для Cisco Cisco Packet Data Gateway (PDG)
SGSN Changes in Release 16
SGSN Enhancements for 16.2 ▀
Release Change Reference, StarOS Release 16 ▄
477
CSCuo86321- Issue with show subscriber and clear subscriber
Feature Changes
Evaluation of Idle time
Previous Behavior: The evaluation of idle time in show subscriber and clear subscriber CLI commands is based on
MM signalling.
MM signalling.
New Behavior: The evaluation of idle time in show subscriber and clear subscriber CLI commands is now based on
data session idle time of the subscriber.
data session idle time of the subscriber.
Customer Impact: The show subscriber and clear subscriber CLI commands with idle time will now work on data
session idle time.
session idle time.
CSCuo87321- Notify PGW of modified QoS after negotiation with RNC
Feature Changes
Notify PGW of Modified QoS After Negotiation With RNC
Previous Behavior: During PDP context activation if the RNC downgrades the QoS in RAB Assignment Response,
the S4-SGSN rejects the PDP with cause "Insufficient Resources". The 3GPP standards does not permit QoS re-
negotiation by RAN in EPC. The S4-SGSN is considered as an EPC Node and when it cannot allocate the PCRF-
assigned QoS due to RAN or UE capabilities, it rejects the PDP Creation Request. The S4-SGSN supports local QoS
capping (up to UE/RNC capabilities) to at-least allow PDP creation in this scenario, however this behavior is not
permissible as it may lead to potential overcharging due to difference in maximum-bit-rates as enforced by PGW and as
allowed by RAN.
the S4-SGSN rejects the PDP with cause "Insufficient Resources". The 3GPP standards does not permit QoS re-
negotiation by RAN in EPC. The S4-SGSN is considered as an EPC Node and when it cannot allocate the PCRF-
assigned QoS due to RAN or UE capabilities, it rejects the PDP Creation Request. The S4-SGSN supports local QoS
capping (up to UE/RNC capabilities) to at-least allow PDP creation in this scenario, however this behavior is not
permissible as it may lead to potential overcharging due to difference in maximum-bit-rates as enforced by PGW and as
allowed by RAN.
New Behavior: The issue is resolved by informing capped QoS to PGW/PCRF using the Modify Bearer Command to
modify the APN-AMBR at the PGW. A new CLI option
modify the APN-AMBR at the PGW. A new CLI option
inform-pgw
is provided for the command
qos-
modification
under the SGSN Service configuration command to enable or disable sending of Modify Bearer
Command to the PGW. By default this option is disabled. When this option is enabled, the S4-SGSN triggers a Modify
Bearer Command if QoS is downgraded by the RNC in RAB Assignment Procedure. To avoid looping of messages
between S4-SGSN and PGW, The PCRF should be configured to "NOT" upgrade QoS when RAT-Type is 3G.
Bearer Command if QoS is downgraded by the RNC in RAB Assignment Procedure. To avoid looping of messages
between S4-SGSN and PGW, The PCRF should be configured to "NOT" upgrade QoS when RAT-Type is 3G.
Command Changes
qos-modification
The
qos-modification
command under the SGSN Service Configuration mode provides the operator with the
flexibility to control RAB setup and negotiations based on the RNC. If the keyword
allow-s4-rab-negotiation
is
specified as a part of the configuration and if the S4 interface is used for PDP activation then the SGSN locally accepts
what the RNC sends as QoS in the RAB Assignment Response and sends that QoS in the Activate Response. A new
keyword
what the RNC sends as QoS in the RAB Assignment Response and sends that QoS in the Activate Response. A new
keyword
inform-pgw
is included as a part of the
allow-s4-rab-negotiation
CLI option. This CLI option is used
to enable or disable sending of Modify Bearer Command to the PGW. By default this option is disabled. When this
option is enabled, the S4-SGSN triggers a Modify Bearer Command if QoS is downgraded by the RNC in RAB
Assignment Procedure. The PCRF should be configured to “NOT” upgrade QoS when RAT-Type is 3G.
option is enabled, the S4-SGSN triggers a Modify Bearer Command if QoS is downgraded by the RNC in RAB
Assignment Procedure. The PCRF should be configured to “NOT” upgrade QoS when RAT-Type is 3G.
configure