[asterisk-users] OT: Samsung Sprint CDMAoIP

[Eric Chamberlain]

> -----Original Message-----
> From: asterisk-users-bounces at lists.digium.com [mailto:asterisk-users-
> bounces at lists.digium.com] On Behalf Of C F
> Sent: Friday, September 21, 2007 7:34 AM
> To: Asterisk Users Mailing List - Non-Commercial Discussion
> Subject: Re: [asterisk-users] OT: Samsung Sprint CDMAoIP
> 
> On 9/21/07, Alexander Lopez <Alex.Lopez at opsys.com> wrote:
> >
> >
> > Snip headers
> > > On 9/20/07, Jason Parker <jparker at digium.com> wrote:
> > > > C F wrote:
> > > > > AFAIK, the calls are free when you use it thru that device. Sprint
> > > > > however charges $15 a month per phone or $30 for family plan.
> > While I
> > > > > agree that sprint should pay me for this, it's not as bad.
> > T-mobile on
> > > > > the other hand, does the same thing with wifi enabled phones, it
> > > > > doesn't cost extra, and is completely free.
> > > > >
> > > >
> > > > If you're referring to T-Mobile's "HotSpot at Home" service, it's
> > actually
> > > $20
> > > > per month, per line on the account (unless it's changed very
> > recently).
> > > >
> > >
> > > I don't know about that, could be you are right.
> > >
> > > > As far as how it works on T-Mobile, I recently had some questions
> > > answered by
> > > > them about that..  They use UMA over wifi, and it does automatic
> > > switching
> > > > between the wifi and the gsm towers (ie; your call stays up).
> > >
> > > The same goes for Sprint.
> > >
> > > >
> > > > Quote from the tech I talked to:
> > > > "HotSpot at Home does not use a VoIP protocol, as the voice data is
> > > > transferred from the Internet directly to our UMA Gateway and then
> > > > through our regular Mobile Switching Centers."
> > >
> > > I know it's a quote from the tech, but isn't it voice packets that
> > > travels over the Internet (a packet switched network) instead of over
> > > GSM (TDM switched network) which makes that statement incorrect? It
> > > doesn't matter what the higher level protocol is, it's still VoIP.
> > >
> > Your right it is "STILL VoIP" by definition but its not...
> 
> Yes it is, not only in definition but in practice as well. See below.
> 
> >
> > From: http://www.newstep.com/our%20market/technologies.asp
> >
> >  Gateway-based Solutions
> > By placing special gateways at the edge of a GSM network, Unlicensed
> > Mobile Access (UMA) allows users with dual-mode handsets to access
> > mobile phone services via both cellular and Wi-Fi links. In cellular
> > mode, voice traffic travels over standard GSM radio waves. In Wi-Fi
> > mode, an IP tunnel carries GSM traffic across the enterprise network
> > and/or the Internet to a UMA gateway. The gateway looks like a base
> > station controller (BSC) to the cellular network, so when a handset
> > moves between cellular and Wi-Fi coverage, the network handles it as an
> > ordinary BSC-to-BSC handoff. MSC emulation-also known as IP VLR-is
> > similar to UMA, except that the gateway mimics a mobile switching center
> > (MSC) and a visitor location register (VLR) instead of a BSC.
> >
> > Intimately tied to cellular technology and dual-mode handsets,
> > gateway-based solutions provide access only to mobile network services
> > and can be deployed only by facilities-based mobile network operators.
> > Moreover, gateway-based solutions cannot leverage the full capabilities
> > of IP and VoIP because all voice traffic remains in TDM format. Service
> 
> When the above line is taken out of context (which is what I
> understood from your response) then it could be said that it suggests
> it's not VoIP. But really all the paper is saying is that to the
> network (GSM) it doesn't look like VoIP but like TDM, since it's in
> that format, and can therefore not take advantage of most VoIP
> features. But it's still VoIP.
> 

It's GSM tunneled over IP, some of the data traffic may or may not be voice traffic in the GSM traffic in the IP tunnel.  Calling it VoIP would be a stretch.  

--
Eric Chamberlain, CISSP
Chief Technical Officer
Voxilla - http://voxilla.com/