[ILUG] Help needed with VOIP & Digital Phone

[Alan Ryan]

Hi Colin,

I also am "condemned to mobile broadband for use at home"

I had thought of this when I was ringing support, they didn't seem too
bothered about me talking about VOIP.  I could see  why they would try and
restrict it's usage alright - but that's a rant for another post.

Thanks,
Alan

2009/3/7 Colin Rooney <colin.rooney at gmail.com>

>
> Kevin Brennan wrote:
> > We made some preliminary tests using vodafone's USB dongle and VoIP was
> > perfect.
> > USB dongle was connected to a router which accepts USB card which was to
> > a Thompson Speedtouch 716 acting as an ATA.
> > The far end voip device was a grandstream GXP2000 connected to a BT DSL
> > line, codec was G729 - VoIP was peer to peer meaning we did not bring
> > RTP stream onto our network.
> >
> > As I mention these were very preliminary, we only tested VoIP to VoIP
> > calls (and to be honest I was very surprised at quality) we will be
> > doing some more rigorous testing to see if we can consistent results.
> >
> > VoIP phones have built in echo cancellation (as do mobile phones) and
> > calls to PSTN are likely to be very echo sensitive unless VoIP/PSTN
> > gateways use aggressive hardware echo cancellation (which costs).  You
> > tend to get echo problems (to analogue phones) when ping  times go over
> > 50ms, in the TDM world national calls don't  need echo cancellation as
> > the round trip time would be sub 20ms, international destinations
> > normally have echo cancellation as a longer round trip time is expected.
> > It's different in the IP world where switches introduce delay and local
> > call latency is dependent your hops to the ITSP you are using. My point
> > here is that if the VoIP network is prepared for high latency then echo
> > should not really be an issue, and the only symptom of the large round
> > trip time is some delay in speech.
> >
> > Packet loss and jitter are another thing, for the moment you will
> > probably find hot-spots which can support VoIP well, but coverage will
> > be limited. It's early days for VoIP over mobile broadband and I would
> > expect we will see big improvements as demand heightens and networks
> > improve with HSUPA, HSOPA etc..
> >
> > Anyway, I think it's a milestone when you can currently make a VoIP call
> > over vodafone and quality is crystal clear with a package that only
> > costs 25/month -even if it's limited in coverage. I think everyone
> > (except the mobile operators) would welcome days when you could have
> > free calls on your mobile with no roaming costs (yes, you can pick up a
> > SIM in each country and keep the phone number) and keep your home phone
> > number.
> >
> > /KB
> >
> >
> > Michael Watterson wrote:
> >> Alan Ryan wrote:
> >>> 2009/3/5 Alan Ryan <alan at codecrunchers.ie>
> >>>
> >>>
> >>>> Hi Joerg,
> >>>>
> >>>>
> >>>> The e270 is up and running, pretty reliable.  Used a softphone
> >>>> today, but
> >>>> the quality was pretty bad alright.  I could hear them fine, but the
> >>>> other
> >>>> side said that there was a delay and terrible echo.  Is it the e270
> >>>> or the
> >>>> o2 connection that you think the problem might lie with?
> >>>>
> >>>> Alan
> >>>>
> >> The problem is Mobile Internet, not specifically O2 or the Modem.
> >>
> >> It has 100ms to 2000ms latency, typically 150ms
> >> High Jitter
> >> speed varies from 0.050Mbps to  5Mbps +
> >> Packet loss can be high or OK.
> >>
> >> It's inherently unsuitable for VOIP. If more than about 10 people are
> >> using your sector it's likely to be poor.
> >> It's possible to get more consistent VOIP on 40Kbps dialup!
> >
>
> As someone who is condemned to mobile broadband for use at home, I can
> agree that, from experience, voip on mobile is possible though not
> reliable.  Now it might work great and in an hours time you cannot stay
> connect for longer than 20 secs.  But it certainly can work and for long
> periods with no issues.
>
> Now I haven't read the terms and conditions for a while but I can
> remember when I began using mobile 3g (with vodafone initially), the
> terms and conditions of that contract explicitly forbade the use of
> VoIP. I guess the mobile companies did not want to lose revenue from
> potential mobile calls!?  Orperhaps the traffic from voip is to heavy?
> I don't know, but the point I wanted to make was that while it may work,
> if you plan to rely on it for your business then it may be prudent to
> check your terms & conditions of use to ensure it is allowable.  As I
> said it's been a while since I read these myself (I'm with o2 now) but
> it was definitely not allowed in the early days of mobile 3g.
>
> Colin
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