Industrial Communication Systems

53-6 Industrial Communication Systems

• e 2 byte network ID

•

Destination

and source addresses either of which can be 2 or 8 byte long

•

A

1 byte DLPDU specier

•

e

DLL payload

•

A

4 byte keyed message integrity code (MIC)

•

A

2 byte ITU-T CRC16 (imposed by the IEEE 802.15.4)

In

particular,

while

the

DLL

packet

is

unencrypted,

the

MIC

is

enciphered

for

link

layer

authentication

of

the

received

datagram;

it

is

generated

and

conrmed

using

CCM*

mode

(combined

counter

with

CBC-MAC

[corrected])

in

conjunction

with

the

AES-128

block

cipher

to

provide

authentication

of

the

originator.

53.2.3 Time Keeping

It is possible to maintain the nodes clock skew ...