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英语翻译
专有名词可以保留
The P-CSCF shall send service information to the PCRF upon every SIP message that includes an SDP answer payload.The service information shall be derived both from the SDP offer and the SDP answer.This ensures that the PCRF receives proper information to perform media authorization for all possible IMS session set-up scenarios,and that the PCRF is also capable of handling session modifications.
All media components in the SDP shall be authorized.Therefore,the P-CSCF shall derive a media component within the session information from every SDP media component.The SDP contains sufficient information about the session,such as the end-points' IP address and port numbers and bandwidth requirements.
The P-CSCF shall derive Flow-Description AVP within the service information from the SDP as follows:
- An uplink Flow-Description AVP shall be formed as follows:The destination address and port number shall be taken from the connection information parameter of the SDP sent by the P-CSCF in downlink direction,while the source IP address may be formed from the address present in the SDP received by the P-CSCF in uplink direction (taking into account only the 64 bit prefix of the IPv6 address),and the source port number shall be wildcarded.For example,assuming UE A sends an SDP to UE B,the PCRF of UE B uses the address present in this SDP for the destination address of UE B's uplink Flow-Description AVP,while the PCRF of the UE A uses the 64 bit prefix of the same address for the source address of UE A's uplink Flow-Description AVP.If the source address is not formed from the 64 bit prefix,the source address shall be wildcarded.
- An downlink Flow-Description AVP shall be formed as follows:The destination address and port number shall be taken from the connection information parameter of the SDP received by the P-CSCF in uplink direction,while the source IP address may be formed (in order to reduce the possibilities of bearer misuse) from the destination address in the SDP sent by the P-CSCF in downlink direction (taking into account only the 64 bit prefix of the IPv6 address) and the source port number shall be wildcarded.For example,assuming UE A sends an SDP to UE B,the PCRF of UE a uses the address present in this SDP for the destination address of UE A's downlink Flow-Description AVP,while the PCRF of UE B uses the 64 bit prefix of the same address for the source address of UE B's downlink Flow-Description AVP.If the source address is not formed from the 64 bit prefix,the source address shall be wildcarded.
The P-CSCF shall derive the bandwidth information within the service information,from the "b=AS" SDP parameter.For the possibly associated RTCP IP flows,the P-CSCF shall use the SDP "b=RR" and "b=RS" parameters,if present.The "b=AS","b=RR" and "b=RS" parameters in the SDP contain all the overhead coming from the IP-layer and the layers above,e.g.IP,UDP,RTP and RTCP payload,or IP,UDP and RTCP.
专有名词可以保留
The P-CSCF shall send service information to the PCRF upon every SIP message that includes an SDP answer payload.The service information shall be derived both from the SDP offer and the SDP answer.This ensures that the PCRF receives proper information to perform media authorization for all possible IMS session set-up scenarios,and that the PCRF is also capable of handling session modifications.
All media components in the SDP shall be authorized.Therefore,the P-CSCF shall derive a media component within the session information from every SDP media component.The SDP contains sufficient information about the session,such as the end-points' IP address and port numbers and bandwidth requirements.
The P-CSCF shall derive Flow-Description AVP within the service information from the SDP as follows:
- An uplink Flow-Description AVP shall be formed as follows:The destination address and port number shall be taken from the connection information parameter of the SDP sent by the P-CSCF in downlink direction,while the source IP address may be formed from the address present in the SDP received by the P-CSCF in uplink direction (taking into account only the 64 bit prefix of the IPv6 address),and the source port number shall be wildcarded.For example,assuming UE A sends an SDP to UE B,the PCRF of UE B uses the address present in this SDP for the destination address of UE B's uplink Flow-Description AVP,while the PCRF of the UE A uses the 64 bit prefix of the same address for the source address of UE A's uplink Flow-Description AVP.If the source address is not formed from the 64 bit prefix,the source address shall be wildcarded.
- An downlink Flow-Description AVP shall be formed as follows:The destination address and port number shall be taken from the connection information parameter of the SDP received by the P-CSCF in uplink direction,while the source IP address may be formed (in order to reduce the possibilities of bearer misuse) from the destination address in the SDP sent by the P-CSCF in downlink direction (taking into account only the 64 bit prefix of the IPv6 address) and the source port number shall be wildcarded.For example,assuming UE A sends an SDP to UE B,the PCRF of UE a uses the address present in this SDP for the destination address of UE A's downlink Flow-Description AVP,while the PCRF of UE B uses the 64 bit prefix of the same address for the source address of UE B's downlink Flow-Description AVP.If the source address is not formed from the 64 bit prefix,the source address shall be wildcarded.
The P-CSCF shall derive the bandwidth information within the service information,from the "b=AS" SDP parameter.For the possibly associated RTCP IP flows,the P-CSCF shall use the SDP "b=RR" and "b=RS" parameters,if present.The "b=AS","b=RR" and "b=RS" parameters in the SDP contain all the overhead coming from the IP-layer and the layers above,e.g.IP,UDP,RTP and RTCP payload,or IP,UDP and RTCP.
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