Simple IP and Mobile IP in a Single System Configuration Example


Simple IP and Mobile IP in a Single System Configuration Example
 
 
This chapter provides information for several configuration examples that can be implemented on the system to support Simple IP and Mobile IP data services in a single system.
Important: This chapter does not discuss the configuration of the localout-of-band management context. Information about the localout-of-band management context can be found in Chapter 1 of Command Line Reference. Additionally, when configuring Mobile IP take into account the MIP timing considerations discussed in the section MIP Timer Considerations�.
 
Using the System as Both a PDSN/FA and an HA
The system supports both Simple and Mobile IP. For Mobile IP applications, the system can be configured to perform the function of a Packet Data Service Node/Foreign Agent (PDSN/FA) and/or a Home Agent (HA). This example describes what is needed and how a single system simultaneously supports both of these functions.
In order to support PDSN, FA, and HA functionality, the system must be configured with at least one source context and at least two destination contexts as shown in the following figure.
The source context will facilitate the PDSN service(s), and the R-P interfaces. The AAA context will be configured to provide foreign/home AAA functionality for subscriber sessions and facilitate the AAA interfaces.
The Mobile IP destination context will be configured to facilitate the FA service, the HA service and the PDN interfaces for Mobile IP data services. The Simple IP destination context will facilitate the PDN interfaces for Simple IP data Services.
In addition to the source and destination contexts, there are additional system-level AAA parameters that must be configured.
sipmip_cfg_ex_1a.wmf
Simple and Mobile IP Support Within a Single System
 
Information Required
Prior to configuring the system as shown in this example, there is a minimum amount of information required. The following sections describe the required information to configure the source and destination contexts.
 
Source Context Configuration
The following table lists the information that is required to configure the source context.
Required Information for Source Context Configuration
NOTE: For this configuration, the IP context name should be identical to the name of the destination context.
 
AAA Context Configuration
The following table lists the information that is required to configure the AAA context.
Required Information for AAA Context Configuration
 
Mobile IP Destination Context Configuration
The following table lists the information that is required to configure the destination context.
Required Information for Destination Context Configuration
NOTE: For this configuration, the destination context name should not match the domain name of a specific domain. It should, however, match the name of the context in which the HA service is configured if a separate system is used to provide HA functionality.
NOTE: The system will only support multiple Mobile IP sessions per subscriber if the subscriber’s mobile node has a static IP address.
Never require authentication (NOTE: the initial registration and de-registration will still be handled normally)
NOTE: For this configuration, the IP context name should be identical to the name of the destination context.
 
Simple IP Destination Context
The following table lists the information that is required to configure the optional destination context. As discussed previously, This context is only required if Reverse Tunneling is disabled in the FA service.
Required Information for Destination Context Configuration
NOTE: For this configuration, the destination context name should not match the domain name of a specific domain.
 
System-Level AAA Parameter Configuration
The following table lists the information that is required to configure the system-level AAA parameters.
Required Information for System-Level AAA Configuration
NOTE: The default domain name can be the same as the source context.
NOTE: The last-resort context name can be the same as the source context.
NOTE: The username string is searched from right to left for the separator character. Therefore, if there is one or more separator characters in the string , only the first one that is recognized is considered the actual separator. For example, if the default username format was used, then for the username string user1@enterprise@isp1, the system resolves to the username user1@enterprise with domain isp1.
 
How This Configuration Works
The following figure and the text that follows describe how this configuration with a single source and destination context would be used by the system to process a Simple IP data call.
Call Processing When Using the System as a PDSN, FA, and HA
In this example, Subscriber1 is establishing a Simple IP data session, while Subscriber2 is establishing a Mobile IP data session.
 
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Sessions for Subscriber1 and Subscriber2 are received by the PDSN service over the R-P interface from the PCF.
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For this configuration, the result of this process for both Subscriber1 and Subscriber2 would be that the system determines that AAA functionality should be provided by the AAA context.
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The system would then communicate with the AAA server specified in the AAA context’s AAA configuration to authenticate the subscribers.
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Subscriber1: The system will go through the process of determining which destination context to use for the subscriber session. This process is described in the How the System Selects Contexts section located in the Understanding the System Operation and Configuration chapter of the System Administration Guide. For this configuration, the system determines that the egress context is the SIP Destination context based on the configuration of the Default subscriber in the Source context.
Subscriber2: The system uses the Mobile IP FA context name configured within the PDSN service to determine what destination context facilitates the FA service. In this example, it determines that it must use the MIP Destination context and it passes the HA IP address to the FA service.
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For Subscriber1’s session, data traffic would then be routed through the PDN interface in the SIP Destination context.
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For Subscriber2, the FA service then establishes a connection to the specified HA service through the ICC interface.
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For Subscriber2, the system would then communicate with the AAA server specified in the AAA context’s AAA configuration to authenticate the subscriber.
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For Subscriber2, upon successful authentication, the MIP Destination context determines which destination context to use for the session and Mobile IP registration would be completed. This process is described in the How the System Selects Contexts section located in the Understanding the System Operation and Configuration chapter of the System Administration Guide.
For this example, the Source context determines that the egress context is the MIP Destination context based on the configuration of the Default subscriber.
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For Subscriber2’s session, data traffic would then be routed through the PDN interface in the MIP Destination context.
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