Carrier Bundle

Carrier Bundles provide a way to organize all customizations related to carriers in one place. These include voice mail numbers, MMS and APN settings etc.

For users on carriers other than the Apple's official partners, carrier bundles allow to configure important settings such as APN and enable features like MMS and tethering.

On the iPhone side, carrier bundles are stored in the following directories:

• /var/mobile/Library/Carrier Bundles/ - bundles downloaded via iTunes.
• /System/Library/Carrier Bundles/ - bundles provided with the firmware image.

If two bundles with the same name exist in both paths, the one on user partition takes preference. This allows Apple to update carrier bundles without releasing a whole new OS.

Structure

Carrier bundles are ZIP archives with .ipcc extension. They contain the mandatory Payload folder that includes the bundle itself and the symlink:

\Payload\
        \MyCarrier.bundle\
                         \carrier.plist - carrier settings go here
                         \Default_CARRIER_MyCarrier.png - logo for light background
                         \FSO_CARRIER_MyCarrier.png - logo for dark background
                         \Info.plist - bundle description
        \12345 - symlink to MyCarrier.bundle (12345 is MCC+MNC)

Enabling .ipcc support in iTunes

By default, iTunes allows only carrier bundle updates from Apple. However, when the "carrier-testing" preference is enabled, .ipcc files can be loaded from the user's hard drive by clicking either "Check for Updates" or "Restore" button while holding Shift (on Windows) or Option key (on Mac).

Mac OS X

1. Quit iTunes.

2. Open Terminal and paste the following command:

defaults write com.apple.itunes carrier-testing -bool true

Windows

Press Win-R and paste the following command:

"%ProgramFiles%\iTunes\iTunes.exe" /setPrefInt carrier-testing 1

Note: this command just enables the preference and exits, so iTunes won't open if it's not already running.

Type Mask

Each APN in the carrier.plist has a numeric type-mask. It is bitmask (combination of flags) that designates what the APN should be used for (eg. phone data, tethering, visual voicemail, MMS, or a combination). This table shows what each-type mask designates an APN for.

Type Mask

Value	Feature
0	Disabled
1	Data
2	Visual Voicemail (VVM)
4	MMS
48(0x30)	Tethering

For example, 55 = 1+2+4+48 means "Tethering, MMS, VVM, Data"

iPhone 3.1 Changes

As of iPhone OS 3.1b1, APN settings are now being signed to prevent tampering/modification by users. This has been implemented to stop users bypassing the carrier's designated APN for tethering that may require payment for access. This is also a concern for users of carriers that do not officially offer MMS or Tethering services for users at all. This signature-check can be circumvented by patching commcenter.

Only the APN settings are being signed; other settings can still be modified without needing to patch commcenter.

iPhone 4.0 Changes

All carrier bundle settings are now signed, not just the APN settings. To circumvent this, commcenter must now be patched. Also, the bit-mask for APN settings has changed significantly.

External Links

• Carrier Bundle Generator
• Graphical table of APN values