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

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