RAD Data comm Vmux-2100 operation manual Layer IP Layer, Layer Data, Ethernet Frame Fields

Chapter 1 Introduction Vmux-2100Installation and Operation Manual

Ethernet Frame

At a later stage, the TDMoIP frame becomes a part of the standard Ethernet frame, which also includes a UDP header, IP header and MAC. The Ethernet frames are forwarded to the Ethernet switch, which sends them to one of the main links: 10/100BaseT or E1/T1. Figure 1-7illustrates the structure of the Vmux-2100 Ethernet frame. Table 1-1describes the fields of the Vmux-2100 Ethernet frame.

Ethernet IP UDP TDMoIP AAL2 Voice AAL2 Voice AAL2 Voice Ethernet

Figure 1-7. Ethernet Frame Structure

MAC

Layer

LLC

Layer

IP Layer

UDP

Layer

Data

Layer

MAC

Layer

Table 1-1. Ethernet Frame Fields

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

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

Note: The UDP source port field is used to transfer a destination bundle number.

1-8 Functional Description