{"version":"2.1.296","anchor":"session-tunnel-mcp-serve-quietlivenesspings-and-stream-lost","canonical_anchor":"session-tunnel-mcp-serve-quietlivenesspings-and-stream-lost","heading":"Tunnels detect dead connections with numbered pings and reconnect","tier":"use","area":"Elsewhere","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.296\/e\/session-tunnel-mcp-serve-quietlivenesspings-and-stream-lost","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.296","markdown":"### Tunnels detect dead connections with numbered pings and reconnect\n\nSession and preview tunnels number their liveness pings, reconnect after a run of unanswered ones, and report dropped streams and oversized frames\n\n**What**\n\nA tunnel is the connection that carries a session or preview between your machine and a remote one. Claude Code checks it is still alive by sending small ping messages and waiting for replies.\n\n- Each ping now carries a sequence number, and replies are matched against it.\n\n- When `quietLivenessPings` is set and that many pings in a row go unanswered, the tunnel reconnects. The reconnect is enforced only when `livenessEnforce` is on.\n\n- Before, a single deadline was measured from the last activity on the connection.\n\n- `--session-tunnel` now passes `quietLivenessPings`.\n\n- The remote-tools liveness check can return a new `stream_lost` result, when the upload was accepted but the stream dropped before the deadline. Before, it could only report a miss at the deadline.\n\n- Hosted remote sessions now drop an incoming message with too many parts without reading it, and log one warning, `frame_too_many_members`.\n\n**Why**\n\nA tunnel that has gone quiet is noticed sooner and reconnected, and a dropped stream is reported as such. For users this should mostly show up as fewer stuck remote or preview connections.\n\n- Area: Elsewhere\n- Names: `--session-tunnel`\n- Tier: Use it now\n- Useful: 2\/5\n- Signal: 3\/5\n- Scope: individual\n- Heads-up: no"}