Get the wrong interface number from configuration descriptor

[Sonor]

Huawei E220 3G devices should have 3 interfaces in configuration descriptor ,but I just get one.

DEVICE addr 2
DEVICE descriptor:
bLength=18 bDescriptorType=device(1) bcdUSB=1.10 bDeviceClass=0
bDeviceSubClass=0 bDeviceProtocol=0 bMaxPacketSize=64 idVendor=0x12d1
idProduct=0x1003 bcdDevice=0 iManufacturer=1(\u0c05¤)
iProduct=2(\u0c05¤) iSerialNumber=0() bNumConfigurations=1

CONFIGURATION descriptor 0:
bLength=9 bDescriptorType=config(2) wTotalLength=32 bNumInterface=1
bConfigurationValue=1 iConfiguration=0() bmAttributes=a0 bMaxPower=500
mA