Oracle® Communications Diameter Signaling Router Equipment Identity Register (EIR) User's Guide Release 8.3 E93573 |
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When a handset roams into a new MSC/VLR area, it attempts a registration procedure with the VLR. In a network without the EIR function, this procedure results in the VLR sending a location update message to the HLR providing the HLR with the current MSC location of the Mobile Station (MS)/handset. When the EIR function is deployed in a network, this registration procedure is interrupted to validate the IMEI of the MS/handset attempting to register before completing the registration procedure and updating the HLR.
In the network with EIR, the MSC/VLR sends a MAP_CHECK_IMEI message to DSR requesting EIR processing before sending a location update to HLR. This message contains, at a minimum, the IMEI of the MS attempting registration. It may also contain the IMSI of the subscriber whose SIM card is currently being used in the MS/ handset. Upon receipt of this message, EIR searches the White, Gray, and Black Lists for a match on the IMEI. EIR then returns a response to the MSC. Depending upon the result of the search, the response contains either the equipment status of the MS/handset (whether the IMEI for the MS/handset is allowed or not based on its status in the White, Gray, or Black Lists), or a user error (invalid or unknown IMEI). The MSC then either continues the registration procedure (if the IMEI is allowed) or rejects it (if the IMEI is disallowed, invalid, or unknown).
If the IMSI is also included in the message, EIR attempts to match this IMSI to one provisioned with the IMEI before sending a response to the MSC. A match on IMSI overrides any Blacklist condition found based on the IMEI match alone and causes a response of MS allowed.
Figure 2-1 vSTP EIR Call Flow
The UDR information contains the list of IMEIs and an indication to the list where they are located. UDR contains two types of IMEIs: Individual IMEIs (GUID-02BBA66B-F3BE-4E21-B933-54A51DEAEE8C.htm#GUID-02BBA66B-F3BE-4E21-B933-54A51DEAEE8C__TABLE_4BE7F1C183E246C892DD5100A075339A) and ranges of IMEIs (GUID-02BBA66B-F3BE-4E21-B933-54A51DEAEE8C.htm#GUID-02BBA66B-F3BE-4E21-B933-54A51DEAEE8C__TABLE_2EB45F8E383F4D3384EB5AFAF2B0F4DE). The Individual IMEIs are searched first. The IMEI entries in this list may also contain an association to an IMSI. If no individual IMEI match is found, IMEI ranges are searched.
EIR can support up to 100 million subscriber entries, including both individual IMEI and a range of IMEIs.
Table 2-1 Example of Individual IMEIs
IMEI | IMSI (optional) | White List | Gray List | Black List |
---|---|---|---|---|
12345678901234 | 495867256894125 | No | No | Yes |
234567890123456 | No | Yes | No | |
49876523576823 | No | Yes | Yes | |
68495868392048 | 495867565874236 | Yes | Yes | No |
29385572695759 | Yes | Yes | Yes |
As shown in GUID-02BBA66B-F3BE-4E21-B933-54A51DEAEE8C.htm#GUID-02BBA66B-F3BE-4E21-B933-54A51DEAEE8C__TABLE_4BE7F1C183E246C892DD5100A075339A, it is possible for a given IMEI to be on more than one list (on the Whitelist, and also on the Gray and/or Black List). The logic illustrated by GUID-02BBA66B-F3BE-4E21-B933-54A51DEAEE8C.htm#GUID-02BBA66B-F3BE-4E21-B933-54A51DEAEE8C__TABLE_2EB45F8E383F4D3384EB5AFAF2B0F4DE is used to determine which answer to return in the CHECK_IMEI response, determined by which list or lists the IMEI is on. GUID-02BBA66B-F3BE-4E21-B933-54A51DEAEE8C.htm#GUID-02BBA66B-F3BE-4E21-B933-54A51DEAEE8C__TABLE_2EB45F8E383F4D3384EB5AFAF2B0F4DE also shows three possible EIR response types. The EIR response type is a system-wide EIR option that is configured by the user. The combination of the setting of the EIR response type, the list or lists in which the IMEI is located, and the optional IMSI check determines the response returned to the querying MSC.
Table 2-2 Logic for IMEIs in Multiple Lists
Presence in List | EIR Response Type | ||||
---|---|---|---|---|---|
White | Gray | Black | Type 1 | Type 2 | Type 3 |
X | in White List | in White List | in White List | ||
X | X | in Gray List | in Gray List | in Gray List | |
X | X | X | in Black List | in Black List | in Black List |
X | X | in Black List | in Black list | in Black List | |
X | in Gray List | in Gray List | Unknown | ||
X | X | in Black List | in Black List | Unknown | |
X | in Black List | in Black List | Unknown | ||
in White List | Unknown | Unknown |
Example Scenarios
The EIR Response Type is set to Type 3 and an IMSI is not present.
The EIR Response Type is set to Type 2, and an IMSI is not present.