Cisco Cisco Packet Data Gateway (PDG) Documentation Roadmaps
Serving GPRS Support Node (SGSN) Overview
▀ Features and Functionality - Enhanced and Licensed
▄ Cisco ASR 5000 Series Product Overview
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MS requested QoS - The QoS requested by the UE on pdp-context activation.
DSCP Marking
The SGSN can perform DSCP marking of the GTP-U packets according to allowed-QoS to PHB mapping. The default
mapping matches that of the UMTS to IP QoS mapping defined in 3GPP TS 29.208.
mapping matches that of the UMTS to IP QoS mapping defined in 3GPP TS 29.208.
Traffic Policing
The SGSN can police uplink and downlink traffic according to predefined QoS negotiated limits fixed on the basis of
individual contexts - either primary or secondary. The SGSN employs the Two Rate Three Color Marker (RFC2698)
algorithm for traffic policing. The algorithm meters an IP packet stream and marks its packets either green, yellow, or
red depending upon the following variables:
individual contexts - either primary or secondary. The SGSN employs the Two Rate Three Color Marker (RFC2698)
algorithm for traffic policing. The algorithm meters an IP packet stream and marks its packets either green, yellow, or
red depending upon the following variables:
PIR - Peak Information Rate (measured in bytes/second)
CIR - Committed Information Rate (measured in bytes/second)
PBS - Peak Burst Size (measured in bytes)
CBS - Committed Burst Size (measured in bytes)
The following figure depicts the working of the trTCM algorithm: