[time-nuts] Frequency from telco

Poul-Henning Kamp phk at phk.freebsd.dk
Sun Sep 24 19:30:55 EDT 2006

In message <0609242322.AA00795 at ivan.Harhan.ORG>, Michael Sokolov writes:
>Hal Murray <hmurray at suespammers.org> wrote:

>> Does anybody know how DSL works?  If I poke around with a scope in my DSL 
>> modem/router, will I find a clock locked to the telco's master clock?
>I doubt it.  DSL lines come from DSLAMs, not from "real" telco equipment

It's more complicated than that.  Most DSLAMs can are hooked
into the network sync because people once thought they would
also be used to deliver isochronous services like voice.

However, the CPE ("modem") in your end, has absolutely zero clue
about this.

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

More information about the time-nuts mailing list