eCPRI Intel® FPGA IP User Guide

ID 683685
Date 12/01/2024
Public
Document Table of Contents

4.2.1. Packet Classifier

The packet classifier parses the incoming Ethernet frame to identify the types of incoming packets. The incoming packets could be eCPRI packet, PTP packet, or C&M packet with different types of frames ( e.g., standard Ethernet frame, IPv4, and etc.)

Packet classifier redirects eCPRI packets to next component for further processing and classifies a packet as eCPRI packet if all the condition listed in the table below met. The packet classifier sends all non-eCPRI packets and eCPRI packets with non-matching MAC address fields to external Avalon® streaming interface.
Table 13.  Ethernet Frame Format (User Data over Ethernet)
Number of Bits RX Frame Condition
48 MAC Destination address Destination MAC address matches receiver source MAC address.
48 MAC Source address Do not check.
32 (Optional) VLAN tag Packet parser checks for VLAN tag and adjust the offset accordingly.
32 (Optional) Stack VLAN tag Packet parser checks for SVLAN tag and adjusts the offset accordingly.
16 Ethertype (2 Bytes)= IP

Ethertype is equal to 0xAEFE

If eCPRI message transmitted over IP/UDP, the IP supports only IPv4 with UDP.
Table 14.  Ethernet Frame Format with IPv4 (User Data over IP)
No. of Bits IPv4 Header Condition
48 MAC destination address Destination MAC address matches receiver source MAC address.
48 MAC source address Do not check.
32 (Optional) VLAN Tag Packet parser checks for VLAN tag and adjusts the offset accordingly.
32 (Optional) Stack VLAN Tag Packet parser checks for SVLAN tag and adjusts the offset accordingly.
16 Ethertype (2B) = IP Ethertype must be 0x0800 for IPv4.
4 Version Version must be 4'h4.
4 Internet Header Length The value must be 4'h5. The IP does not support IPv4 "Options" field.
6 Differentiated Services Code Point (DSCP) Do not check.
2 Explicit Congestion Notification (ECN) Do not check.
16 Total length Do not check.
16 Identification Do not check.
3 Flags Do not check.
13 Fragment offset Do not check.
8 Time To live Do not check.
8 Protocol The protocol value must be equal to 0x11 for IPv4 with UDP.
16 Header checksum Do not check.
32 Source address Do not check.
32 Destination address Destination IP address matches receiver source IP address.
16 Source port Do not check.
16 Destination port Destination port number matches receiver UDP port number.
16 Length Do not check.
16 Checksum Do not check.