How to use multiple cores when replaying PCAP file data?

[wly-13]

Hi team,
When I tried to use trex to load PCAP file and replay the packets data, I found that only one core is fully used even I specified -c 10 in the command line. And the max TX rate is about 3Mpps. How can I use multiple cores to replay packets of PCAP file to get a higher TX rate? Do you have some suggestions on it? Thanks.

Below is my environment and config.

• OS: Ubuntu22.04
• Trex version: v3.00
• python script:

pcap_file = os.path.abspath(pcap_file)
self.client.push_remote(pcap_filename=pcap_file,
                                       ports=self.port,
                                       ipg_usec=self.ipg_usec,
                                       count=1)  
self.client.wait_on_traffic(ports=[0, 1])

• Trex config:

platform:
    master_thread_id: 0
    latency_thread_id: 20
    dual_if:
        - socket: 0
            threads: [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19]

[DTran0]

As I understand it, sending PCAPs is generally limited to one thread. Here is quote from manual:

The profile runs on one DP thread because it has a burst with 1 packet. (Cannot split in this case.)

It makes sense to me as PCAP has defined order of packets. You can't send second packet before first packet. Even if you split packets among cores, you would need to have some synchronization mechanism to guarantee order of packets, which would slow performance.

[wly-13]

As I understand it, sending PCAPs is generally limited to one thread. Here is quote from manual:

The profile runs on one DP thread because it has a burst with 1 packet. (Cannot split in this case.)

It makes sense to me as PCAP has defined order of packets. You can't send second packet before first packet. Even if you split packets among cores, you would need to have some synchronization mechanism to guarantee order of packets, which would slow performance.

Thanks for your reply. Is it possible that we specify different PCAP files to different cores? For example, I have 3 PCAP files. Can I set each thread to read a PCAP file? In this case, the 3 threads don't have to synchronize the order of packets.

[DTran0]

I don't think this is currently supported. Also, the push_remote method you used accepts only one PCAP file at once.

However, if you have more physical interfaces/NIC ports, you could start multiple TRex instances. Each instance could run single PCAP independently.