[dpdk-users] How to specify packet size of testpmd

[Xu, Chenjie]

Hi Harry,
Thank you for your email! I'm trying to use pktgen now. Do you know which command should be used to specify the packet size for pktgen?

Best Regards,
Xu, Chenjie

-----Original Message-----
From: Van Haaren, Harry <harry.van.haaren at intel.com> 
Sent: Thursday, July 9, 2020 5:51 PM
To: Xu, Chenjie <chenjie.xu at intel.com>; users at dpdk.org
Subject: RE: [dpdk-users] How to specify packet size of testpmd

> -----Original Message-----
> From: users <users-bounces at dpdk.org> On Behalf Of Xu, Chenjie
> Sent: Thursday, July 9, 2020 10:26 AM
> To: users at dpdk.org
> Subject: [dpdk-users] How to specify packet size of testpmd
> 
> Hi all,
> Do you know how to specify the packet size when using testpmd to test 
> the network performance?

Hi,

Usually, testpmd just forwards the packets it receives. Testpmd itself is not a "proper" traffic generator, but it does have some capabilities to send some traffic before starting its rx-tx behavior. 

The command is "start tx_first" and this will by default use a small packet size.
https://doc.dpdk.org/guides/testpmd_app_ug/testpmd_funcs.html#start-tx-first

There are a number of more powerful DPDK based traffic generators available, if you require more features. Examples are pktgen, trex, moongen.

Of course, it is also possible to modify a sample application like example/skeleton to send a specific traffic type, as your particular benchmarking might require.

> Best Regards,
> Xu, Chenjie

Hope that helps, -Harry