问题
I need to extract the voice data out of the CC (Content of Communication). It is stored into binfiles and it's delivered by the HI3. For doing this, I need the information of the codec written of the SDP part of the SIP protocol, which I can see in the datafiles. So until here everything is fine.
But there is one problem: I cannot see the correlation number which correlates the payload of CC with the control information of IRI.
In circuit switched GSM/UMTS it is a part of the LIID (Lawfull Intercept Identification number), called CIN, ETSI ES 201 671 V3.1.1 (2007-05) page 23 chapter 6.6.2 [ https://www.etsi.org/deliver/etsi_es/201600_201699/201671/03.01.01_60/es_201671v030101p.pdf ].
But what's the name of this parameter in VoLTE (Voice over LTE)? I didn't find it in any documentation and or how can I extract it from SIP?
In another document I've found a table IRI REPORT FOR SIP MESSAGE. There is the following headline: ASN.1 parameters, MOC, Comments.
The parameters are: hi2epsDomainId, lawfulInterceptionIdentifier,.. ..ePSCorrelationNumber,.. .., sipMessage, correlation.
The parameters I'm looking for is 'correlation', which is described in the comments like this:
"iri-CC.cc = correlationNumber, where correlationNumber is the value used to identify all notification within the same session and to relate them to the possible content of communication."
That's really great, but how can I find this value?
Thanks
来源：https://stackoverflow.com/questions/60598809/name-of-parameter-correlation-number-between-cc-and-iri-in-iri-datafile-voice-o