FINDING · EVALUATION

Reproducing Zohaib et al.'s 10-payload QUIC parser test suite against Russian TSPU devices reveals that the Russian QUIC parser differs meaningfully from the GFW: payload 8 (PING and PADDING frames inserted before the Crypto frame), which circumvents the GFW, does not bypass Russian censorship. Payload 10 (QUICv2) bypasses both censors. Payload 9 (ECH with outer SNI cloudflare-ech.com) is blocked by Russia; payload 3 (version bytes 0x00000002 with invalid MAC) is blocked by both.

From 2026-heitmann-russia-s-early-introduction — On Russia’s Early Introduction of QUIC SNI Censorship · Appendix B, Table 2 · 2026 · FOCI 2026

Implications

Do not port GFW QUIC circumvention techniques directly to Russia without independent validation; the TSPU QUIC parser has distinct implementation differences that cause techniques effective against the GFW to fail against TSPU.
ECH with a fronting SNI is blocked by Russian TSPU; concealing the inner SNI via ECH alone is insufficient for Russia and must be combined with a transport that does not expose the ECH extension to the TSPU parser.