Re: Difference between digital phone and VOIP

[Anders <nospam@xxxxxxxxx>]

JoeRaisin wrote:
> But why does (Cable systems) digital work and VOIP has so many problems?
>
> We don't have any problems with DSL (assuming filters are properly
> applied) and as the name implies - that's digital also.

Even if you normally don't have any issues with your Internet
connection while surfing the web or emailing, you may run into
problems using VoIP.

This is because VoIP needs a constant stream of data to carry
the audio data. The voice data is chopped into "packets", each
packet holding maybe 50-100ms worth of audio, and sent on its way.
If some of those packets get lost, the system tries to "guess"
what should have been there, and that actually works pretty
good. The human brain also has a tendency to fill in the gaps so
most people don't even hear a few lost packets.
A control panel modem is not as forgiving.

The latency is also a result of this "packetizing". When a packet
leaves the VoIP-box, it comes to the router. The router needs to
receive the WHOLE packet to make sure the checksum is good before
it sends it on to the cable modem. The cable modem again needs
to get the whole packet before it moves on to the cable, and
so it goes for every piece of hardware between you and the
destination. You can get a feeling for how many "hops" you have
between yourself and a destination by opening a command prompt
and typing :
   tracert www.google.com
(or whatever destination).

Like someone else wrote in this thread, the voice streams
share the same bandwidth as all other data on the Internet.
If your YouTube video download halts for a second, you'll not
notice it because the pre-buffer for several seconds, but 1s gap
in a voice call is really annoying.

Some of the cable bundles allocate separate bandwidth for their
own VoIP, and there have even been rumors about them *limiting*
the bandwidth or intentionally dropping data when they detect
competing VoIP packets on their network. Thus it may appear as the
bundled VoIP works better than for example Vonage.

So the bottom line is that VoIP is designed for VOICE. Not the
bleeps and burps a control panel spits out when it communicates.
A panel designed for networking, bypassing the VoIP modem, will
work a whole lot better than one using VoIP as a POTS replacement.
Not to mention the possibilities of having direct remote access
to the panel and the ability to supervise the connection for
"free".

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