging with an MVNO to provide cellular data service for Modemulator, be sure to specify this
type of peer-to-peer data routing. Also be sure to ask the MVNO about any restrictions in connectivity
between devices or between different cellular networks.
Modemulator User Guide
Cellular
Data Network
Firewall
Cellular
Data Network
MVNO
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