Altera 10-Gbps Ethernet MAC MegaCore Function - Manual (Page 93)

7–26 Chapter 7: Functional Description
IEEE 1588v2
10-Gbps Ethernet MAC MegaCore Function User Guide February 2014 Altera Corporation
7.9.4.2. PTP Packet over UDP/IPv4
Figure 7–15 shows the format of the PTP packet encapsulated in UDP/IPv4.
Checksum calculation is optional for the UDP/IPv4 protocol. The 1588v2 TX logic
should set the checksum to zero.
Figure 7–15. PTP Packet over UDP/IPv4
Note to Figure 7–15 :
(1) For packets with VLAN or Stacked VLAN tag, add 4 or 8 octets offsets before the length/type field.
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
Payload
10 Octets
domainNumber
messageLength 2 Octets
1 Octet
0..1500/9600 Octets
CRC 4 Octets
(1)