Specifications

Sierra Wireless, Inc. CDPD Primer
2130006 Rev 1.0 Page 19
4.2.4. Network Management Services
Network Management Services are administrative services for the network provider itself, and
do not involve the subscriber. They include:
• Configuration Management of the various components of the CDPD network, which includes
collecting data from and sending data to them, as well as controlling them remotely.
• Fault Management to detect, isolate, and correct, abnormal operations in any portion of the
CDPD network.
• Performance Management to evaluate and report the behavior and effectiveness of the
telecommunications equipment making up the CDPD network.
• Security Management to detect and prevent access to the network and the network
management resources by unauthorized subscribers.
4.2.5. Accounting Services
Accounting Services provide information to the CDPD service providers about how the CDPD
network resources are being used. They maintain statistics about the Protocol Data Units (PDUs)
sent across the network—packets successfully transferred by users through the network.
Accounting Services permit CDPD carriers to know how their systems are being used, and how
much to charge their customers.
4.2.6. Authentication Services
Authentication Services verify that subscribers accessing a CDPD network are who they say they
are. CDPD modems must be registered on the CDPD network before communication can begin
(see section 5.1 for more detail). The registration process involves an exchange of identification,
authentication, encryption key, and sleep characteristic information. Modems can be set to
register manually (on command) or automatically when they start or reset, but they generally
register automatically. Using the Diffie-Hellman Electronic Key Exchange mechanism,
credentials maintained by the CDPD subscriber’s modem are checked against authentication
information maintained in a CDPD Authentication Center. These credentials are updated by the
CDPD Network Operations Center on a regular basis to provide additional security.
4.2.7. Encryption Services
Encryption Services encrypt data transferred between the M-ES and the MD-IS—but not any
other portion of the network—using RSA RC-4 encryption, and managed by the Subnetwork-
Dependent Convergence Protocol (SNDCP), which is discussed in section 5.3. If necessary, the
carrier or end user may encrypt data traveling over other portions of the network using other
mechanisms.
4.3. Logical: CDPD Protocols
The basic structure of the CDPD network communications is based on the International
Standards Organization (ISO) layered communications reference model. Using this layering
technique, communication between application processes can be viewed as being logically
partitioned into an ordered set of layers in a stack (known as a protocol stack).