OpenOLT agent

The OpenOLT agent runs on white box Optical Line Terminals (OLTs) and provides a gRPC-based management and control interface to OLTs.

The OpenOLT agent is used by VOLTHA through the OpenOLT adapter.

OpenOLT agent uses Broadcom’s BAL (Broadband Adaptation Layer) software for interfacing with the Maple/Qumran chipsets in OLTs such as the Edgecore/Accton ASXvOLT16.

  |             VOLTHA              |
  |                                 |
  |       +------------------+      |
  |       | OpenOLT adapter  |      |
  OpenOLT gRPC API |
+--------------------- ---------------+
|                  |                  |
|         +------------------+        |
|         |   OpenOLT agent  |        |
|         +--------+---------+        |
|                  |                  |
| Vendor specific  | (e.g. Broadcom   |
|       API        |     BAL API      |
|                  |                  |
|         +------------------+        |
|         | Vendor SoC/FPGA  |        |
|         |(e.g Maple/Qumran)|        |
|         +------------------+        |
|                                     |
|           White box OLT             |

Hardware requirements

A list of tested devices and optics can be found in the CORD hardware requirements guide, in the R-CORD access equipment and optics section.

Pre-built debian packages of OpenOLT agent for Accton/Edgecore ASFVOLT16/ASGvOLT64

Accton/Edgecore makes available pre-built debian packages of OpenOLT agent to their customers. Get access credentials for and then login and navigate to File_Station -> EdgecoreNAS, and then the folder /ASXvOLT16/OpenOLT_Agent/From_ONF_Distribution/ and pick the right version of .deb package required for your testing.

voltha-2.3/openolt_<OPENOLTDEVICE>-2.3.0-<Last Commit ID>.deb is the latest version of package with support for BAL v3.4.3.3 .

The pre-built debian packages have been tested on Open Networking Linux (ONL) version 4.14. The ONL Installer required for voltha-2.3/openolt_<OPENOLTDEVICE>-2.3.0-<Last Commit ID>.deb is also available at in the same path, i.e., voltha-2.3/.

Install OpenOLT

Copy the debian package to the OLT. For example:

scp openolt.deb root@

Install the openolt.deb package using dpkg:

dpkg -i openolt_<OPENOLTDEVICE>-2.3.0-<Last Commit ID>.deb

The ONL version required for BAL v3.4.3.3 is ONL 4.14.151-OpenNetworkLinux. This will be built as part of build procedure described Build OpenOLT section.

Run OpenOLT as a Linux service

Rebooting the OLT (after the installation) will start dev_mgmt_daemon and openolt as system services:


The services can also be stopped/started manually:

service dev_mgmt_daemon stop
service openolt stop
service dev_mgmt_daemon start
service openolt start

Check the status of the services:

service dev_mgmt_daemon status
service openolt status

Run OpenOLT in foreground for development and debugging

Running the dev_mgmt_daemon and/or openolt services in the foreground is useful for development and debugging. Make sure to first stop the services if they are running in background.

service dev_mgmt_daemon stop
service openolt stop

Open a terminal and run the Broadcom BAL software (dev_mgmt_daemon):

cd /broadcom
./dev_mgmt_daemon -d -pcie

The dev_mgmt_daemon executable presents the CLI for Broadcom’s BAL when run in the foreground which is useful for debugging.

While the first executable still runs (even in background), open another terminal and run openolt:

cd /broadcom
./openolt --interface <interface-name> (or)
./openolt --intf <interface-name>


  • In the commands above, you should specify OLT management interface name or inband interface name if OLT is used in inband mode. Openolt gRPC server will start listening on given interface’s IP address. If no interface specified gRPC server will listen on “” which will accpet requests from any of the interfaces present in OLT.

  • The two executables will remain open in the terminals, unless they are put in background.

Inband ONL Note

  • Inband ONL image built by packaging Openolt debian package and some startup scripts. The startup scripts serve to enable inband channels, create inband tagged interfaces, install Openolt debian package and run dev_mgmt_daemon and Openolt services.

  • Startup script named “” will be executed in background after ONL installation. Script execution could be watched in a log file located in /var/log/startup.log.

  • Follow the procedure specified below in Build OpenOLT section to build integrated Inband ONL image.

Connect from VOLTHA

At the VOLTHA CLI, preprovision and enable the OLT:

(voltha) preprovision_olt -t openolt -H YOUR_OLT_MGMT_IP:9191
(voltha) enable

Additional notes

  • 9191 is the TCP port that the OpenOLT agent uses for its gRPC channel.

  • In the commands above, you should use OLT inband interface IP address if OLT is used in inband mode, otherwise substitute all its occurrences with the management IP of your OLT.

Log Collection for whitebox OLT Device

To collect logs from openolt, dev_mgmt_daemon and syslog processes install td-agent(fluentd variant) directly on OLT device which will capture and transmits the logs to elasticsearch pod running in voltha cluster.


OLT should have ntp installed to ensure it has correct time(which is used by td-agent for generated events)

apt-get install ntp

Installation of td-agent deb package:

  • Download the deb package for td-agent

  • Install td-agent on device

dpkg -i td-agent_3.8.0-0_amd64.deb

Post Installation:

We have created custom td-agent configuration file to handle format of involved log files using right input plugins and elasticsearch output plugin.

Copy the custom config file from here in the ~ directory of the olt. Then into the /etc folder in order for the agent to pick it up.

cp td-agent.conf /etc/td-agent.conf
  • Set elasticsearch host and port in /etc/td-agent.conf

  • Restart the td-agent service

service td-agent restart

Need to redirect syslog to default port of fluentd syslog plugin.

  • Add “. @” to /etc/rsyslog.conf

  • Restart syslog using

/etc/init.d/rsyslog restart


To enable TLS encryption features with td-agent look at this google doc

Build OpenOLT

Supported BAL API versions

Currently, OpenOLT supports Broadcom’s BAL API, version

Proprietary software requirements

The following proprietary source code is required to build the OpenOLT agent.

  • SW-BCM686OLT_<BAL_VER>.tgz - Broadcom BAL source and Maple SDK

  • sdk-all-<SDK_VER>.tar.gz - Broadcom Qumran SDK

  • ACCTON_BAL_<BAL_VER>-<ACCTON_VER>.patch - Accton/Edgecore’s patch

The versions currently supported by the OpenOLT agent are:

  • SW-BCM686OLT_3_4_3_3.tgz

  • sdk-all-6.5.13.tar.gz

  • ACCTON_BAL_3.4.3.3-V202002100101.patch

NOTE: the repository does not contain the above three source packages. These are needed to build the OpenOLT agent executable. Contact Dave Baron at Broadcom to access the source packages.

System Requirements

Hardware :

CPU: Dual-core (4 Threads) up.

Memory: 6GB

Storage: 40GB of free space.

Software :

  1. OpenOLT agent builds on Ubuntu 16.04 LTS.

  2. At least 4G of ram and 4G of swap - compilation is memory intensive

  3. Essential tools for building packages

    sudo apt-get install build-essential ccache

  4. Install cmake version 3.5.0 or above. Download cmake-3.5.0.tar.gz and untar it, then in the cmake-3.5.0 directory install by running:

    ./bootstrap && make && make install

Build procedure

Clone the openolt repository either from OpenCORD Gerrit:

git clone

Copy the Broadcom source and patch files to the openolt/agent/download directory:

cd <dir containing Broadcom source and patch files>
cp ACCTON_BAL_3.4.3.3-V202002100101.patch SW-BCM686OLT_3_4_3_3.tgz sdk-all-6.5.13.tar.gz <cloned openolt repo path>/agent/download

Run the configure script to generate the appropriate Makefile scaffolding for the desired target:

cd openolt/agent

Run make prereq to install the package dependencies. This is usually a one-time thing, unless there is a change in the dependencies.

make OPENOLTDEVICE=asfvolt16 prereq

Run make. This can take a while to complete the first time, since it builds ONL and the Broadcom SDKs. Following runs will be much faster, as they only build the OpenOLT agent source.

make OPENOLTDEVICE=asfvolt16

Note that the required ONL version 4.14 is built as part of the above build procedure and is available at path build/onl/OpenNetworkLinux/RELEASE/jessie/amd64/ONL-onl-4.14_ONL-OS8_2020-01-30.0413-72b95a7_AMD64_INSTALLED_INSTALLER. This ONL Installer should be used to flash the OS on the OLT.

If you need to use a specific version of voltha-protos, then specify the git tag/branch corresponding to that specific version:


By default, the OPENOLT_PROTO_VER defaults to git tag v3.3.6 of the voltha-protos repo.

If the build process succeeds, libraries and executables will be created in the openolt/agent/build directory.

Optionally, build the debian package that will be installed on the OLT.

make OPENOLTDEVICE=asfvolt16 deb

If the build process succeeds, a .deb package will be created as well in the openolt/agent/build directory.

Run make with inband option as specified below to build all-in-one ONL image packed with Openolt debian package and Inband OLT startup scripts(Scripts to enable Inband channel and start dev_mgmt_daemon and openolt services). This can take a while to complete the first time, since it builds ONL and the Broadcom SDKs. Following runs will be much faster, as they try to build OpenOLT agent source and Inband ONL with modified Openolt deb package.


If no VLAN_ID is specified in above command it defaults to 4093.

Note that the required INBAND ONL version 4.14 is built as part of the above build procedure and is available at path build/onl/OpenNetworkLinux/RELEASE/jessie/amd64/ONL-onl-4.14_ONL-OS8_2020-04-22. 2206-b4af32e_AMD64_INSTALLED_INSTALLER\. This ONL Installer should be used to flash the OS on the OLT.

NOTE: To compile for ASGvOLT 64 port GPON OLT, set OPENOLTDEVICE to asgvolt64 during build procedure like below.

make OPENOLTDEVICE=asgvolt64


To cleanup the repository and start the build procedure again, run:

# cleans up the agent objects, protos compiled artificats and openolt deb packages
make OPENOLTDEVICE=asfvolt16 clean

# cleans up the agent objects, protos compiled artificats, openolt deb packages and bal sources
make OPENOLTDEVICE=asfvolt16 distclean


The information here may be specific to specific OLT and ONU hardware such as Edgecore ASFVOLT16 OLT and Broadcom based ONUs.

How to change speed of ASFVOLT16 NNI interface?

Auto-negotiation on the NNI (Network to Network Interface) uplink ports is not tested.

By default, the OpenOLT agent sets the speed of the NNI interfaces to 100G. To downgrade the network interface speed to 40G, add the following lines at the end of the /broadcom/qax.soc configuration file.

port ce128 sp=40000

A restart of the dev_mgmt_daemon and openolt services is required after making this change.

Why does the Broadcom ONU not forward eapol packets?

The firmware on the ONU is likely not setup to forward 802.1x EAPOL traffic on the Linux bridge. Drop down to the shell in the Broadcom ONU’s console and configure the Linux bridge to forward 802.1x.

> sh
# echo 8 > /sys/class/net/bronu513/bridge/group_fwd_mask

Version 1.7 of VOLTHA has a known issue where the ONU is only able to pass EAPOL packets from a specific LAN port (e.g. LAN port 1 on ALPHA ONUs)

How do I check packet counters on the ONU?

LAN port packet counters:

bs /b/e port/index=lan{0,1,2,3,4,5,6}

WAN port packet counters:

bs /b/e port/index=wan0

How to get access to MAPLE CLI on OLT box

To get access to the BCM.0> maple console, SSH into the OLT and then execute:

cd /broadcom

How do I check packet counters on the OLT’s PON interface?

Following is an example of retrieving the interface description for PON intf_id 0

(TODO: document PON interface numbering for Edgecore OLT).

BCM.0> a/t clear=no object=pon_interface sub=itu_pon_stats pon_ni=0
[-- API Start: bcmolt_stat_get --]
[-- API Message Data --]
object: pon_interface- PON Network Interface.
get stat subgroup: itu_pon_stats-ITU PON Statistics. loid: 0 response: OK
[-- API Complete: 0 (OK) --]

How do I check packet counters on the OLT’s NNI interface?

Following command retrieves NNI intf_id 0:

BCM.0> a/t clear=no object=nni_interface sub=stats id=0
[-- API Start: bcmolt_stat_get --]
[-- API Message Data --]
object: nni_interface- nni_interface.
get stat subgroup: stats-NNI Interface Statistics. loid: 0 response: OK
[-- API Complete: 0 (OK) --]

How do I list flows installed in the OLT?

Following command lists the flows installed on the OLT.

BCM.0> a/m max_msgs=100 filter_invert=no object=flow

How do I access device CLI when running dev_mgmt_daemon and openolt agent binary as services?

Navigate to /opt/bcm68620 and execute the command /broadcom/dev_mgmt_attach to access the QAX diagnostic shell. If you are not able to access the shell, you need to recompile the BAL SDK with SW_UTIL_SHELL=y option set.

Known Issues

  • The Minimum BW that should be configured for ITU PON Alloc Object has changed from 16Kbps to 32Kbps from BAL3.1 to BAL3.2 release if you are using ALPHA ONUs. As per BAL3.x documents, when FEC is disabled, the minimum BW is 16Kbps on the ITU PON Alloc Object. This seems to be a discrepancy on the ALPHA ONU. So, ensure that cir + eir value is greater than equal to 32000 for XGSPON use case for ALPHA ONU.