[152563] in North American Network Operators' Group
VoIP vs POTS (was Re: Operation Ghost Click)
daemon@ATHENA.MIT.EDU (Jared Mauch)
Wed May 2 16:16:08 2012
From: Jared Mauch <jared@puck.nether.net>
In-Reply-To: <C262B52114110B4586FAF49F074F0580109897F1D6@mailserver2007.nyigc.globe>
Date: Wed, 2 May 2012 16:15:26 -0400
To: Eric Wieling <EWieling@nyigc.com>
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On May 2, 2012, at 3:52 PM, Eric Wieling wrote:
>=20
> I doubt the g729 or GSM codecs used by VoIP and Cell phones can =
compare to a POTS line.
This is why many people use g711ulaw or other codec.
Personally I would not work with anyone that doesn't do g711ulaw =
(88.2kbit when IP packet overhead added in).
There are other codecs such as G.722.1 & G.722.2 but the support isn't =
as broad as g711ulaw/alaw.
Regarding landline service, this can fail for many of the common reasons =
it does are the same reasons that IP service may fail. The failure =
modes can depend on a variety of circumstances from the physical layer =
(e.g.: audible static on the line) that cause your ear to retrain, which =
may cause a DSL device to comparably retrain. The same is true for =
shared medium such as CATV but this has other problems as well, if not =
well isolated, somebody can short out the segment or send garbage at the =
wrong channel, etc.
Personally, I'm thinking of ditching my ISDN (gives clear dial tone at a =
long-distance from the CO) for something like the Verizon Home Connect =
box. Gives a few hours of built-in battery backup, but would fail once =
the tower loses power (usually 8-12 hours).
I also am concerned about 911 service. When dialing 911 recently from =
my mobile, I should have dialed it from my home phone as I was routed a =
few times to get to the right fire dispatch team.
Oh well.
- Jared=
