The following service categories have been defined by Asynchronous transfer mode:

1) Real-time service:

• Constant bit rate (CBR)
• Real-time variable bit rate (rt-VBR)

2) Non-real-time service:

• Non-real-time variable bit rate (nrt-VBR)

• Available bit rate (ABR)

• Unspecified bit rate (UBR)

• Guaranteed frame rate (GFR)

1) Real-time service: Real-time applications typically involve …