
That's like saying that ISDN lines and SIP are the same thing because they both use G.711 ulaw with common channel signalling, and it's really up to the phone companies they could be using SIP over ISDN instead. The difference is that the digital data you speak of is using codecs designed for high loss and corruption, has a delay certain model (unlike packet switched data) and doesn't have overhead (like IP). -Paul On 09/14/2011 11:22 AM, Carlos Alvarez wrote:
You seem to be suggesting that there is a technical reason the carriers don't do this. There is not. Carriers prioritize voice channels, which really are just data also, though not using SIP. They *could* choose to prioritize data, or do the usual QoS for the data so VoIP has good quality, just like any other IP connection. They won't, because it's a huge threat to their business model.
On Tue, Sep 13, 2011 at 9:07 PM, Paul Timmins <paul at timmins.net <mailto:paul at timmins.net>> wrote:
My android phones do SIP user interface integration over HSDPA and EVDO respectively, and frankly, the voice quality isn't that great. Much worse than the underlying GSM or CDMA signal bar for signal bar.
There's a reason the carriers aren't doing this yet. -Paul
On Sep 13, 2011, at 11:32 PM, Scott Berkman wrote:
You might want to see if LightSquared has anything for you, they dub themselves the ?only wholesale-only mobile carrier?, but I?m not sure what they can offer today. http://www.lightsquared.com/ Also, aren?t some of the newer cellular technologies (UMTS or EVDO) inherently built on SIP for the voice portion of the network? That?s not an answer to your problem, but? One other thing you might want to look into is an OS that allows the default phone app to use SIP over the data connection natively (as opposed to using a separate soft phone application that might not integrate as well to the UI). I believe this was preset in versions of WM6, but that?s somewhat old now and I have no idea if it?s built into any other platforms. http://voipguides.blogspot.com/2008/05/voip-sip-client-for-windows-mobile-6.... -Scott *From:*voiceops-bounces at voiceops.org <mailto:voiceops-bounces at voiceops.org> [mailto:voiceops-bounces at voiceops.org <mailto:voiceops-bounces at voiceops.org>]*On Behalf Of*Carlos Alvarez *Sent:*Tuesday, September 13, 2011 3:44 PM *To:*VoiceOps at voiceops.org <mailto:VoiceOps at voiceops.org> *Subject:*Re: [VoiceOps] Cell Phone to SIP provider It is my understanding that: a. The original post asked about sending the calls to the end point (cell phone) as SIP, not cellular voice. b. Sprint's MIS (Mobile Integration Service) merely allows a company or service provider to connect to them directly over TDM or SIP and do seamless integration of the cell and other phones, but the call is still cellular voice to the handset. I am facing a competitive sale right now to a municipality where there is only one other carrier who can compete with us, and only on that one feature.
On Tue, Sep 13, 2011 at 12:33 PM, Matthew S. Crocker <matthew at corp.crocker.com <mailto:matthew at corp.crocker.com>> wrote:
Sprint does this. The cell phones register to the cell tower as cell phones. The cell tower converts to SIP and registers with the call agent. Broadsoft mentioned something about this at the last connections conference. You would get a private IP connection into Sprint to carry the voice traffic. This would be perfect for me if Sprint had a decent cell network in my area. Does anyone know if AT&T or Verizon (LTE) do it as well?
http://newsroom.sprint.com/article_display.cfm?article_id=1628
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*From:*"Oren Yehezkely" <orenyny at gmail.com <mailto:orenyny at gmail.com>> *To:*"VoiceOps at voiceops.org <mailto:VoiceOps at voiceops.org>" <voiceops at voiceops.org <mailto:voiceops at voiceops.org>> *Sent:*Tuesday, September 13, 2011 1:00:02 PM *Subject:*[VoiceOps] Cell Phone to SIP provider
Hello,
I am looking for a cell phone company that is capable of providing SIP service instead of sending the calls over the cellular network.
If anybody here is capable of providing such a service or can recommend a vendor that can do that, please let me know.
Thanks,
Oren
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-- Carlos Alvarez TelEvolve 602-889-3003 <tel:602-889-3003> _______________________________________________ VoiceOps mailing list VoiceOps at voiceops.org <mailto:VoiceOps at voiceops.org> https://puck.nether.net/mailman/listinfo/voiceops
-- Carlos Alvarez TelEvolve 602-889-3003
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