How well does the iphone 4S work in Vietnam?

Good morning fellas,

I broke my little iphone 3.  Now, I am thinking about getting an iphone 4S sent to me from the US. 

But, I have had my share of problems using the 3 here.  I wonder how the 4S is going to fare?  Can any of you share with me your experiences?  What is that tweaking with the sim thing ("ghep sim")?  How well does that work, as compared to "unlocking" it?  What about taking the phone back to the US, will it work there still?  Most of the people I know use the iphone 4 from Singapore or Hong Kong.  According to them, the US ones are a bit different.  As in what?  Will Siri work here?

Thanks in advance.  And Chuc Mung Nam Moi to all.


According to the technical press, a new iThingy version 5 will be released this summer.

This new version will have the capability of using both GSM or CDMA networks selected from the menu.

The differences between US systems (along with Canada) is FREQUENCY. The USA always has different standards - Canada is forced to go along with them as it is next door - be they frequency assignments or modulation characteristics.

You might of heard of Tri-band cell phone, or Quad. These refer to the number of frequency bands a cell can handle. Low band is 850 MHz and High band is 1900.

The World and it's dog (except North America) use 900 and 1800 MHz.

Canada actually needs a 6-band cell to accommodate all the newly introduced frequencies there.

The good news is, you don't have to worry about any of this with Android, iOS and other smartphones as they look after everything.

WHAT YOU DO have to be concerned about that even if you buy an unlocked iThingy from Apple, the American cell networks will lock them up, defeating the unlock feature. UNLESS you jail break a iOS system you are effectively screwed, once locked.

Most other networks in the world honour an unlocked phone.

In VietNam the best coverage is provided by Vinaphone and it's wholly owned subsidiary Mobiphone, they both use the same base stations.

For younger people, Mobiphone provides some cute features apart from being cheaper than Vinaphone.

Both Vinaphone and Mobiphone are authorised iThingy distributors in VietNam. Both have main offices on Nguyen Du (at the intersection with Hai Ba Trung) and have competent technicians in attendance.

The 4S was released here within a month of it's release in North America.

There are repair stores both in HCMC and Ha Noi who might be able to help you until V5 emerges.

IF YOU WANT Siri, think carefully before spending your money, Siri is still in Beta.

Siri, the voice response software, has problems - big problems. It gobbles battery, it gobbles band width.

Some people say it's like conversing with a person in outer space, somewhere around Mars, because of all the main frame/server problems as well as the sluggish data connections.

Ask Google: >> problems with siri <<

Remember, the Siri software is useless without a decent connection ... which makes your V3 look pretty good, especially considering Lemon 4 never did work properly.

As I said, Version 5 is coming, so why not get your V3 patched up - there are several repair shops around Ton That Tung Street and the intersection with Nguyen Thi Minh Khai Street in Quan 1, Ho Chi Minh City.


Thanks for the exlainations and tips.  I broke the old phone really good; there is no way to repair it now.  But, holding out for the 5 was exactly what I was doing.  I was not very fond of the antenna problems.

But, unlocking, isn't that tweaking the solfware so that the phone will read SIMs from a different region?  If I were to buy a phone here, will I have to do the same when I bring it to the States?


Jailbreaking is getting rid of Jobs petty software control techniques whereas unlocking is a legal way of providing access to all networks BUT the software control remains.

Remember, those damn North American networks re-lock an unlocked cell (they tell you in the user agreement. You can only get the unlocked versions from Apple stores, so if you have a friend buy one for you, be very careful! Don't let him sign-in!

The unlock feature is through the network, not by the network, Apple issues the commands from it's facility. Other cells unlock through keyboard control.

The V5 has the dual modulation system - GSM/CZDMA - which, with unlocking will give you world wide access.

Don't buy anything for Siri, apart from being in Beta, the excessive data demands load the systems, which delays response, and runs your data plan usage up.

Personally I use an Android, so I can load anything on it.

If your present plan times out (as in unused) Mobiphone has cheaper rates than Vinaphone. I travel VN widely and there are very few areas not covered by these networks - the CGST uses the Vina network instead of two two-way radio - a few places in Son La Province and Lai Chau Province up in the mountains.

Vina and Mobi even have coverage in the Spratly Islands. They also have service in Phu Quy Island (120 kilometres off Phan Thiet) except between 24.00H and 06.00H when the island switches the power off!

This is our 'cell' in our DakLak
workshop - any system or frequency!
But not exactly portable, either.


Happy New Year my old man.

As Jaitch said, if you buy a OFF-CONTRACT, AT&T, Quadband iphone 4S, the phone is already unlocked. It is important to note:
   - Buy AT&T since they use the GSM system which is compatible with much of the world. Verizon uses CMDA system which, first of all, does not use a SIM card, let alone being compatible with the rest of the world.
   - Buy a Quad band since the US GSM system uses a different frequency band than the rest of the world, so buying a quad band phone would make it compatible to more countries. However, I think a tri-band is also usable in Vietnam.
   - Off contract since it is not locked to AT&T so you can use other companies' SIM card. Having said so, the Vietnamese technicians are quite good so they can unlock the phone for you for a few bucks.

Once you get the phone to Vietnam, you get to cut the Vietnamese SIM card (in half) to fit the so-called microSIM format of the iphone. Again, hire a technician if you are not comfortable.

Some told me also go to Settings menu to change the following for better compatibility:

Settings > General > Network > Cellular Data Network — Under Cellular Data: APN – m-wap, Username – mms, Password – mms

>What about taking the phone back to the US, will it work there still?

Yes, even the one you manually unlock in Vietnam. Worst thing: you can already reset it to mfg condition. A technician can do it for you easily.

>Will Siri work here?
Yes. Best when you have WiFi coverage: cheaper and fast. Not sure it is worth the price alone.

Hi Anatta,

How was Tet my funny friend?

So, buy the phone straight from AT&T (no contract) or at the Apple store and that should work fine here?  Do they still sell it that way?  I remember there were time that the contract was a must.

Thanks again fellas.


It used to be sold with a plan only, then both due to competition and customer complaints, they started selling unlocked phone a few years ago.
Go to apple store and choose

"Or get iPhone unlocked and contract-free" at the bottom of the screen instead of choosing one of the three phone operators on the top.

Tet was quiet where I went. Took a trip to Europe with the family. London was crowded. Good New Year sale, but only for winter clothing: nothing for this poor fellow.


Thanks for the tips.  I think that is what I am going to do, right after I check with Mobiphone.

Oooh, England, hey?  That must have been good.


If you are living in VN wouldn't you be better off getting it here? Both Vina and Mobi are authorised iThing dealers and, by VN law, they have to sell them unlocked.

The V5 is an 'all band' unit - whether a frequency is used now or in the future. Frequency assignments are set by the SIMs.

SIM card cutters are on sale in the area of Q1 - TP HCM I mentioned above (Vina and Mobi at Nguyen Du offices have them for you to use). Apple has applied for a SIM-less (e-SIM) GMS registration; CDMA already uses SIM-less (or e-SIMs).


That is what I was thinking about.  I am going to check with Mobiphone tomorrow, since they have been my carrier from day one.  Are you sure they have iphones?  I know that Vina and Viettel have them.

Wild_1 :

That is what I was thinking about.  I am going to check with Mobiphone tomorrow, since they have been my carrier from day one.  Are you sure they have iphones?  I know that Vina and Viettel have them.

Mobi is a subsidiary of Vina (common network, too).

Last year Vina were telling their customers to get a iThingy from Mobi, when Vina ran out of stock. (The offices on Nguyen Du, Q1, TP HCM - call them, the call is free!)


iPhone 4S unlocked by Vietnamese student
Last week an on-line forum has been buzzing over the fact that an untethered iPhone 4S has been successfully unlocked by a young Vietnamese man without physically changing the phone!

A year ago a Gevey SIM could be used to unlock an iPhone 4, but now iPhones are secured by iOS5. In addition, jailbreaking, or running the iOS operating system through the use of custom kernels, has not been comp[leted for 4S.

This has slowed the 4S iPhone market, since almost no traders dare to import the product for sale, although the potential profit is very lucrative.

However, last week Le Minh Tuan, a Vietnamese university student in architect in Saint Petersburg, Russia, posted a simple method of unlocking an untethered iPhone 4S on Tinh Te, a science and technology forum at < > under the username Fullove.

To unlock an untethered iPhone 4S, users need a USB SIM card reader, a magic SIM (6 in 1), a local network SIM card, and a SIM produced by the Internet service provider that locks the phone, such as AT&T, T-Mobile, Telus, Bell or SFR, Tuan said.

He showed that the unlocking is carried out through four steps on his AT&T iPhone 4s:

Step 1: Insert the AT&T SIM into the USB SIM card reader using Magicsim v255 to back up ICCID, IMSI, and SMSC of the AT&T SIM.

Step 2: Then insert the local SIM into the USB SIM reader. Tuan used a Beeline SIM with Magicsim_v255 to get the parameters of the SIM including ICCID, IMSI, SMSC and KI – the most important tool to clone a SIM. Note: copy a new style SIM that has not been used for calling. Data changes after use!

Step 3: Plug a magic SIM (6 in 1) into the USB SIM reader and record at location No. 1 the above ICCID, IMSI, SMSC and KI of the AT&T SIM and record at location No. 2 the the Beeline SIM’s ICCID, IMSI, SMSC and KI that have been taken from the USB SIM card reader.

Step 4: Plug the magic SIM (6 in 1) into the iPhone and carry out the process: settings -> phone -> SIM Applications -> Switch Number where the user selects the Beeline SIM -> main screen. The iphone will activate its search carrier and identify the Beeline network. The subsequent manipulations are illustrated in a video clip attached to Tuan’s posting on the forum’s website.


Tuan’s posting has stirred up the forum with tens of thousands of hits and comments, with many by iPhone 4S users agree that this is a possible way to unlock an iPhone 4S in VietNam to use it through the local Internet service providers.

However, The most difficult thing to do is to search for the KI using a local SIM, since SIMs of the latest versions have been secured by COMP-2 instead of KI, as in several years ago. Therefore, the search for KI using a USB SIM card reader will be very hard, even impossible.

A member of Tinhte confirmed that Tuan’s unlocking method helped that member unlock an iPhone 4S using a SIM card from 2005.

However, the fact that an iPhone 4S can be unlocked only with SIMs of older versions made it hard for most users to unlock their phones. Minh Hoang, another member of the forum, said, “How can I have a SIM card produced in 2005 or older search for KI?”

On the other hand, Le Hoang Tung, who is in charge of technical issues at VinaPhone, said KI is a system code that is not allowed to be disclosed for confidentiality purposes.

Tran Thinh, from the technical department of military-run Viettel group said, said, “KI is a password that is not provided to anyone. Viettel SIMs are now secured by COMP128V2 with high confidential ability, and if users try to search for KI, their SIM cards may be ruined.”

Tien Duong, who is in charge of iPhone unlocking services at a phone company in Hanoi, said, “The method of unlocking introduced on Tinhte is right, but it is not highly feasible, since Internet service providers in Vietnam have strengthened security ability for their SIM cards following the many cases of SIM hacking that have happened.

The easiest answer is to buy an Android - unlocked and open!

Alright gang,

I had just visited Mobiphone, and they don't carry the ithingy.  They only have Blackberries and Motorollas.

I will pass by Nguyen Du offices later and get the low down.

They had it since way back < … one-rivals >.

Should post or PM by 19.30H, I have to pick up junior from night skool today.

Hi Howie,

Hope this help. Not sure if this is old news.

By the way, I am arranging to meet Bryan in Can Tho mid Feb. Wondering if we can catch up for a drink! You can PM me as well. Thanks. … this-week/

Vietnamese carriers to launch iPhone 4S this week

by Michael Grothaus
Dec 14th 2011 at 11:00PM

Back in October, Viet Nam Business News reported that the iPhone 4S would go on sale in the country by the end of the year. Now Thanh Nien News is confirming that Apple's latest smartphone will go on sale in Vietnam by the end of this week. Vietnamese carriers VinaPhone and Viettel have both confirmed that they will begin selling the iPhone 4S this Friday.

As is the case with the iPhone in most foreign countries, users can expect to pay much higher prices than in the US. VinaPhone plans to sell the 16 GB iPhone 4S for VND15.6 million (about US$740) while Viettel will sell the same device for VND16.4 million (about $780) on contract.

Thanh Nien News also reports that Vietnamese iPhone users who want the device off contract will have to pay an additional VND600,000 to unlock the phone. However, it's not clear if that sum is correct, since it's roughly the equivalent of only US$28.

Hi Michael,

It will be a pleasure to meet you.  Bryan, his wife and I, have been getting together quite a bit.  He is a very cool young man.  Thanks for the run down on this ithingy of mine though. 

I have never bought any gadget here, ever.  But, I have brought my old phone here, had it unlocked by Vietnamese technocrats; but it did not work the way it was supposed to.  I couldn't log onto this site from my phone.  Anyhow, there were limits to their abilities.  That was something that I didn't really want.  Therefore, this time around, I want to get things right.  I want my phone to work the way it should...

Anyhow, thanks to all of your tips.  I will find out where Vinaphone is in Can Tho, pay them a visit before I decide.  A 16g 4S, in the US, cost about $700 USDs.  But, like I had mentioned before, it is the peace of mind that I am really after.


As said elsewhere, the 4S is imminent. Mobiphone have completed their sales quota of the Lemon 4 and is waiting to sign on for the 4S. They have zero stock.

An unlocked 4S, without contract, from Vinaphone, without SIM costs as follows:
iPhone with 16 Gigs of memory: VND16,399,000
iPhone with 32 Gigs of memory: VND18,799,000
iPhone with 64 Gigs of memory: VND21,299,000

The number for the Vina Nguyen Du office is 094-976-3468 and she will be happy to give you status. Give her your number and she will call you.

I couldn't understand how to get on the wait list.

How U.S. Carriers Fool You Into Thinking Your iPhone 4S Is Unlocked

The dual-mode iPhone 4S is a billed as a universal phone, but only if purchased from Apple.

If you ask most cell phone users what they understand the term “unlocked phone” to mean, they will likely tell you that it is exactly what it says: that you can use the phone on any cell carrier anywhere. Well, this is not exactly true with the iPhone 4S.

The iPhone 4S is the first device produced by Apple that is a dual-mode phone. This means the iPhone can theoretically be used on any CDMA or GSM network, in any country. In the United States CDMA is the protocol for Verizon and Sprint, while GSM is used by AT&T and T-Mobile. Internationally there are about 40 CDMA countries and more than 220 GSM venues. International phones have to accommodate different protocols and frequency bands for voice and data services, depending upon carrier and location. The 4S meets this requirement almost everywhere.

Apple did a very smart thing when they designed the 4S. Rather than having to produce a GSM version and a CDMA version of their popular phone as they had done in the past, they combined the two protocols in one chip set, which should save the company potentially billions of dollars, and make distribution and logistics infinitely simpler. It also means that the consumer only needs one phone to travel anywhere in the world, absent a lack of roaming agreements between their home carrier and the system they are trying to use while out of the country.

Last month I purchased an iPhone 4S from Best Buy Mobile for use on my Verizon account. I paid full retail so there would be no restrictions from Verizon with regard to unlocking the handset. My intent was to run tests in Europe and the U.S. to determine if the phone would perform as well as competitive CDMA-GSM phones that I have used (Android and Blackberry). Initially, my focus was on how well Apple handled the different issues required for roaming on foreign carriers and whether the Apple iOS 5 offered the same level of connectivity and data options that Android and Blackberry provide.

Verizon registered the phone on both their CDMA network and the pre-installed Verizon-Vodafone GSM SIM card so I could roam internationally as a Verizon customer. I contacted technical support before leaving for Europe to have the phone unlocked. Verizon stated that I would have to meet certain conditions in order to unlock the phone.

These were: I had to be a Verizon Wireless customer. The device had to be active on a Verizon line (unless I was upgrading from an older global phone that had a 3G unlocked SIM for at least two months). My line of service had to be active for at least 60 days and the account had to be in “good standing” for the past 60 days (meaning a current balance and no service suspensions in the past 60 days). Only one unlock per line every 10 months.

What this rigamarole means is that a non-Verizon customer cannot unlock a phone they purchased from someone other than Verizon, nor can a customer that has only subscribed to the service for less than sixty days, even if the phone number was ported from another carrier. If you upgraded a handset which has been active for at least two months then the phone can be unlocked.

Verizon Rules regarding the use of unlocked phones

While Verizon does not specifically address just exactly what an unlocked phone really means, they do require a customer to agree to a number of conditions. It is somewhat perplexing that this particular carrier seems to think they can regulate the use of your phone on foreign carriers that are not allied with Verizon, especially where prepaid SIM cards are used. I especially find this condition, below, rather perplexing because it indicates that Verizon maintains control over your phone and usage even if you are not using their network.

    You agree that, to the extent applicable when using Other SIM Cards, Your use of the Global Phone remains subject to Your Verizon Wireless Customer Agreement, Calling Plan and Global Phone terms and conditions, including without limitation, the requirement to abide by all applicable foreign laws when using the Global Phone outside of the United States.

    If you try to insert a SIM card from a U.S. GSM carrier into an iPhone that was purchased from AT&T, Sprint, or Verizon, this or a similar message will be displayed and the use of the SIM is blocked.

Unlocking your Iphone 4S

Among the three major carriers operating in the U.S., only one, AT&T, will not unlock any iPhone. Because I purchased a Verizon-designated handset, the following information relates to those customers that purchase Verizon iPhones, but the technology and result is the same for any carrier.

When I called Verizon tech support to unlock my phone prior to leaving the U.S., I was told that I had to have a foreign SIM card installed in order to complete the process and that the phone would have to log in to the Verizon network on WiFi. The reason for this procedure is that the phone must validate the foreign SIM.

Unlike the unlocking of a Blackberry, Motorola, or other global devices, the iPhone accomplishes the task somewhat differently. Usually the subscriber sends the electronic serial number of the device to the carrier and in return an unlock code is provided to the customer. That code is then entered into the phone and it will work on any carrier, anywhere. I did not have a foreign micro-SIM card (only standard sized ones for the carriers I routinely use when overseas) so I had to wait until I was abroad.

So I stopped in at an Apple store in London. We logged into a WiFi network, installed a micro-SIM card from a carrier in England, and within about thirty seconds, the phone was unlocked because Verizon had already unlocked the phone at their end before I left the U.S. For the rest of my travels overseas, it worked flawlessly and provided essentially the same options that are available on any other dual-mode or GSM-only device. So if you want one phone for communications anywhere on the planet, the iPhone works quite well for both voice and data services. And once it is unlocked, you can use foreign SIM cards for local service at reduced rates.

However, this is only the beginning of the story, and the part which is most relevant to U.S. consumers who want to buy and use their iPhone on Verizon, AT&T or Sprint while in the United States as well as when they are overseas.

If you are intending on purchasing a new iPhone 4S, read on, because these three carriers are neglecting to tell their customers critical information that could influence the decision as to where to purchase your new phone. When a carrier tells a customer they can unlock their phone, the understanding is that the handset can be used on any system. This is not true, and when I spoke with employees at all three carriers and Apple, everyone essentially agreed that customers should be told the truth about unlocked iPhones.

Four different iPhone 4S versions

When I returned to the U.S., I wanted to confirm that my Verizon iPhone could be ported to another carrier, whether CDMA or GSM. This was the intent of Apple when they designed the 4S: every phone is the same and will work on virtually any carrier in the world.

So, I contacted a regional GSM carrier in the Midwest that has roaming agreements with AT&T and T-Mobile. The carrier was kind enough to provide a micro-SIM card for testing in my iPhone. What I found may infuriate customers who have purchased expensive iPhones from one of the three carriers in the U.S. but at some point decide to switch to another provider because of poor coverage, customer service, or pricing. There is a high churn rate in the cellular industry, which is one reason the carriers want to do everything possible to lock their customers into staying with them. It is the same reason that makes your decision as to where to purchase an iPhone even more critical.

Sitting in South Dakota, I replaced my Verizon SIM with the Longlines Wireless chip. The phone indicated that the SIM was not recognized by the phone and required its removal and device reboot. I contacted Verizon global support to confirm my suspicions. They advised that indeed their phones were locked as against any other carrier in the United States, and that the term “unlock” only applied to overseas carriers.

I next inserted my UK SIM card into the phone, and it logged into AT&T without issue, which confirmed what Verizon told me. I then interviewed managers at three different Apple corporate stores to confirm issues with regard to unlocking. What consumers need to understand is that there are actually four different versions of the iPhone 4S: Verizon, Sprint, AT&T, and Apple. Only the Apple phone, available from their stores or on-line, is fully unlocked and can be used on any carrier outside the United States. The other phones are permanently locked and cannot ever be used on another carrier in the U.S. Even if you spend $800 for an unlocked phone as I did and dedicate it to a single U.S. carrier, you are locked into that carrier forever if you want to keep using the iPhone. Neither Apple or the other carriers will fully unlock your carrier phone.

Apple declined to return phone calls and emails to discuss this matter. However, the high level technical support supervisor that I spoke with at length indicated that she personally thought that customers should be warned about the different versions of the phones and ramifications of buying a phone directly from a carrier rather than Apple. A senior spokesperson for Verizon told me that all Verizon phones are locked to their network and she did not quite understand the problem. I am willing to bet that Verizon customers would precisely understand this issue, even if she did not.

So if you paid retail for your iPhone 4S and purchased it from Verizon, Sprint, AT&T or Best Buy, you will never be able to use that phone with a different carrier. In my view, this is a scam by these companies. I think the cellular providers should tell their customers up front that locked phones really mean that you are locked into the carrier forever. While all of these phones are iPhone 4S with the identical hardware, the difference is that if you purchase your phone directly from Apple, it is truly a universal device and will allow you to change carriers without the penalty of making the phone worthless.

I would urge the Carriers, FCC, or Courts to enforce the following rules to protect cellular customers in the United States.

    >> consumers buying new cell phones must be informed of the existence of any SIM LOCK (also known as a network lock) on their phone before sale;

    >> wireless phone companies must unlock handsets upon request, without fee, when a consumer purchases a new phone outright (unsubsidized) without a contract;

    >> wireless phone companies must unlock handsets upon request, without fee, when a consumer comes to the end of their contract, or at any time thereafter.

    >> Carriers must fully unlock their phones (as does Apple with the iPhone 4S) and not partially unlock the phone to block access to other carriers and deny consumers the right to choose any provider anywhere.

Apple has taken the lead in producing a dual-mode phone that is unlocked for all carriers and is technically capable of being used on any GSM or CDMA system. However, after obtaining a fully unlocked version of the 4S, I found that Verizon and Sprint refused to register it. AT&T, T-Mobile and any other GSM carrier in the U.S. will allow the fully unlocked version to be used. Only the CDMA carriers are blocking access.

The real question is when Android will follow suit with a dual-mode Nexus? Either way, fully unlocked phones give consumers a choice of carrier. The high cost of smartphones should not be the criteria by which customers determine whether they can change their service provider.

In summation, buying a 4S and using it ona U,S, carrier means you are scammed.

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