Help Configuring APN on ATT network

[sunny11]

I bought a SGS2 Brazil/Argentina version (Baseband ver. I9100UHKI1) and trying to use it on ATT 3G network. How do I configure the APN?
Do I use ATT WAP, or ATT Phone option?
the 850Mhz band is enabled, I checked it already.

thanks.

 

[3waygeek]

Here are the two APNs I've used successfully:

Name: Cingular
APN: wap.cingular
MMSC: http://mmsc.cingular.com
MMS proxy: wireless.cingular.com
MMS port: 80
MCC: 310
MNC: 410
Auth type: none
APN type: Internet+MMS
All other fields blank

Name: AT&T HSPA+
APN: phone
MCC: 310
MNC: 410
APN type: internet
All other fields blank

The HSPA+ APN seems to require a 4G data plan; before I upgraded to a 4G plan, I could connect to it only intermittently. Once I upgraded to 4G, I can connect to it without problems, and have gotten up to 9.5 Mbps.

 

[sunny11]

I called ATT to change my data plan from 3G to 4G to use the second option you have suggested. The tech support asked for the IMEI number and gave it to him, but could not complete the transfer because it is not an ATT IMEI number.

How did you upgrade to 4G data plan?
Thanks.

 

[3waygeek]

I just went down to my local AT&T store and asked them to change me from the 3G smartphone personal plan (soc code DPPB) to the 4G plan (soc code HSDPPB). They popped the phone open to make sure I had a current SIM and read the IMEI off the label. They didn't say anything about it being a non-AT&T phone (it's an international SGS2 I bought back in May). The entire process took less than 5 minutes.