Wireshark-users: [Wireshark-users] IEEE 1588 PTP DataTypes

From: CeSaR PrAdOs <bradomyn@xxxxxxxxx>
Date: Thu, 2 Jul 2009 12:10:59 +0200
Hi,

I'm developing a PTP software (IEEE 1588)and  I was so surprised when I saw the definitions of the data type used in WhireShark's filter for the PTP standard v2. At the beginning I was freaking out because no one of my PTP packets machted with the information in Wireshark.

This is the definition of PTP fileds in whireshark:
http://www.wireshark.org/docs/dfref/p/ptp.html

and for example the the data type for the PTP msg header, according to the spec is:

    uint4_t             messageType;
    uint4_t            transportSpecific;
    uint4_t         versionPTP;          
    uint4_t            reserved1;
    uint16_t         messageLength;
    uint8_t            domainNumber;      
    uint8_t            reserved2;
    octet            flagField[2];
    int64_t            correctionField;
    uint8_t            reserved3;
    portIdentity     sourcePortId;
    uint16_t        sequenceId;
    uint8_t            controlfield;
    int8_t            logMessageInterval;


So we have for instance in the spec

  messageType --> 4 bits

WhireShark

  messageType -->  Unsigned 8-bit integer

does anybody tell why??

I mean it's a stadard we should follow the spec literally...

Thank you,

Cesar