Industrial Communication Systems

6LoWPAN: IP for Wireless Sensor Networks and Smart Cooperating Objects 51-11

51.5.5.2 UDP Header Compression

Further,

protocol-specic

compressions

in

addition

to

the

above-presented

IPv6

header

compression

are

summarized

in

the

RFC4944

HC2

encoding

format.

In

the

current

version

of

the

6LoWPAN

specica-

tion,

on

ly

th

e

HC

_UDP

sc

heme

is de

scribed

fo

r

HC

2

en

coding.

A

standard

UDP

header

consists

of

2

octets

for

the

source

port

of

the

message,

2

octets

for

the

desti-

nation

port,

2

octets

indicating

the

length

of

the

frame,

and

2

octets

for

the

checksum

eld.

is

sums

up

in

8

octets,

which

can

be

compressed

to

4

octets

in

6LoWPAN

networks.

Like

the

Hop

Limit

eld

in

the

HC1

header,

the

checksum

eld

cannot

be

compressed

and

must

be

carried

in-l ...