Retry confirmed class C downlink on timeout

[halimi]

Summary

The NS resends the class C confirmed downlink after the mac_settings.class_c_timeout time.

When the NS sends a confirmed downlink to a class C device then the device should send an uplink within the mac_settings.class_c_timeout. If no uplink has arrived within the timeout then the NS sends a NACK to the AS and the AS resends the downlink message again maximum 8 times and after that drops it.

Changes

• Add a new task runner for the pending downlink messages.
• NS adds a task to the pending downlink queue if there is a pending downlink.
• The pending downlink task reschedules the pending downlink message after the timeout.

Testing

Steps

Set a short value for the mac_settings.class_c_timeout (e.g. 30 sec), it should be less than the period how the end device sends the uplinks (e.g. 5 min).

Send a confirmed downlink message to a class C device.

• If the end device doesn't send an uplink within the timeout then the NS should resend the pending downlink again until either it reaches the maximum retry number, which is 8 or the end device sends an uplink with an ACK.
• If the end device sends an uplink within the timeout but without an ACK then the NS should resend the pending downlink.
• If the end device sends an uplink within the timeout with an ACK then the NS shouldn't resend the pending downlink.

Send more than one confirmed downlink to a class C device.

• The NS should put back the pending downlink to the downlink queue for resending.

Results

I've tested it on my test env and it works as expected.

---

• If the end device doesn't send an uplink within the timeout then the NS should resend the pending downlink again until either it reaches the maximum retry number, which is 8 or the end device sends an uplink with an ACK.

• If the end device sends an uplink within the timeout but without an ACK then the NS should resend the pending downlink. (The class_c_timeout was set to 7 min)

• If the end device sends an uplink within the timeout with an ACK then the NS shouldn't resend the pending downlink. (The class_c_timeout was set to 7 min)

---

Send more than one confirmed downlink to a class C device.

• The NS should put back the pending downlink to the downlink queue for resending.

Regressions

...

Notes for Reviewers

@PavelJankoski @ryaplots The mjml node package has been updated #7720 and now it generates a different file for the email templates base.html.tmpl. I had to regenerate the golden files otherwise the go tests are failing. Could you please review the new template file changes?

Checklist

• Scope: The referenced issue is addressed, there are no unrelated changes.
• Compatibility: The changes are backwards compatible with existing API, storage, configuration and CLI, according to the compatibility commitments in README.md for the chosen target branch.
• Documentation: Relevant documentation is added or updated.
• Testing: The steps/process to test this feature are clearly explained including testing for regressions.
• Infrastructure: If infrastructural changes (e.g., new RPC, configuration) are needed, a separate issue is created in the infrastructural repositories.
• Changelog: Significant features, behavior changes, deprecations and fixes are added to CHANGELOG.md.
• Commits: Commit messages follow guidelines in CONTRIBUTING.md, there are no fixup commits left.

[johanstokking]

Okay this is great stuff. Can you confirm this works well locally after the last commit too?

[halimi]

Okay this is great stuff. Can you confirm this works well locally after the last commit too?

I pushed one more cleanup commit, it was a leftover from the previous implementation. I'm running the tests on this last commit and it looks good until so far. I will update the test results.

[halimi]

I've tested it on my local test env and it works as expected. I've updated the test results images.

[ryaplots]

template file changes look good

[nicholaspcr]

LGTM