Cisco ASR 5000 Series, Обзор продукта

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Serving GPRS Support Node (SGSN) Overview
▀ Features and Functionality - Basic
▄ Cisco ASR 5000 Series Product Overview
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Identity Request
This procedure is used to retrieve IMSI and IMEI-SV from the MN. The SGSN executes this procedure only when the
MN does not provide the IMSI and the MM context for the subscriber is not present in the SGSN‘s data-VLR.
Location Management
The SGSN‘s 3GPP compliance for location management ensures efficient call handling for mobile users.
The SGSN supports routing area updates (RAU) for location management. The SGSN implements standards based
support for:
Periodic RAUs
Intra-SGSN RAUs
Inter-SGSN RAUs.
The design of the SGSN allows for very high scalability of RAUs. In addition, the high capacity of the SGSN and Flex
functionality provides a great opportunity to convert high impact Inter-SGSN RAUs to lower impact Intra-SGSN RAUs.
The SGSN provides functionality to enforce the following RAU restrictions:
Prohibition of GPRS services
Enforce identity request
Enforce IMEI check
PLMN restriction
Roaming restrictions
The SGSN also provides functionality to optionally supply the following information to the MN:
P-TMSI Signature and Allocated P-TMSI
List of received N-PDU numbers for loss less relocation
Negotiated READY timer value
Equivalent PLMNs
PDP context status
Network features supported
Multiple PLMN Support
With this feature, the 2.5G and 3G SGSNs now support more than one PLMN ID per SGSN. Multiple PLMN support
facilitates MS handover from one PLMN to another PLMN.
Multiple PLMN supportalso means an operator can 'hire out' their infrastructure to other operators who may wish to use
their own PLMN IDs. As well, multiple PLMN support enables an operator to assign more than one PLMN ID to a cell-