Cisco Cisco ASR 5000
Serving GPRS Support Node (SGSN) Overview
▀ Features and Functionality
▄ SGSN Administration Guide, StarOS Release 18
AAA Changes To Support Location Services (LCS) Feature
The Location Services (LCS) feature in SGSN provides the mechanism to support mobile location services for
operators, subscribers and third party service providers. AAA changes have been made to support the LCS feature. A
new CDR type Mobile Originated Location Request CDRs (LCS-MO-CDR) is introduced. LCS-MO-CDRs support the
standard dictionaries.
operators, subscribers and third party service providers. AAA changes have been made to support the LCS feature. A
new CDR type Mobile Originated Location Request CDRs (LCS-MO-CDR) is introduced. LCS-MO-CDRs support the
standard dictionaries.
For detailed information on LCS-MO-CDRs, refer to the GTPP Interface Administration and Reference.
APN Aliasing
In many situations, the APN provided in the Activation Request is unacceptable – perhaps it does not match with any of
the subscribed APNs or it is misspelled – and would result in the SGSN rejecting the Activation Request. The APN
Aliasing feature enables the operator to override an incoming APN – specified by a subscriber or provided during the
APN selection procedure (TS 23.060) – or replace a missing APN with an operator-preferred APN.
the subscribed APNs or it is misspelled – and would result in the SGSN rejecting the Activation Request. The APN
Aliasing feature enables the operator to override an incoming APN – specified by a subscriber or provided during the
APN selection procedure (TS 23.060) – or replace a missing APN with an operator-preferred APN.
The APN Aliasing feature provides a set of override functions: Default APN, Blank APN, APN Remapping, and
Wildcard APN to facilitate such actions as:
Wildcard APN to facilitate such actions as:
overriding a mismatched APN with a default APN.
overriding a missing APN (blank APN) with a default or preferred APN.
overriding an APN on the basis of charging characteristics.
overriding an APN by replacing part or all of the network or operator identifier with information defined by the
operator, for example, MNC123.MCC456.GPRS could be replaced by MNC222.MCC333.GPRS.
overriding an APN for specific subscribers (based on IMSI) or for specific devices (based on IMEI).
Default APN
Operators can configure a “default APN” for subscribers not provisioned in the HLR. The default APN feature will be
used in error situations when the SGSN cannot select a valid APN via the normal APN selection process. Within an
APN remap table, a default APN can be configured for the SGSN to:
used in error situations when the SGSN cannot select a valid APN via the normal APN selection process. Within an
APN remap table, a default APN can be configured for the SGSN to:
override a requested APN when the HLR does not have the requested APN in the subscription profile.
provide a viable APN if APN selection fails because there was no “requested APN” and wildcard subscription
was not an option.
In either of these instances, the SGSN can provide the default APN as an alternate behavior to ensure that PDP context
activation is successful.
activation is successful.
Recently, the SGSN’s default APN functionality was enhanced so that if a required subscription APN is not present in
the subscriber profile, then the SGSN will now continue the activation with another configured 'dummy' APN. The call
will be redirected, via the GGSN, to a webpage informing the user of the error and prompting to subscribe for services.
the subscriber profile, then the SGSN will now continue the activation with another configured 'dummy' APN. The call
will be redirected, via the GGSN, to a webpage informing the user of the error and prompting to subscribe for services.
APN Redirection per APN with Lowest Context-ID
The APN Redirection per APN with Lowest Context-ID feature adds the flexibility to select the subscription APN with
the least context ID when the APN is not found in the subscription. SGSN already provides sophisticated APN
replacement with support for first-in-subscription, default APN, blank APN, and wildcard APN. This latest feature
the least context ID when the APN is not found in the subscription. SGSN already provides sophisticated APN
replacement with support for first-in-subscription, default APN, blank APN, and wildcard APN. This latest feature