[AT&T Samsung Galaxy S II SGH-I777] locust43:
Hey all, hope this is the correct forum to post.

This is a Fix it guide I wrote for AT&T user's. These are the correct settings for your AT&T Samsung Galaxy S II

I hope this helps everyone who has been possibly experiencing slower speed's on AT&T Mobility.

1'st, make sure you are on the CORRECT data plan.

1. HSPA+ 4G 2GB plan OR for Unlimited Customer's

2. Smartphone Personal Data plan with 4G SOC code : HSDPPB

Then under your APN settings, I have found personally that WAP.CINGULAR is not the right APN. When your tethering you can tell what the correct gateway you should be connected to by visiting speedtest.net tethered to a PC and seeing when you run the test by your IP, it should show SERVICE PROVIDER and NOT AT&T GLOBAL NETWORK SERVICES.

Wap.Cingular connects you to the older gateway made for 7.2 phone's. I found in real world AT&T testing it caps/throttles you at around 7.5Mbit/s or slower.

FIX:

Under you Access Point Settings click on each APN you already have then in the menu, delete them.

Next create a new APN:

Menu Key, New APN.

Name : AT&T HSPA+

Important step: tap APN and enter exactly : phone

That's it! It's literally just "phone", not kidding. Leave everything else blank including Username and Password!

Scroll down to APN Type, Select Internet only

Hit the Menu Key, and hit SAVE

Your will return to APN settings, go to the APN you just created called AT&T HSPA+, tap the dot next to the APN and make sure it turns green!

Now for the MMS settings

Step 2 : MMS Settings

At the APN settings hit the menu key again and create a new APN, call it MMS

Under APN again just type : phone

go down to MMSC and fill the fields as follows

MMSC: http://mmsc.cingular.com

MMS Proxy: wireless.cingular.com

MMS Port: 80

MCC: 310

MNC: 410

APN type: MMS only

Now again hit the menu key and save. This will be your default MMS setting and you will not need to select it.

Once your back at the APN menu with the fields you just created, make sure AT&T HSPA+ still has a green got by it.

Now hit the home key, then turn your phone off and back on.

You should have full internet access if you have the correct data plan. While you may not experience faster data speed's in every area. This APN will allow you to have more consistent and through speed's, especially in an AT&T "4G" HSPA+ enhanced backhaul area.

Here show's the difference in the two APN's. The first SpeedTest is the Wap.cingular, the second is the one we just created.

Old APN:

New APN: Better ping and better speed, Notice Service Provider vs. AT&T Gobal

If you guys have any questions feel free to ask me in the forum or PM me.

I really hope this help all of you Galaxy S 2 users on AT&T!!

UPDATE 07/17/2011 - Possible slow data speed explanation theory..

Ok. So I think I may have found a reason why the SGSII is slower than phone's like the Infuse and has so many radio problems.

You guys remember with the Apple iFail 3G through the iPhone 4 on AT&T and other GSM providers, with the severe signal issues and dropped calls??

It was later tied to the Infineon modem in the handset powering the devices..

http://news.cnet.com/8301-13579_3-10015301-37.html

Well unfortunately, stupid Samsung put an Infineon baseband modem chipset in the Samsung Galaxy S II's.

To me I have the SAME issue's I was having with the iPhone 4.... Coincidence or not?? You decide. But the SGSII has the chip, it is HSPA+ capable but of course since Infineon makes it, it likely cant hit H+ speeds.

http://www.wired.com/gadgetlab/2011/03/silicon-art-samsung/