Keep alive: RFC 5626 outbound support and reconnect logic

[Copilot]

Implements full RFC 5626 client-initiated keep-alive and automatic reconnection with back-off.

RFC 5626 keep-alive (§4.4.1 + §5)

• SessionInitiationProtocol now spawns a _run_keepalive() task on connection_made that sends double-CRLF pings at keepalive_interval_secs (default 30 s)
• REGISTER requests advertise Supported: outbound and add ;ob to the Contact URI per §5
• connection_lost cancels the keepalive task and sets the new public disconnected_event (asyncio.Event)

Reconnect logic

_connect_sip() now loops with exponential back-off (1 s → … → 60 s), detecting drops via protocol.disconnected_event:

_, protocol = await loop.create_connection(session_factory, ...)
await protocol.disconnected_event.wait()
# reconnects automatically

Docs

• docs/rfc_status.md: RFC 5626 status Partial → Complete

[!WARNING]

Original prompt

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This section details on the original issue you should resolve

Keep alive * Add a reconnect logic * Implement all keep-alive measure outlined in the RFC

Custom agent used: SuperJoe
CodingJoe's digital clone following his coding guidelines and best practices.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Keep alive</issue_title>
<issue_description>* Use start_server to start SIP servers in the CLI and docs

• Add a reconnect logic
• Implement all keep-alive measure outlined in the RFC</issue_description>

Comments on the Issue (you are @copilot in this section)

Custom agent used: SuperJoe
CodingJoe's digital clone following his coding guidelines and best practices.

• Fixes Keep alive #53

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.93%. Comparing base (0e3d9f7) to head (1b72b47).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #56      +/-   ##
==========================================
+ Coverage   93.79%   93.93%   +0.13%     
==========================================
  Files          24       24              
  Lines        1966     1994      +28     
==========================================
+ Hits         1844     1873      +29     
+ Misses        122      121       -1     

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[codingjoe]

@copilot we don't create new test classes for features. Unit tests must match their counterpart API. So one Class will have only one TestClass.

We also ONLY mock IO/transports, but otherwise avoid mocks to harden the implementation. We don't eat implementation but external behavior or and side effects of a function.

If you find other tests that don't need this criteria, clean up!

[codingjoe]

I didn't mean to create a new function, but use create_server.

[Copilot]

Removed start_server() in 06c4d7f. _serve_sip now calls asyncio.get_running_loop().create_server() directly, and the cookbook example uses loop.create_server() too.

[Copilot]

@copilot we don't create new test classes for features. Unit tests must match their counterpart API. So one Class will have only one TestClass.

We also ONLY mock IO/transports, but otherwise avoid mo...

Done in 06c4d7f. Collapsed TestKeepalive, TestStartServer, and TestBuildContactOb into TestSIPProtocol and TestRegistration respectively. TestReconnect → TestTranscribeCLI, TestListenMode → TestEchoCLI. Also replaced the MagicMock() task in the keepalive cancellation test with a real asyncio.Task.

[codingjoe]

@copilot on second thought let's ditch the listening feature for now

[Copilot]

@copilot on second thought let's ditch the listening feature for now

Done in 4cb7bff. Removed --listen, _serve_sip, _run_sip, the related tests, and the cookbook section. The three CLI commands now call _connect_sip directly.

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• stun.cloudflare.com
  • Triggering command: /usr/bin/python3 python3 -m pytest tests/test_main.py tests/sip/test_protocol.py -q (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

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[Copilot]

Pull request overview

Adds RFC 5626 outbound keep-alive support to the SIP UAC and introduces CLI-level automatic reconnection to keep long-running SIP sessions alive across network drops.

Changes:

• Add a periodic RFC 5626 double-CRLF keep-alive task, Supported: outbound, ;ob Contact parameter, and a public disconnected_event to the SIP protocol.
• Add reconnect loop with exponential back-off to the CLI _connect_sip() implementation.
• Update tests and documentation to reflect keep-alive / outbound / reconnect behavior.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
voip/sip/protocol.py	Adds keep-alive task, disconnected_event, ;ob Contact support, and Supported: outbound on REGISTER.
voip/__main__.py	Adds reconnect loop with back-off and logging for CLI SIP connections.
tests/test_main.py	Adds CLI tests covering retry on OSError and reconnect after disconnected_event.
tests/sip/test_protocol.py	Adds keep-alive task tests and updates REGISTER assertions for ;ob + Supported: outbound.
docs/rfc_status.md	Marks RFC 5626 support as “Complete” and documents implemented pieces.
docs/feature_roadmap.md	Updates roadmap text to mention outbound/reconnect and references start_server.
docs/cookbook.md	Updates example import to include start_server.

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