Campbell Scientific Raven110 GPRS/EDGE Digital Cellular Modem - Manual (Page 35)

Appendix D. Understanding APNs
[Note: The following data is specific to the U.S. Cingular network; however, it
is applicable to any GSM network, although some of the APN names may have
a different name. Please check with your cellular carrier for specific IP
addressing options and details.]
GSM GPRS/EDGE cellular data networks use a mechanism called an APN
(Access Point Name) to determine how a Mobile Station (MS), in this case a
AirLink Raven, communicates via the GSM network to a host site (i.e., how
the carrier network passes IP traffic to the host). An APN determines what IP
addresses are assigned to the mobile station, what security methods are used,
and how the GSM data network connects to the customer’s network.
APNs are general-purpose and are available to multiple customers or can be
customized for particular customers to address unique requirements.
The various GSM providers all use APNs but implement them differently. For
example, some by default will not allow mobile terminated connections while
others use RADIUS servers and require user name/password authentication in
addition to SIM authentication.
Cingular provides multiple options for IP addressing, including public, private,
customer-supplied and network-assigned IP addresses. Various options are
available for static and dynamic IP addresses. Dynamic DNS naming is also
supported in certain APN types.
Cingular APN Types
Here we will focus on the AirLink Raven when used with the Cingular
network.
As stated above, the different GSM providers have varying APN types, so it is
important to check with your provider for available options.
Cingular offers four main APN types:
• Proxy
• Public
• Internet
• Custom
Proxy and Public APNs: These APN types are for outgoing, mobile originated
data only. No incoming, mobile terminate data connections are permitted. The
only difference in these two APN types are that proxy uses a Cingular provided
private IP address while public gets a public IP address.
Internet APN: The Internet APN allows incoming mobile terminated
connections as well as mobile originated. IP addresses are dynamic Internet,
Cingular-provided public addresses. An address maps to Dynamic DNS name
in the convention of 1[phone_number].internet.mycingular.com (e.g.
15055551212.internet.mycingular.com).
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