Seyd over Starlink

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Best-judgment assessment (2026-08-31), grounded in field runs A/B and current public information about Starlink’s network. Not yet tested on real hardware.

The question that decides everything

Same as field run B: can an unsolicited inbound packet reach the robot’s QUIC port (UDP 4433)? The pilot is a browser, i.e. a QUIC client, so only the robot must be reachable; the pilot’s own network only makes outbound connections and never needs to be open. So “both ends on Starlink” is no harder than “robot on Starlink” — it comes down entirely to the robot’s inbound reachability.

What Starlink gives you

	Residential / Roam / Mobile	Priority / Business (incl. Mobile Priority)
IPv4	CGNAT, no public IPv4, no inbound	Public IPv4 available as an add-on (~$140+/mo); removes CGNAT
IPv6	Global, routable /56 via DHCPv6-PD — every device gets a public address, no NAT	Same
Stock router (Gen 2 / Gen 3 / Business)	No port forwarding, no IPv6 firewall pinhole — on any tier	Same

Two facts from this that matter most:

1. No Starlink-issued router supports the inbound port-forward / IPv6 pinhole we need — on any plan. The tiers differ in addressing (the public-IPv4 add-on), not in router capability. So the answer to “does a higher tier come with a router that has the support we need” is no; the differentiator is the public-IP add-on, plus what you put behind the dish.
2. IPv6 is native and global on every tier, including residential. That is the cheap escape hatch — but IPv6 removes the NAT, not the firewall, and the stock router will not open an inbound hole. As run B proved, an inbound pinhole is still required.

Two ways to make a Seyd robot on Starlink reachable

Path A — IPv6, any plan (cheapest). Put the Starlink router in Bypass Mode and run your own router (UniFi, MikroTik, pfSense, Firewalla) that requests the /56 prefix delegation and adds an inbound IPv6 firewall rule for UDP 4433 to the robot. Works on plain Residential because the global /56 is universal. Cost: a ~$100–200 router, no plan upgrade. Catch: the pilot must also have IPv6 (a browser on an IPv4-only network cannot use a v6 candidate). Seyd already advertises the robot as a host6 candidate; this is exactly the path that lit up behind the 4G router in run B once the firewall let it in.

Bypass Mode is an official, supported Starlink feature — a toggle in the Starlink app that turns the Starlink router into a pass-through (Wi-Fi and routing off) so your own router does the work. It is reversible and not a hack. Hardware caveat by dish generation: the round Gen 2 dish has no LAN port of its own, so bypass mode needs the official Starlink Ethernet Adapter (~$25) to connect your router; the Gen 3 dish (and the Business/Flat High Performance units) has Ethernet built in, so no adapter is required.

Path B — public IPv4, works for any pilot. Take a Priority / Business plan with the public-IP add-on (~$140+/mo). That gives a normal public IPv4; forward UDP 4433 to the robot (still via bypass mode + your own router, or via whatever inbound the public-IP config allows). This reaches IPv4-only pilots too, so it is the choice when you don’t control the pilot’s network.

Neither available → relay tier. A stock-router residential Starlink with an IPv4-only pilot is genuinely unreachable directly — a relay-tier customer.

Will the link quality hold?

Yes, and Starlink plays to Seyd’s strengths. LEO base latency is ~20–50 ms one way (fine for teleoperation), but satellite handovers every ~15 s cause brief latency spikes and bursty loss — the same profile we exercised on cellular in runs A/B. The mitigations are all in: per-block FEC recovers without a round trip, the adaptive close-out deadline turns handover jitter into patience rather than fake loss, the ABR raises parity to 50 % under loss and trims bitrate on RTT inflation, and keyframe-on-loss caps a smear at one round trip. Residual risk: a handover burst longer than the delta parity shows a brief red border and a fast recover — the honest behaviour. One real gap: re-gathering candidates on a network change is still a stub, and a Starlink prefix/IP can change, so a long-lived robot needs that (already on the roadmap), plus port-mapping renewal.

Bottom line

Robot placement	Pilot	Direct P2P?
Starlink, stock router	any	No → relay
Starlink, bypass + own router, IPv6 pinhole, any plan	has IPv6	Yes (host6)
Starlink, Priority/Business public-IPv4 + forward 4433	any	Yes (portmap/host)
Both ends on different Starlinks	—	Same as robot-only (pilot side is client-only)

Confidence: high — residential global /56 IPv6 and the stock-router limitation are consistently confirmed across multiple 2026 sources. The cloud prober (the inbound_ok measurement done by hand in run B) is what would turn this into a per-install answer at enrolment instead of at the first session.

Sources: Starlink Help Center “What IP address does Starlink provide?”; satspeedcheck.com CGNAT-bypass guide (2026); Llama Networks “Starlink IP Addressing”; CellStream “Does Starlink support IPv6?”; packetville.net self-hosting-behind-Starlink-with-IPv6.