Description: This object denotes the PHB which is mapped to the traffic class given by cggsnQosUmtsTrafficClass.

DS architecture is based on number of functional elements, one of which is PHB. PHBs specify queuing, queue management and scheduling characteristics that allow a means of allocating buffer and bandwidth resources at each node among the competing traffic streams.

The various DS PHBs include: signalling - signallingClass(1) The signalling class PHB is only used for the UMTS signalling messages. This DS PHB does not apply to any other IP data packets.

expedited forwarding - efClass(2) The expedited forwarding PHB is used for providing a low loss, low latency, low jitter, assured bandwidth, end-to-end service through the DS domains. Such a service appears to the endpoints like a point-to-point connection, or a virtual leased line.

assured forwarding - afClass(3-6) The assured forwarding PHB provides a means for a provider DS domain to offer different levels of delivery assurances for packets received from a customer DS domain. Four assured forwarding classes: afClass1, afClass2, afClass3 and afClass4 are defined, where each AF class is in each DS node allocated a certain amouont of forwarding resoources(buffer space and bandwidth). IP packets are assigned into one or more of these classes, according to the subscribed service. Within each class the packets are marked by a mobile subscriber, or by the provider DS domain, with one of the three possible drop precedence values. In case of congestion, the drop precedence of a packet determines the relative importance of a packet within the class. Packets in one class are forwarded independently of the packets in another class.

best effort - bestEffort(7) This is the default PHB. The packets of this aggregate are forwarded on an output link whenever the link is not required to satisfy any other PHB.