Wireshark · Wireshark-dev: [Wireshark-dev] NBAP -> RRC Help

[Rick Bywater <rbywater@xxxxxxxxxx>]

All,

I am looking at the NBAP dissector to correct/complete its decode of IB_SG_DATA.  According to the specifications, the IB_SG_DATA has RRC encoding.  So, for each IE IB_SG_DATA IE, the RRC dissector for that segment (presumably) should be called.  Currently, those IEs simply decode as bit string?  Here is an abbreviated section of the decode I am talking about:

Frame 1 (330 bytes on wire, 330 bytes captured)
Ethernet II, Src: Dell_ed:a0:a4 (00:11:43:ed:a0:a4), Dst: DellComp_f2:3c:f1 (00:b0:d0:f2:3c:f1)
Internet Protocol, Src: 172.16.5.201 (172.16.5.201), Dst: 10.30.86.200 (10.30.86.200)
Stream Control Transmission Protocol, Src Port: 49153 (49153), Dst Port: 49152 (49152)
UTRAN Iub interface NBAP signalling
    NBAP-PDU: initiatingMessage (0)
        initiatingMessage
            procedureID
                procedureCode: id-systemInformationUpdate (32)
                ddMode: common (2)
            criticality: reject (0)
            messageDiscriminator: common (0)
            transactionID: longTransActionId (1)
                longTransActionId: 80
            value
                SystemInformationUpdateRequest
                    protocolIEs: 2 items
                        Item 0: id-C-ID
                            ProtocolIE-Field
                                id: id-C-ID (25)
                                criticality: reject (0)
                                value
                                    C-ID: 0
                        Item 1: id-MIB-SB-SIB-InformationList-SystemInfoUpdateRqst
                            ProtocolIE-Field
                                id: id-MIB-SB-SIB-InformationList-SystemInfoUpdateRqst (134)
                                criticality: reject (0)
                                value
                                    MIB-SB-SIB-InformationList-SystemInfoUpdateRqst: 7 items
                                        Item 0
                                            MIB-SB-SIB-InformationItem-SystemInfoUpdateRqst
                                                iB-Type: mIB (0)
                                                iB-OC-ID: 1
                                                deletionIndicator: no-Deletion (0)
                                                    no-Deletion: id-SegmentInformationListIE-SystemInfoUpdate
                                                        iB-SG-REP: rep8 (1)
                                                        segmentInformationList
                                                            id: id-SegmentInformationListIE-SystemInfoUpdate (266)
                                                            criticality: reject (0)
                                                            value
                                                                SegmentInformationListIE-SystemInfoUpdate: 1 item
                                                                    Item 0
                                                                        SegmentInformationItem-SystemInfoUpdate
                                                                            iB-SG-POS: 0
                                                                            segment-Type: complete-SIB (5)
                                                                            iB-SG-DATA: 609104650004062120321101990C8D4400D01CA880E8 [bit length 176]


So, my question is how is that done?  Can a higher level dissector be invoked via an ASN.1 dissector while returning back later to finish decoding the remaining IEs?  If so, where is an example I can follow?

Thanks,
Rick