A TFT is created for a new PDP context using the same PDP address and the same APN as an existing PDP context but with a different QoS profile. This new PDP context is called a secondary PDP context and is activated during a secondary PDP context activation procedure. After a TFT has been created for a new secondary PDP context, it is sent by the MS to the network during the secondary PDP context activation procedure. A TFT may be modified during a PDP context modification procedure initiated by the MS. A TFT is deleted when the associated PDP context is deactivated.
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During packet transmission between the MS and the external packet network, the GGSN will compare the parameters of the IP PDU header with packet filters of the TFT. If a match is found between the IP PDU header and a packet filter, the GGSN is able to direct the IP PDU from the interconnected external PDN to the suitable activated PDP context identified by the NSAPI parameter.