Cable modem is no different than a DSL modem, right? ;) If it's an eMTA, it may have battery backup, though the operational default is to disable the Ethernet port after a few minutes to provide the maximum amount of dial-tone. Frank -----Original Message----- From: Owen DeLong [mailto:owen@delong.com] Sent: Monday, December 27, 2010 12:05 AM To: frnkblk@iname.com Cc: NANOG; Jared Mauch Subject: Re: Muni Fiber Last Mile - a contrary opinion On Dec 26, 2010, at 7:35 PM, Frank Bulk - iName.com wrote: <snip>
You are likely already at the mercy of some local hut for your dialtone. Very few things home run to the co these days. It's unlikely any hut has more than 24 hours of battery.
I know this is true where FTTN overlays have been built. However, in the majority of California, at least, that is still more the exception than the rule and there is usually a Cat-3 Copper home-run for local dialtone.
[Frank Bulk] Here in the midwest each and every of the telcos that I've talked to or worked with feeds dialtone for their DSL customers from the same equipment that serves the DSL. To do otherwise would require a splitter shelf in each node.
In California, that is, by and large, the CO. <snip>
However, 24 hours of dialtone after something happens still exceeds the average cablemodem duration after the power flickers.
[Frank Bulk] Some MSOs (including ourselves) have power systems (e.g. Alpha) in place throughout the plant to provide backup power for at least some time.
Does that back up the cablemodem in the residence? If not, game over. Owen