AS9664 SATPL-AS-AP SOUTHEAST ASIA TELECOMSG PTE. LTD.

AS9664 (SATPL-AS-AP) is held by SOUTHEAST ASIA TELECOM (SG) PTE. LTD., a Singapore-registered telecoms company associated with the SEATEL group, which holds mobile and ISP interests around the ASEAN region. The AS behaves as an eyeball network: its address space carries residential fibre subscribers, not transit or hosting.

What it's used for

The IPv4 footprint is almost vestigial and the IPv6 footprint is not. RIS sees 3 IPv4 prefixes totalling 1,024 addresses against 19 IPv6 prefixes — mostly /36s out of 2401:f1e0::/36 and 2400:9ce0::/36, plus a 2001:df3:3fc0::/48 — announced through 18 observed neighbours.

That inversion is the interesting part. A residential ISP starting from a 1,024-address IPv4 base cannot give every subscriber a public v4 address, so the v4 space serves gateways and infrastructure behind carrier-grade NAT while customers get real IPv6. Sampled reverse DNS on 163.61.198.0/24 returns names of the form 163-61-198-5.home-fiber.auk.sg — the per-subscriber naming of a home-fibre product marketed in Singapore under the AUK brand, living inside this AS's space.

The prefixes are geographically split: two Singapore blocks and 162.4.174.0/23, which is registered against Cambodia. That is consistent with a group holding operations in more than one ASEAN market rather than with a scattered, unrelated inventory.

Notable

• Nineteen IPv6 prefixes to three IPv4 ones is the routing profile of an operator that built for v6 because it never had enough v4 to build otherwise.
• Eighteen neighbours on a small address count is peering breadth, not transit scale; the traffic terminates at subscribers.