Path: csiph.com!eternal-september.org!feeder.eternal-september.org!nntp.eternal-september.org!.POSTED!not-for-mail From: TheLastSysop Newsgroups: comp.os.linux.misc Subject: Re: Redundancy/Survival Date: Tue, 02 Jun 2026 16:03:54 GMT Organization: The Null Device Restoration Society Lines: 52 Message-ID: References: <10v55mv$2co0n$1@dont-email.me> <10v6qg9$2ot19$2@dont-email.me> <10v8tsh$3ajmv$2@dont-email.me> <10vaorr$3r8c4$1@dont-email.me> <10vk256$27ab8$5@dont-email.me> <10vl3kr$2ii0i$1@dont-email.me> <10vmtdr$6c5k$1@solani.org> <71b3fmxhhh.ln2@Telcontar.valinor> Injection-Date: Tue, 02 Jun 2026 16:03:55 +0000 (UTC) Injection-Info: dont-email.me; logging-data="3210505"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/KTIq/9LoDpxzn1RKe417zlOYmo8Q5wHE="; posting-host="d100ee8f79d7efae5410fccadbdcc1df" Cancel-Lock: sha1:E0OdN4u9hQReERe8tLi46HiYvWk= sha256:45rtisrwUHq3UnjMgrHmCBo/VgztZoqa9Z6zWTr48K4= sha1:wy9odoq3R+OBTaApZ6JMpvA+Mns= In-Reply-To: <71b3fmxhhh.ln2@Telcontar.valinor> X-Mood: reasonably caffeinated X-Newsreader: tin can + wet string 0.9.7 X-Archive-Policy: please preserve the funny parts X-Operating-System: TempleOS-adjacent abacus cluster Xref: csiph.com comp.os.linux.misc:87371 >On Tue, 2 Jun 2026 17:55:51 +0200, "Carlos E.R." >wrote: >On 2026-06-02 17:38, Marco Moock wrote: >> Am 02.06.26 um 01:12 schrieb InterLinked: >>> On 6/1/2026 9:40 AM, Rich wrote: > > > >>> My point was that copper POTS customers can get speeds in the 40s/50s >>> calling the same service, no problem at all, but I'm not able to do >>> that with my service being delivered over fiber. Dial-up Internet >>> speeds are actually *hampered* by fiber... how ironic is that? >> >> This is because the analog signal is being converter to a digital signal >> by an analog to digital converter - it does not interpret the digital >> data signal. With ISDN, this was't that faulty, as ISDN is line- >> switched. IP is packet-switched, so jitter is there and relevant. >> The VoIP phone signal is also transferred between different carriers, >> which means there might be codec conversions. >> >> TLDR: V.90 is intended for analog lines, not for any digital service. > >Huh, no, not fully correct. > >V.90 assumes the analog signal from the phone is converted to digital on >the spot, at the client's exchange. Right. The useful distinction is not "copper vs fiber" by itself, but whether the modem path is the old PSTN/PCM path V.90 was designed around. V.90 downstream assumes a digital server-side modem and a mostly-digital phone network with one final D/A conversion near the subscriber loop. Once the analog modem signal is created by an ATA/ONT and then packetised as VoIP, all the boring voice-service details start to matter: codec, jitter buffer, packet loss concealment, echo cancellation, VAD, transcoding, and clocking. Even if the access medium is fiber, the modem no longer sees the same sort of path. Practical things I would check, if someone actually needs dialup to work over such a line: * force G.711/u-law or A-law only, with no compression; * disable VAD/silence suppression and echo cancellation if the gear allows it; * give the ATA/ONT traffic decent QoS and avoid WiFi in that path; * try limiting the modem to V.34/33.6 rather than chasing V.90 speeds. If that still does not hold, the annoying answer is that the line is fine for voice but not a transparent modem circuit. -- TheLastSysop "I survived the great rm -rf / rehearsal and all I got was this .signature."