Iridium Certus terminals use the second generation Iridium NEXT satellites to provide broadband internet access up to 704 kbps (down) / 352 kbps (up). IP data is available on a best effort shared bandwidth effort and is billed by the megabyte. Each terminal has 3 voice lines and superb sound quality. Each of the 3 phone lines can be configured as a standard line, a standard line with US number access or as a crew line for use with prepaid scratch cards. Streaming data suitable for video and other high performance applications is billed by the minute of connection time and is available at data speeds up to 256 kbps. Iridium Short Burst Data (SBD) is available as an optional service.