Cisco Cisco ASR 5000
Quality of Service (QoS) Management for SGSN
▀ Quality of Service Management
▄ SGSN Administration Guide, StarOS Release 18
Quality of Service Management
The network associates a certain Quality of Service (QoS) with each data transmission in the GPRS packet mode. The
QoS attributes are collectively termed as a “QoS Profile”. The PDP context stores the QoS Profile information. The QoS
management is performed by using the PDP context management procedures, such as PDP context activation,
modification and de-activation. QoS enables the differentiation between services provided.
QoS attributes are collectively termed as a “QoS Profile”. The PDP context stores the QoS Profile information. The QoS
management is performed by using the PDP context management procedures, such as PDP context activation,
modification and de-activation. QoS enables the differentiation between services provided.
SGSN Quality of Service Management
The SGSN applies an admission control function on each PDP context activation request. The function results in further
processing of the request; that is, either negotiation of the QoS with the Mobile Subscriber (MS), or rejection of the PDP
context activation request. The SGSN negotiates QoS with the MS when the level requested by the subscriber cannot be
supported or when the QoS level negotiated from the previous SGSN cannot be supported at an inter-SGSN routing area
update. The response to the mobile subscriber depends on the provisioned subscription data, the requested QoS, the QoS
permitted by the Gateway node and the QoS permitted by the Radio Access Network.
processing of the request; that is, either negotiation of the QoS with the Mobile Subscriber (MS), or rejection of the PDP
context activation request. The SGSN negotiates QoS with the MS when the level requested by the subscriber cannot be
supported or when the QoS level negotiated from the previous SGSN cannot be supported at an inter-SGSN routing area
update. The response to the mobile subscriber depends on the provisioned subscription data, the requested QoS, the QoS
permitted by the Gateway node and the QoS permitted by the Radio Access Network.
Quality of Service Attributes
In an End-to- End Service the network user is provided with a certain Quality of Service, which is specified by a set of
QoS attributes or QoS profile. The first list of attributes was defined in Release 97/98 of the 3GPP recommendations but
these are now replaced by Release 99 3GPP recommendations. Many QoS profiles can be defined by the combination of
these attributes. Each attribute is negotiated by the MS and the GPRS/UMTS/LTE network. If the negotiated QoS
profiles are accepted by both parties then the network will have to provide adequate resources to support these QoS
profiles.
QoS attributes or QoS profile. The first list of attributes was defined in Release 97/98 of the 3GPP recommendations but
these are now replaced by Release 99 3GPP recommendations. Many QoS profiles can be defined by the combination of
these attributes. Each attribute is negotiated by the MS and the GPRS/UMTS/LTE network. If the negotiated QoS
profiles are accepted by both parties then the network will have to provide adequate resources to support these QoS
profiles.
In Release 97/98 recommendations, the PDP context is stored in the MS, SGSN and GGSN. It represents the relation
between one PDP address, PDP type (static or dynamic address), the address of a GGSN that serves as an access point
to an external PDN, and one Quality of Service (QoS) profile. PDP contexts with different QoS parameters cannot share
the same PDP address. In Release 99 recommendations a subscriber can use more than one PDP contexts with different
QoS parameters and share the same PDP address.
between one PDP address, PDP type (static or dynamic address), the address of a GGSN that serves as an access point
to an external PDN, and one Quality of Service (QoS) profile. PDP contexts with different QoS parameters cannot share
the same PDP address. In Release 99 recommendations a subscriber can use more than one PDP contexts with different
QoS parameters and share the same PDP address.
Quality of Service Attributes in Release 97/98
In Release 97/98 of the 3GPP recommendations, QoS is defined according to the following attributes:
Precedence Class: This attribute indicates the packet transfer priority under abnormal conditions, for example
during a network congestion load.
Reliability Class: This attribute indicates the transmission characteristics. It defines the probability of data loss,
data delivered out of sequence, duplicate data delivery, and corrupted data. This parameter enables the
configuration of layer “2” protocols in acknowledged or unacknowledged modes.
configuration of layer “2” protocols in acknowledged or unacknowledged modes.
Peak Throughput Class: This attribute indicates the expected maximum data transfer rate across the network
for a specific access to an external packet switching network (from 8 Kbps up to 2,048 Kbps).
Mean Throughput Class: This attribute indicates the average data transfer rate across the network during the
remaining lifetime of a specific access to an external packet switching network (best effort, from 0.22 bps up to
111 Kbps).
111 Kbps).