Hi max,
first of all you need to know what is the telekom/vodafone network.
For exemple, device C819(H)G+7-K9 and C819HGW+7-E-K9 and C819HGW+7-A-A-K9 and C819HGW+7-A-N-K9
support these networks:
• HSPA+: 850, 900, 1900, and 2100 MHz (forward link up to 21Mbps; reverse link up to 5.76 Mbps)
• Backward compatibility:
• HSDPA: 850, 900, 1900, and 2100 MHz (forward link up to 21 Mbps; reverse link up to 384 kbps)
• UMTS: 850, 900, 1900, and 2100 MHz (forward link up to 2.0 Mbps; reverse link up to 384 kbps)
• EDGE: 850, 900, 1800, and 1900 MHz (forward link up to 236 kbps; reverse link up to 124 kbps)
• GPRS: 850, 900, 1800, and 1900 MHz
You can find out other possibilites at:
http://www.cisco.com/en/US/prod/collateral/routers/ps380/datasheet_c78-680001.html
Regards,