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ASN Gateway QoS and Service Flow Configuration
▀ Introduction
▄ Cisco ASR 5000 Series Access Service Network Gateway Administration Guide
OL-22953-01
Introduction
This section provides an introduction to Quality of Service (QoS) and service flow ID management for a subscriber.
Connection-oriented MAC Architecture
Support for QoS is a fundamental part of the WiMAX service. QoS is controlled with a connection-oriented MAC
architecture. All downlink and uplink connections are controlled by the serving base station. Before any data
transmission occurs, the base station and the mobile station establish a unidirectional logical link, a connection, between
the two MAC-layer peers. Each connection is identified by a connection identifier (CID), which serves as a temporary
address for data transmissions over the link. In addition to connections for transferring user data, the WiMAX MAC
defines three management connections—the basic, primary, and secondary connections. These three management
connections are used for such functions as ranging.
architecture. All downlink and uplink connections are controlled by the serving base station. Before any data
transmission occurs, the base station and the mobile station establish a unidirectional logical link, a connection, between
the two MAC-layer peers. Each connection is identified by a connection identifier (CID), which serves as a temporary
address for data transmissions over the link. In addition to connections for transferring user data, the WiMAX MAC
defines three management connections—the basic, primary, and secondary connections. These three management
connections are used for such functions as ranging.
WiMAX Service Flow and QoS
WiMAX provides the concept of service flow. A service flow is a unidirectional flow of packets with a set of QoS
parameters, identified by a service flow identifier (SFID). The QoS parameters include traffic priority, maximum
sustained traffic rate, maximum burst rate, minimum tolerable rate, scheduling type, maximum delay, tolerated jitter,
service data unit type and size, bandwidth request mechanism to be used, transmission PDU formation rules, and so on.
parameters, identified by a service flow identifier (SFID). The QoS parameters include traffic priority, maximum
sustained traffic rate, maximum burst rate, minimum tolerable rate, scheduling type, maximum delay, tolerated jitter,
service data unit type and size, bandwidth request mechanism to be used, transmission PDU formation rules, and so on.
You can provision service flows through a network management system or create them dynamically through defined
signaling mechanisms. The base station is responsible for issuing the SFID and mapping it to unique CIDs. You can also
map service flows to DiffServ code points or MPLS flow labels to enable end-to-end IP-based QoS.
signaling mechanisms. The base station is responsible for issuing the SFID and mapping it to unique CIDs. You can also
map service flows to DiffServ code points or MPLS flow labels to enable end-to-end IP-based QoS.
Within a WiMAX ASN, QoS enforcement is administered by the Service Flow Authorization (SFA) component in the
ASN Gateway (also referred to as Anchor Policy Charging Enforcement Function, A-PCEF). The SFA component
provides traffic management and QoS policy management for subscriber service flows.
ASN Gateway (also referred to as Anchor Policy Charging Enforcement Function, A-PCEF). The SFA component
provides traffic management and QoS policy management for subscriber service flows.
With multiflow QoS, static traffic policies are established for various subscriber application-level service flows. It can
be used in Simple IP or Mobile IP usage scenarios. The policies are stored in a Subscriber Policy Repository (SPR)
database and retrieved as authenticated QoS profiles by the ASN Gateway. The A-PCEF negotiates via R6 with the
Service Flow Manager (SFM) function on the base station. If the authorized QoS profile matches the available base
station resources, the request is granted. The A-PCEF provides traffic classification, admission control, prioritization
(DSCP marking), per-session/per-flow bandwidth control, and flow mapping across application-specific R6/R4 GRE
tunnels.
be used in Simple IP or Mobile IP usage scenarios. The policies are stored in a Subscriber Policy Repository (SPR)
database and retrieved as authenticated QoS profiles by the ASN Gateway. The A-PCEF negotiates via R6 with the
Service Flow Manager (SFM) function on the base station. If the authorized QoS profile matches the available base
station resources, the request is granted. The A-PCEF provides traffic classification, admission control, prioritization
(DSCP marking), per-session/per-flow bandwidth control, and flow mapping across application-specific R6/R4 GRE
tunnels.
In conjunction with multiflow QoS, the ASN Gateway provides configurable accounting on a per-session, per-R6, or
per-service flow basis. Multiflow QoS enables the separation of OFDM radio access connection into multiple logical
Connection IDs (CIDs), with each pair of forward and reverse sub-channels transporting one or more application flows.
per-service flow basis. Multiflow QoS enables the separation of OFDM radio access connection into multiple logical
Connection IDs (CIDs), with each pair of forward and reverse sub-channels transporting one or more application flows.
The ASN Gateway supports static pre-provisioned service flows. A total of up to six bi-directional service flows per
subscriber R6 or R4 session are possible.
subscriber R6 or R4 session are possible.
Multi-Flow QoS provides an enhanced user experience via end-to-end differentiated QoS connection-oriented services
for isochronous voice and delay-sensitive multimedia applications over broadband wireless WiMAX networks. This
feature also enables service convergence and provides the foundation for IMS service control.
for isochronous voice and delay-sensitive multimedia applications over broadband wireless WiMAX networks. This
feature also enables service convergence and provides the foundation for IMS service control.
The QoS implementation provides following supports: