IPmux-1/1EInstallation and Operation Manual

Chapter 1 Introduction

 

 

MAC

Layer

LLC

Layer

IP Layer

UDP

Layer

Data

Layer

MAC

Layer

Table 1-2. Ethernet Frame Structure

 

 

Field length (bytes)

Field

 

 

 

 

7

Preamble

 

 

 

 

1

SFD

 

 

 

 

6

Destination MAC Address

 

 

 

 

6

Source MAC Address

 

 

 

 

2

Type

 

 

 

 

1

Vers/HLEN

 

 

 

 

1

Service Type

 

 

 

2

Total Length

 

 

 

2

Identification

 

 

 

1

Flags/Fragment Offset (most)

 

 

 

1

Fragment Offset (least)

 

 

 

1

Time to Live

 

 

 

1

Protocol

 

 

 

2

Header Checksum

 

 

 

4

Source IP Address

 

 

 

4

Destination IP Address

 

 

 

2

UDP Source Port

 

 

 

2

UDP Destination Port

 

 

 

2

UDP Message Length

 

 

 

2

UDP Checksum

 

 

 

...

Payload

 

 

 

4

CRC

 

 

 

 

Note: IEEE 802.1p&q VLAN Tagging (additional 4 bytes if enabled)

Note: The UDP source port field is used to transfer the destination bundle number in static and dynamic CAS modes.

Functional Description

1-17

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Cisco Systems IPMUX-1E operation manual Layer IP Layer, Layer Data, Ethernet Frame Structure, Field length bytes