ADSL works over wet string (2017)
ADSL broadband is so tolerant of poor physical media that it can even function over a length of wet string, highlighting how robust the technology is when pushed far beyond its intended use. Commenters use this stunt to reflect on decades of squeezing more bandwidth out of aging copper—via ADSL, VDSL, G.fast and creative hacks like barbed wire or powerline networking—often delaying investment in fiber, especially in rural and legacy networks. They contrast this with newer fiber-to-the-home deployments and share anecdotes about unreliable copper lines, water ingress, and the trade-offs between upgrading infrastructure and relying on ever more sophisticated transmission protocols.
Technical notes on “wet string” ADSL
- Follow‑up blog post is mentioned for more detailed measurements.
- Touching the wet string is said to be mostly an electrical issue: added impedance and capacitance can disrupt the signal.
- If the pair also carries analog phone service, touching during ringing can give a noticeable shock, even though normal voltages are low.
Real‑world DSL and infrastructure quality
- Multiple stories of ADSL/VDSL lines heavily affected by water ingress: speeds collapsing during rain, trunk lines with degraded paper insulation, and telcos refusing to properly fix bad pairs.
- Some users report very poor ADSL speeds even today (a few Mbps), especially in rural or older areas.
- In contrast, others describe excellent experiences where small ISPs persistently push the incumbent operator to repair lines, resulting in quick fixes.
Copper vs. fiber, DOCSIS, and G.fast
- ADSL/VDSL are described as both impressive and problematic: they squeeze high speeds out of decaying copper, but that delays fiber rollout.
- Several comments blame DOCSIS and copper‑based approaches for making incumbents complacent, while praising FTTH builds (including rural co‑ops) where they exist.
- Debate over G.fast: one claim that only a single country has a significant deployment is challenged with examples from Germany, UK, and other operators; consensus is that deployments exist but are limited and being overtaken by FTTP upgrades.
- Policy decisions in multiple countries are criticized for choosing more copper/coax in the past instead of early nationwide fiber.
Improvised and historical media
- References to 100 Mbps Ethernet over barbed wire, and early DIY telephone networks over barbed‑wire fences and party lines.
- Anecdotes about “IP over tin cans and wet string” as a student project: resonances in the medium, trade‑offs between using the resonant frequency vs. staying away from it for more complex modulation.
- Comparisons to powerline networking, carrier pigeons with storage media, and the classic “station wagon full of tapes” as high‑bandwidth but high‑latency links.
Multi‑pair wiring and bonding
- Many homes have at least two copper pairs; historically used for second lines, fax, modems, or redundancy.
- Bonded ADSL can work, but is fragile when one pair degrades or when crosstalk is high; lab tests with coiled flat cable differed significantly from real‑world uncoiled deployments.
Fallback and repair considerations
- Question raised about using scavenged copper as wartime fallback; fiber is noted as patchable but requiring specialized fusion splicers rather than simple twisting.