O'Reilly logo

Local Area High Speed Networks by Dr. Sidnie Feit

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

The ATM Cell Header

Figure 20.5 shows the format of an ATM cell header for a cell that is sent between an endpoint system and its adjacent ATM switch.

Figure 20.5. Cell header sent between an endpoint system and an ATM switch.

Currently, the first 4 bits are unused. Recall that a virtual circuit is identified by its Virtual Path Identifier (VPI) and Virtual Channel Identifier (VCI). The VPI occupies the next 8 bits. When expressed as a decimal number, the VPI value can range from 0 to 255.

The VCI occupies 16 bits. Hence, when expressed as a decimal number, the VCI value can range from 0 to 65,535. In all, there are 16,777,216 possible (VPI, ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required