DCAP Nokia files

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1

Hi,

I would like to build a DCAP parser.

The files are binary.

Do you have any idea where how I can find documentation about the file structure and fields?

Thank you in advance

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Hi, Write me your email and I will send you my notes about Nokia CDR format

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Rubao is making a parser and asked about the format. I know a little about it, as I’ve been working with various CDR formats coming from various vendor equipment for almost 10 years. Maybe someone else will be interested in this. Enough self-promotion. Unfortunately, all these documents are confidential, and even if I accidentally got them, I wouldn’t be able to show them. But I have my notes.

So, about Nokia. Nokia has created a format that’s quite convenient for parsing, I’m talking about parsing binary files. What does the format represent?

A call record begins with 3 bytes of information that’s meaningful for parsing: 2 bytes of RECORD_LENGTH and 1 byte of RECORD_TYPE. Everything else is done from these bytes.
The 2 bytes of RECORD_LENGTH, as the name suggests, are the record length. These two bytes are also included in the record length. This field is available in all CDRs and is a hex word.
The 1 byte of RECORD_TYPE indicates the type of CDR in question.

So, with the length and type answers, we can begin to analyze it further. The Nokia format document lists the fields and their lengths.

The main problem with parsing, in my opinion, is that without knowing the message format, it’s quite difficult to parse the record. Unlike, for example, Huawei records, where a byte (or more) is the field name, a byte is the size, and x bytes is the field content. Here, seeing the messages, we can only cut them into larger chunks by type, knowing what I wrote.
It’s also possible there are differences depending on the software version. I know that individual fields are added to the end; for example, fields for EUTRAN transmission for 4G are added.

For example, a CDR record could start like this: 29 00 00… where the first two bytes indicate the block size and the third indicates the record type.

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