AT&T Grants Denies Us Mobile VoIP Freedom

Tom Keating : VoIP & Gadgets Blog
Tom Keating
| VoIP & Gadgets blog - Latest news in VoIP & gadgets, wireless, mobile phones, reviews, & opinions

AT&T Grants Denies Us Mobile VoIP Freedom

The big news last week was how AT&T grants denies us mobile VoIP freedom. Just last week I wrote how AT&T had "granted" us mobile VoIP freedom by finally allowing SIP port 5060 on their 3G data network. I was able to use siphon, a SIP-based application on my jailbroken iPhone to register with TMC's IP-PBX and make/receive phone calls.

Well apparently, AT&T must read my blog or something, because once again SIP port 5060 is blocked. I tried siphon on my iPhone this morning and now it won't register. I tested port 5060 and it is indeed blocked. Alas, so no more SIP calls using siphon. The AT&T Overlord giveth, and the AT&T Overlord taketh away.

Hey FCC, can you give AT&T a little smackdown for me please? Just last week AT&T announced it was allowing VoIP over 3G, so why the inconsistency? Is it because siphon is a jailbroken app and not an "official" iTunes app?  I doubt it. I doubt AT&T is able to detect what iPhone application is making an outbound connection. That would be a form of spyware if AT&T knew exactly which iPhone applications you were using. So seems to me that AT&T is still blocking VoIP calling over their 3G data connection. AT&T is talking a big game about being "open", but they aren't backing it up. I'm sure they'll blame it on some network glitch or something. AT&T could be dragging their feet on allowing VoIP over their 3G network hoping the mere "huge" announcement of support for VoIP over 3G will get the FCC off their backs. It's time for the FCC to stop AT&T's stalling tactics. I want my mobile VoIP freedom and I want it now!

Related Articles to 'AT&T Grants Denies Us Mobile VoIP Freedom'
Feedback for AT&T Grants Denies Us Mobile VoIP Freedom


Are you sure this is not gizmo5 specific problem and not ATT blocking anything? Siphon works fine with other voip clients eg, actionvoip.

If AT&T has changed the decision then It will be big disappointment for me. I need to call abroad too often for the business reasons. I'll have to go for spend some money behind it.

I have to agree with jeze earlier, are you sure it's not a problem outside AT&T's network? I, too, am using an Asterisk PBX and am able to register with a mobile SIP client. Dialing out and receiving calls both work as expected.

this is too bad. But if you think about, AT&T would lose alot of money if they allowed it. All providers have a hidden Monthly minute plan that is about 300 minutes [per month and is very cheap. the only way to get this is to call and explain to them why you dont need the original plan because its too many minutes, and so if VOIP was allowed alot of people could ask for that and use VOIP for all there minutes while paying very little.

Makes sense, but still would love to see this happen.


With all the confusion in the VOIP over mobile arena, there is a much less costly option which is just coming to market, Cellular Over Internet Protocol where you get local network dial tone on any cell phone.

This is the better solution on all fronts, first, any phone can be used, not just GSM smart phones like all the others, plus no additional data plan charges, never mind current TOS denies use of data network for voice, as in VOIP applications, so it makes you wonder what is going on?

COIP is not a band width hog like VOIP over data is, so another plus given peak bandwidth is upon us, just look at how AT&T couldn't support iPhone 3GS applications, and this is a problem with all carriers now, or in the near future, so I vote for as the best solution, especially for international calls worldwide, something not possible with VOIP over mobile.

Add in WiFi, WiMax and you have a solution for everyone, just makes sense to me.

That's pretty disappointing, and it is true, AT&T always mess up with their VoIP servers. I used to had AT&T, but i fed-up with their 24X7 busy server and congestion. I tried several other services too, but i found one from convincing. I fixed this a month before, I am happy for not facing congestion since last one month.

Hello Tom,

A query here - we are using the service of a bulk-SMS provider to send some validation SMSes to users of our web-application.

We are infact using TringMe's application for this purpose.

While we are able to deliver SMSes all networks across the world, only AT&T subscribers are not able to receive these SMSes. While subscribers of other operators like T-Mobile can also receive these SMSes.

What could be the possible reason for this? Considering TringMe can deliver SMSes to all regions and other operators in the US except AT&T?

What could be a possible resolution for this?

Your views will be greatly appreciated as it could help us solve a major roadblock to our service.


Featured Events