Altera Triple Speed Ethernet MegaCore Function - Manual (Page 76)

Figure 4-28: PTP Frame over UDP/IPv4
MAC Header
UDP Header
IP Header
PTP Header
Time To Live
Protocol = 0x11
Version | Internet Header Length
Differentiated Services
Flags | Fragment Offsets
1 Octet
1 Octet
2 Octets
1 Octet
1 Octet
Header Checksum 2 Octets
Source IP Address 4 Octets
Destination IP Address 4 Octets
Options | Padding 0 Octet
Source Port 2 Octets
Destination Port = 319 / 320 2 Octets
Identification
Total Length 2 Octets
2 Octets
Length/Type = 0x0800
Source Address
Destination Address
2 Octets
6 Octets
6 Octets
Checksum
Length
2 Octets
2 Octets
flagField
correctionField
transportSpecific | messageType
reserved | versionPTP
reserved
1 Octet
1 Octet
1 Octet
2 Octets
8 Octets
reserved 4 Octets
SourcePortIdentify 10 Octets
sequenceId 2 Octets
controlField 1 Octet
logMessageInterval 1 Octet
TimeStamp 10 Octets
domainNumber
messageLength 2 Octets
1 Octet
CRC 4 Octets
(1)
0..1500/9600 Octets Payload
Note to Figure 4-28 :
1. For frames with VLAN or Stacked VLAN tag, add 4 or 8 octets offsets before the length/type field.
PTP Frame over UDP/IPv6
Checksum calculation is mandatory for the UDP/IPv6 protocol. You must extend 2 bytes at the end of the
UDP payload of the PTP frame. The MAC function modifies the extended bytes to ensure that the UDP
checksum remains uncompromised.
Functional Description Altera Corporation
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PTP Frame over UDP/IPv6 4-40
2014.06.30