Cisco Cisco ASR 5000
Quality of Service (QoS) Management for SGSN
▀ Quality of Service Management
▄ SGSN Administration Guide, StarOS Release 18
The MS should accept the PDP context modification requested by the network if it is capable of supporting any
modified QoS Negotiated as well as any modified TFT. For a successful modification the MS acknowledges by
returning a Modify PDP Context Accept message. If the MS is incapable of accepting a new QoS Negotiated or
TFT it shall instead de-activate the PDP context with the PDP Context Deactivation Initiated by MS procedure.
returning a Modify PDP Context Accept message. If the MS is incapable of accepting a new QoS Negotiated or
TFT it shall instead de-activate the PDP context with the PDP Context Deactivation Initiated by MS procedure.
On receiving the Modify PDP Context Accept message, or on completion of the RAB modification procedure,
the SGSN returns an Update PDP Context Response (TEID, QoS Negotiated) message to the S-GW.
The S-GW acknowledges the bearer modification to the P- GW by sending an Update Bearer Response (EPS
Bearer Identity) message.
ARP Handling
Difference between Gn SGSN and S4 SGSN
In Create PDP Context response the GGSN sends {1, 2, and 3} as ARP value whereas the S-GW sends “15” value ARP
in Create Session response. In Gn SGSN while sending the RAB assignment request, the Allocation retention priority
values {1, 2, and 3} are mapped to “15” values so there is need of conversion from “3” values to “15” values.
in Create Session response. In Gn SGSN while sending the RAB assignment request, the Allocation retention priority
values {1, 2, and 3} are mapped to “15” values so there is need of conversion from “3” values to “15” values.
In S4 SGSN, since the P-GW sends ARP in the “15” value range there is no need for conversion.
ARP values in Gn SGSN
According to GTPv1 3GPP TS 29.060 clause 7.7.34 Allocation/ Retention priority encodes each priority level defined in
3GPP TS 23.107 as the binary value of the priority level.
3GPP TS 23.107 as the binary value of the priority level.
Quality of Service (QoS) Profile
The Quality of Service (QoS) Profile includes the values of the defined QoS parameters.
Octet “4” carries the Allocation/Retention priority octet that is defined in 3GPP TS 23.107. The Allocation/Retention
priority octet encodes each priority level defined in 3GPP TS 23.107 as the binary value of the priority level.
priority octet encodes each priority level defined in 3GPP TS 23.107 as the binary value of the priority level.
The Allocation/Retention priority field is ignored by the receiver if:
The QoS profile is pre-Release '99.
The QoS profile IE is used to encode the Quality of Service Requested (QoS Req) field of the PDP context IE.
Octet “5” the QoS Profile Data Field is coded according to the 3GPP TS 24.008 [5] Quality of Service IE, octets 3-m.
The minimum length of the field QoS Profile Data is “3” octets, the maximum length is “254” octets.
The minimum length of the field QoS Profile Data is “3” octets, the maximum length is “254” octets.
The clause 11.1.6 “Error handling” defines the handling of the case when the sent QoS Profile information element has
a Length different from the Length expected by the receiving GTP entity.
a Length different from the Length expected by the receiving GTP entity.