Node-B Application Protocol (NBAP)

NBAP is the protocol for signaling between UTRAN RNC and NodeB over Iub interface. The Iub interface can be either ATM-based or IP-based.

In ATM-based Iub, NBAP is carried inside SAAL over ATM AAL2.
In IP-based Iub, NBAP is carried inside SCTP over IP.

History

NBAP is specified in 3GPP TS 25.433. IP option for Iub is introduced in UMTS Release 5.

Protocol dependencies

Depending on the Iub interface option either of the following is required:

SSCOP, the SAAL sublayer that transports NBAP signaling messages, for ATM option.
SCTP for IP option

Example traffic

An example of NBAP id-radioLinkDeletion initiating message decoded by Wireshark:

UTRAN Iub interface NBAP signalling
    NBAP-PDU: initiatingMessage (0)
        initiatingMessage
            procedureID
                procedureCode: id-radioLinkDeletion (24)
                ddMode: common (2)
            criticality: reject (0)
            messageDiscriminator: dedicated (1)
            transactionID: shortTransActionId (0)
                shortTransActionId: 0
            initiatingMessageValue
                id-radioLinkDeletion
                    protocolIEs: 3 items
                        Item 0
                            Item
                                id: id-NodeB-CommunicationContextID (143)
                                criticality: reject (0)
                                value
                                    id-NodeB-CommunicationContextID: 23
                        Item 1
                            Item
                                id: id-CRNC-CommunicationContextID (44)
                                criticality: reject (0)
                                value
                                    id-CRNC-CommunicationContextID: 23
                        Item 2
                            Item
                                id: id-RL-informationList-RL-DeletionRqst (213)
                                criticality: notify (2)
                                value
                                    id-RL-informationList-RL-DeletionRqst: 1 item
                                        Item 0
                                            Item
                                                id: id-RL-informationItem-RL-DeletionRqst (206)
                                                criticality: notify (2)
                                                value
                                                    id-RL-informationItem-RL-DeletionRqst
                                                        rL-ID: 0

Wireshark

The NBAP dissector is fully functional however it can presently only be called by a user DLT (data link type) or called by name from another dissector. See FileFormatReference.

Preference Settings

There is no Wireshark preference settings for NBAP.

Example capture file

XXX - Add a simple example capture file to the SampleCaptures page and link from here (see below). Keep this file short, it's also a good idea to gzip it to make it even smaller, as Wireshark can open gzipped files automatically.

SampleCaptures/PROTO.pcap

Display Filter

A complete list of NBAP display filter fields can be found in the display filter reference

Show only the NBAP based traffic:

 nbap

Capture Filter

Because NBAP traces can only currently be read from existing trace files, there is no way to filter for NBAP messages while capturing.

External links

3GPP specification: 25.433

Discussion

Imported from https://wiki.wireshark.org/NBAP on 2020-08-11 23:17:06 UTC