Altera Low Latency Ethernet 10G MAC - Manual (Page 51)

Figure 3-24: PTP Packet 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
Payload
10 Octets
domainNumber
messageLength 2 Octets
1 Octet
0..1500/9600 Octets
CRC
Note:
(1) For packets with VLAN or Stacked VLAN tag, add 4 or 8 octets offsets before the length/type field.
4 Octets
(1)
PTP Packet over UDP/IPv6
The following figure shows the format of the PTP packet transported over the UDP/IPv6 protocol.
Checksum calculation is mandatory for the UDP/IPv6 protocol. You must extend 2 bytes at the end of the
UDP payload of the PTP packet. The MAC function modifies the extended bytes to ensure that the UDP
checksum remains uncompromised.
UG-01144
2014.12.15
PTP Packet over UDP/IPv6 3-29
Functional Description of LL Ethernet 10G MAC Altera Corporation
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