Wireshark with the omci.lua and BinDecHex.lua plug-ins installed.

In devices like the SFP module G-010S-A or the 1-port ONT G-010G-A, it is possible to capture OMCI messages, which can be useful in troubleshooting performance problems. In the SFP module, this function is only possible with the latest firmware versions, like 3FE46398BGCB22.

After powering up and synchronizing with OLT, the device creates an omcimsg.txt file in the /tmp folder. This file is eventually deleted after a few minutes or overwritten with periodic diagnostic data. The file capturing the initial OMCI exchange should be 25KB-90KB in size. If it is not there or is very small, it is still possible to force an OMCI exchange by unplugging the green fiber connector and plugging it back in while the device is powered on. This should create a new omcimsg.txt file, which should be retrieved rather quickly.

Sample log retrieved from the device

OMCI_RX#   1@   1m:58s: 437ms-80 01 49 0A 00 02 00 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 28 C0 CB C4 82 
OMCI_TX#   1@   1m:58s: 511ms-80 01 29 0A 00 02 00 00 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
OMCI_RX#   2@   1m:58s: 607ms-80 02 49 0A 00 02 00 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 28 F6 CF 92 2B 
OMCI_TX#   2@   1m:58s: 627ms-80 02 29 0A 00 02 00 00 00 80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

To convert log to hex format readable by Wireshark

awk -F"ms-" '{print$2}' omcimsg.txt | sed -e 's/^/000000 /' > omci.hex

To open the file omci.hex in Wireshark

File -> Import from Hex Dump
Encapsulation Type -> Ethernet
set Ethernet -> Ethertype (hex): 88b5
Import