PACKETS AND FRAMES

PACKETS:
Packet is a generic term that refers to small block of data. Packet have different
format. Each hardware uses different packet format.
FRAME:
A frame or hardware frame denotes a packet of a specific format on a specific
hardware technology.
FRAME FORMAT:
We need to define a standard format for data to indicate the beginning and end of
the frame. Header and tail are used to frame the data as shown in the figure below.


We see that in the figure soh and eot are used to denote the start of header and end of tail.

FRAMING IN PRACTICE:
In practice there is a disadvantage of overhead. To avoid the no delay between
two frames each frame sends an extra character between block of data.
The framing in practice also has some transmission problems just like:

• Missing eot indicates sending computer crashed.
• Missing soh indicates receiving computer missed beginning of message.
• Bad frame is discarded