evolved Common Public Radio Interface (eCPRI)

evolved Common Public Radio Interface (eCPRI) is a protocol, which will be used in fronthaul transport network. It will be included in standard Ethernet frames and UDP frames. There are 8 Message Types to decode with eCPRI Specification V1.2.

Packet format

eCPRI Common Header

eCPRI Payload

eCPRI Protocol Revision

Reserved

eCPRI Message Type

eCPRI Payload Size

4 Bit

3 Bit

1 Bit

8 Bit = 1 Byte

16 Bit = 2 Bytes

0 - 65535 Bytes

eCPRI Header fields

eCPRI Protocol Revision field

Available revison values:

| 0x1 | shall follow specification V1.0 | | 0x2-0xF | reserved for future; temporarily vendor specific |

Reserved field

Reserved field should be filled with 000b.

C field

The C field indicates a concatenation.

If C = 0, then is this the last eCPRI Message inside the eCPRI PDU.
If C = 1, then another eCPRI Message follows within the same PDU. Between this two messages are padding bits (0-3). The new message starts at a 4-Byte boundary.

eCPRI Message Type field

There are 255 Message Types. 0 - 7 is specified in the Specification, 8 - 63 is reserved and 64 - 255 vendor specific.

Message Type	Name
0x00	IQ Data
0x01	Bit Sequence
0x02	Real-Time Control Data
0x03	Generic Data Transfer
0x04	Remote Memory Access
0x05	One-way Delay Measurement
0x06	Remote Reset
0x07	Event Indication
0x08 - 0x3F	Reserved
0x40 - 0xFF	Vendor Specific

eCPRI Payload Size field

It's the size of following payload. The eCPRI Payload doesn't include any padding bytes. The maximum payload size is 65535, but is limited by the transport network, e.g. Ethernet.

eCPRI Payload field

The eCPRI Payload field depends on the message type used. See more in Specification.

History

It starts with CPRI and with upcoming 5G a new protocol was needed.

In August 2017 eCPRI Specification V1.0 was released.
In January 2018 eCPRI Specification V1.1 was released.
In June 2018 eCPRI Specification V1.2 (latest version) was released.

You find the latest versions here

Protocol dependencies

Ethernet: eCPRI uses Ethernet with the Ethertype 0xAEFE
UDP: eCPRI uses UDP as its transport protocol

Example traffic

The example shows an eCPRI tree with Message Type 5 in wireshark.

evolved Common Public Radio Interface
    eCPRI Common Header: 0x1005002a
        0001 .... = Protocol Revision: 1
        .... 000. = Reserved: 0
        .... ...0 = C-Bit: 0
        Message Type: One-Way Delay Measurement (0x05)
        Payload Size: 42
    eCPRI Payload: 11:00:00:00:45:b1:11:49:1c:41:78:f4:00:00:00:00:…
        Measurement ID: 0x11
        Action Type: Request (0x00)
        Time Stamp: 00:00:45:b1:11:49:1c:41:78:f4
            Seconds: 1169232201s
            Nanoseconds: 474052852ns
        Compensation Value: 12025856 = 183.500000ns
        User Data: dd:dd:dd:dd:dd:dd:dd:dd:dd:dd:dd:dd:dd:dd:dd:dd:…

Wireshark

The eCPRI dissector is in Development Release 3.1.0 and fully functional with the latest packet format.

Preference Settings

(XXX add links to preference settings affecting how PROTO is dissected).

Example capture file

SampleCaptures/ecpri.pcap

Display Filter

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

Show only the eCPRI based traffic:

 ecpri

Show only the eCPRI-messages with Message Type 0x00 (IQ Data):

 ecpri.type == 0x00

Capture Filter

Capture only the eCPRI based traffic:

 ecpri

External links

eCPRI eCPRI Specification V1.2

Discussion

Imported from https://wiki.wireshark.org/eCPRI on 2020-08-11 23:13:43 UTC