Chapter 1 Introduction | |
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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
Ethernet | IP | UDP | TDMoIP AAL2 Voice AAL2 Voice AAL2 Voice Ethernet | ||||||||
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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 |
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7 | Preamble |
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1 | SFD |
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6 | Destination MAC Address |
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6 | Source MAC Address |
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2 | Type |
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1 | Vers/HLEN |
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1 | Service Type |
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2 | Total Length |
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2 | Identification |
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1 | Flags/Fragment Offset (most) |
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1 | Fragment Offset (least) |
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1 | Time to Live |
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1 | Protocol |
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2 | Header Checksum |
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4 | Source IP Address |
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4 | Destination IP Address |
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2 | UDP Source Port |
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2 | UDP Destination Port |
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2 | UDP Message Length |
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2 | UDP Checksum |
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... | Payload |
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4 | CRC |
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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.
Functional Description |
