RAD Data comm IPmux-11 - Manual (Page 23)

Installation and Operation Manual Chapter 1 Introduction
IPmux-11 Ver. 2.00 Functional Description 1-9
Table 1-2. TDMoIP 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
The UDP Source Port value calculation depends on the selected TDMoIP version
(1 or 2):
• TDMoIP version 2: The UDP Source Port value equals 0x2000 + Destination
Bundle Number, it is always greater than 8192.
• TDMoIP version 1:
During normal operation the UDP Source Port value equals Destination
Bundle Number + 1 (for example, for bundle 1 the UDP Source Port equals
2). The allowed range for the UDP Source Port values in the normal state is
from 0 to 8191.
If a bundle is in the local fail state, the MSB of the UDP Source Port is set to
1 to indicate the local fail state to the remote equipment. In this case the
UDP Source Port value equals 0x8000 + Destination Bundle Number + 1.
The UDP Source Port value in the local fail state is always greater than
32768.
ETH
Layer
IP Layer
ETH
Layer
UDP
Layer
Data
Layer
LLC
Layer
Note: IEEE 802.1p&Q VLAN
Tagging (additional 4 bytes if
enabled)
The UDP source port field is
used to transfer a destination
bundle number. See Note
below.
Note