Cisco Cisco ASR 5000
Quality of Service (QoS) Management for SGSN
Quality of Service Management ▀
SGSN Administration Guide, StarOS Release 18 ▄
Delay Class: This attribute defines the end-to-end transfer delay for the transmission of Service Data Units
(SDUs) through the GPRS network. The SDU represents the data unit accepted by the upper layer of GPRS
and conveyed through the GPRS network.
and conveyed through the GPRS network.
Quality of Service Attributes in Release 99
The attributes of GPRS QoS were modified in Release 99 of the 3GPP recommendations in order to be identical to the
ones defined for UMTS.
ones defined for UMTS.
The quality of service is a type “4” information element with a minimum length of “14” octets and a maximum length of
“18” octets.
“18” octets.
The Release 99 of 3GPP recommendations defines QoS attributes such as Traffic class, Delivery order, SDU format
information, SDU error ratio, Maximum SDU size, Maximum bit rate for uplink, Maximum bit rate for downlink,
Residual bit error ratio, Transfer delay, Traffic-handling priority, Allocation/retention priority, and Guaranteed bit rate
for uplink and Guaranteed bit rate for downlink. The attributes are listed below:
information, SDU error ratio, Maximum SDU size, Maximum bit rate for uplink, Maximum bit rate for downlink,
Residual bit error ratio, Transfer delay, Traffic-handling priority, Allocation/retention priority, and Guaranteed bit rate
for uplink and Guaranteed bit rate for downlink. The attributes are listed below:
Traffic Class: Indicates the application type (conversational, streaming, interactive, background). Four classes
of traffic have been defined for QoS:
Conversational Class: These services are dedicated to bi-directional communication in real time (for
example, voice over IP and video conferencing).
Streaming Class: These services are dedicated to uni-directional data transfer in real time (for
example, audio streaming and one-way video).
Interactive Class: These services are dedicated to the transport of human or machine interaction with
remote equipment (for example, Web browsing, access to a server and access to a database).
Background Class: These services are dedicated to machine-to-machine communication; this class of
traffic is not delay sensitive (for example, e-mail and SMS).
Delivery Order: Indicates the presence of an in-sequence SDU delivery (if any).
Delivery of Erroneous SDUs: Indicates if erroneous SDUs are delivered or discarded.
SDU Format Information: Indicates the possible exact sizes of SDUs.
SDU Error Ratio: Indicates the maximum allowed fraction of SDUs lost or detected as erroneous.
Maximum SDU Size: Indicates the maximum allowed SDU size (from “10” octets up to “1,520” octets).
Maximum Bit Rate for Uplink: Indicates the maximum number of bits delivered to the network within a period
of time (from “0” up to “8,640” Kbps).
Maximum Bit Rate for Downlink: Indicates the maximum number of bits delivered by the network within a
period of time (from “0” up to “8,640” Kbps).
Residual Bit Error Ratio:Indicates the undetected bit error ratio for each sub-flow in the delivered SDUs.
Transfer Delay: Indicates the maximum time of SDU transfer for 95th percentile of the distribution of delay for
all delivered SDUs.
Traffic-Handling Priority: Indicates the relative importance of all SDUs belonging to a specific GPRS bearer
compared with all SDUs of other GPRS bearers.
Allocation/Retention Priority:Indicates the relative importance of resource allocation and resource retention for
the data flow related to a specific GPRS bearer compared with the data flows of other GPRS bearers (this
attribute is useful when resources are scarce).
attribute is useful when resources are scarce).