Common Administrative Tasks
This section describes administrative tasks that are common to both Diameter and RADIUS Remote Network Elements.
To navigate to the Remote Network Elements dialog select Remote Network Elements, and then select either Diameter Elements or RADIUS Elements. The main dialog for Diameter Remote Network Elements is shown in Figure 37.
- Add a New Diameter or RADIUS Remote Network Element.
- Edit an Diameter or RADIUS Remote Network Element.
- Delete an existing Diameter or RADIUS Remote Network Element.
- Refresh the list of Diameter or RADIUS Remote Network Elements.
Creating and Naming a Diameter or RADIUS Remote Network Element
To create a new Diameter or RADIUS Remote Network Element:
- Click New from the main Diameter or RADIUS Network Elements dialog.
- Enter the name by which others will refer to this network element in the Name field.
- Optionally, enter a description for the network element in the Description field. The description you associate with a network element is not used during processing.
Editing a Diameter or RADIUS Remote Network Element Description
To edit the description of a Diameter or RADIUS Network Element:
- From the main Diameter Network Elements dialog (Figure 37), select the Remote Network Element you want to edit and click Edit.
- Edit the Description field by highlighting the entire field and typing in the new description.
- Click OK to save the edited description.
Deleting a Diameter or RADIUS Remote Network Element
- From the main Diameter Network Elements or RADIUS Network Elements dialog, select the Network Element you want to delete and click Delete.
You are prompted with a Confirm Delete dialog.
Assigning Functions and Configuring Implicit Routing Rules
This section describes how to assign functions to a Diameter or RADIUS Remote Network Element. Certain functions require you to configure implicit routing rules when you assign the function to the network element. This section also provides an overview of the implicit routing rules.
Functions Supported in the IMS AAA Server
Table 16 provides a description of each functions supported by the IMS AAA Server and specifies whether the function is supported in Diameter, RADIUS, or both.
The WLAN Access Network function is a source of authentication, authorization and accounting for the Direct IP service provided by the WLAN infrastructure.
This function is assigned to other 3GPP AAA servers to which this server may forward (proxy) requests.
For example, the HSS may indicate the request needs to be redirected to another 3GPP AAA Server; in which case the local IMS AAA Server must proxy the request to the remote 3GPP AAA server. This remote 3GPP server would be assigned the Downstream function. Another example would be when a subscriber's identity or realm decoration indicates roaming, and the IMS AAA Server may need to proxy the request to another 3GPP AAA server outside the HPLMN.
The Home Subscriber Server is a Diameter-based subscriber and policy database used in 3GPP networks that implement IMS R6 or later. The IMS AAA Server downloads and caches both user credentials and service subscription data (profile data) from the HSS. In addition, the IMS AAA Server coordinates with other 3GPP AAA servers via a registration mechanism in the HSS. The first 3GPP AAA server that authenticates a particular subscriber is registered as the "responsible" server in the HSS. Any subsequent authentications for that subscriber will be redirected to the "responsible" server, as long as it remains registered. After the subscriber has left the network, the registration may be purged by the 3GPP AAA server or the HSS, meaning it is no longer responsible and the next server to authenticate this subscriber may take over. The reference point between IMS AAA Server (3GPP AAA server), and the HSS is Wx, and it is defined only in terms of Diameter. Hence, the HSS function is not available for RADIUS network elements.
The Packet Data Gateway performs authentications and authorizations of tunnel requests, when tunneled IP service (3GPP IP Service) is being provided. The authorization processing of these requests is different from requests received from WLAN AN devices, because a different 3GPP service is used. However, the rest of the processing is very similar to WLAN AN. This function exists only for Diameter network elements, because no RADIUS protocol binding for the reference point (Wm) is defined.
The Charging Data Function is the accounting server for offline charging. Also known as Charging Collection Function, this function receives all chargeable event records from the IMS AAA Server and other network elements.
The Upstream function represents another 3GPP AAA Server, such as another Juniper IMS AAA Server, or other vendor's AAA server, communicating over the Diameter protocol. This server proxies, or redirects requests to this local IMS AAA Server.
These requests may be of the form usually received from WLAN AN or PDG in the local network, but they are actually proxied from some remote network. In this scenario, the exact WLAN AN or PDG the request originated from might not be known to this local IMS AAA Server.
For example, if a roaming subscriber is receiving the 3GPP IP service provided by a visited network, the VPLMN might proxy the authentication received from the PDG to the HPLMN's IMS AAA Server. The IMS AAA Server in the HPLMN would not know the actual PDG, but it would still be expected to authorize the access (roaming access in this case).
This function is assigned to AAA servers that are operating in a cluster with the local server. The local server may forward requests to this AAA server, if the peer can process the request more efficiently.
The WLAN Access Gateway implements an enforcement function. During authorization, the IMS AAA Server pushes routing policy information for the subscriber's current service to the WAG, which will then enforce this routing policy.
This is only used for WLAN 3GPP (tunneled) IP Access service.
Policy server sending service activation and deactivation requests. See Enabling Dynamic Authorization for Routers for more information.
To assign functions to a Diameter or RADIUS Remote Network Element, select the function from the predefined list in the IMS AAA Server Administrator. Most functions require no further configuration. However, certain functions require you to configure implicit routing rules when you assign the function. For instance, when you assign the HSS function to a Diameter Remote Network Element, you need to specify which subscribers are served by the HSS. This is done by assigning the HSS function and configuring the implicit routing in the function configuration.
NOTE: You can configure only one element of the SRC network for the SRC function.
NOTE: If you assigned the SRC function, the server does not start listening for incoming RADIUS request until you establish at least one SRC connection in a network element.
Implicit Routing Rules
Implicit routing is based on subscriber identity or realm, except for the WAG function. In 3GPP WLAN networks, the subscriber identity is the IMSI (International Mobile Subscriber Identity) of the mobile device.
Table 17 shows the functions that use implicit routing rules, and the type of routing rules used by each function.
IMSI Prefix Routing-Allows you to specify which IMSI prefix numbers are associated with the remote peer (function). For example, entering 3000 for the IMSI prefix routing for an HSS, instructs the IMS AAA Server to use this HSS for all requests that have an IMSI beginning with 3000. Optionally, you can instruct the server to route all local subscribers to this HSS by selecting the Default route for all local users option.
Realm Routing-Allows you to specify which realms are routed to the remote peer (function). When a request is received, the server examines the NAI decoration to determine the realm to which the request should be routed. If the request does not contain an NAI decoration, the Destination-Realm in the request is used; this applies to Diameter requests only. For example, if you entered XYZ.com under the realm routing rule for an HSS function, the IMS AAA Server would retrieve subscriber credentials from this HSS for processing any requests with an NAI decoration that includes XYZ.com. Optionally, you could use the HSS for processing all requests from all realms by selecting the Default route for all users from all realms option.
Origin-Host Routing-(Used for WAG function only) Allows you to specify which PDG's Origin-Host names have their requests routed to the remote peer. Optionally, requests from any PDG's Origin-Host can be routed to the remote peer by selecting the Default route for all origin host option.
Origin-Realm Routing-(Used for WAG function only) Allows you to specify which PDG's Origin-Realm names have their requests routed to the remote peer. Optionally, requests from any PDG's Origin-Realm can be routed to the remote peer by selecting the Default route for all origin realm option.
Implicit Routing Rule Priorities
The server uses the following priorities to process implicit routing rules:
- IMSI
- Realm
- Default IMSI route (default route for local users)
- Default Realm route (default route for all users from all realms)
For example, if both IMSI and realm routing rules are defined for the function, IMSI routing rules take priority over realm routing rules.
NOTE: Any Explicit routing rules defined for a function, take priority over Implicit routing rules.
For more information on routing rules see Request Routing Rules.
Assigning Functions to a Remote Network Element
To assign a function to a Diameter or RADIUS Remote Network Element:
- From the main Diameter or RADIUS Network Element dialog, click New next to the Functions Assigned list.
The server displays the list of functions supported by the Diameter or RADIUS Network Element. Figure 38 shows a sample dialog for Diameter Network Elements.
A dialog opens that displays a brief description of the function and a Description field. If the function supports implicit routing, the respective configuration tabs will also be shown in the dialog. Figure 39 shows an example dialog for the HSS function.
For functions that do not support implicit routing, proceed to step 3. For functions that do support implicit routing proceed to Configuring Implicit Routing Rules.
The function is added to the Functions Assigned list.
Configuring Implicit Routing Rules
The following section describes how to configure the various types of implicit routing rules including:
- Configuring IMSI Routing Rules
- Configuring Realm Routing Rules
- Configuring Origin-Host Routing Rules (WAG Function only)
- Configuring Origin-Realm Routing Rules (WAG Function only)
Configuring IMSI Routing Rules
To configure IMSI Routing rules:
The New IMSI Prefix Routing Rule dialog is displayed (Figure 40).
- Select the Default route for local users option. This option specifies that all local subscribers use this function. If you select this option, proceed to step 3.
The IMSI prefix is added to the list of IMSI prefixes.
The function is added to the Functions Assigned list.
Configuring Realm Routing Rules
To configure Realm Routing rules:
The New Realm Routing Rule dialog opens (Figure 41).
- Select the Default route for all users from all realms option. This option specifies that requests from all realms be routed to the remote peer. If you select this option, proceed to step 3.
The realm name is added to the list of Realms.
The function is added to the Functions Assigned list.
Configuring Origin-Host Routing Rules (WAG Function only)
If you selected the WAG function, use the following steps to configure the Origin-Host routing rules:
The New Origin-Host Routing Rule dialog opens (Figure 42).
- Select the Default routing rule for all Origin-Host option. This option specifies that requests from any Origin-Host be routed to the remote function. If you select this option, proceed to step 3.
The Origin-Host is added to the list of Origin-Hosts.
The function is added to the Functions Assigned list.
Configuring Origin-Realm Routing Rules (WAG Function only)
If you selected the WAG function, use the following steps to configure the Origin-Realm routing rules:
The New Origin-Realm Routing Rule dialog opens (Figure 43).
- Select the Default routing rule for all Origin-Realm option. This option specifies that requests from any realm be routed to the remote function. If you select this option, proceed to step 3.
The Origin-Realm is added to the list of Origin-Realms.
The function is added to the Functions Assigned list.
Editing Functions and Implicit Routing Rules
- From the main Diameter Network Elements or RADIUS Network Elements dialog, select the Remote Network Element you want to edit and click Edit.
- Select the function from the Functions Assigned list and click Edit.
The edit dialog for the particular function opens.
- Make the desired changes by following the steps in Assigning Functions and Configuring Implicit Routing Rules.
- Click OK to save the edited function.
- Click OK to save the Remote Network Element.
Deleting a Function from a Diameter or RADIUS Remote Network Element