[CentOS] udp question

i all

I use linux as GiGE router and have 6 NIC on it
Those days the NIC interrupt takes around 100% CPU but the system is 4G memroy and 8 CPU. I can't see any error packet in this NIC interface too

After I block the udp, the %CPU drops. but the UDP only takes around 8M in general

We use UDP traffic for voice.

Do you have any suggestion ?  increase the kernel parameter?

Thank you so much
       
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