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Degraded throughput with Jambo frame ( MTU 9000Bytes) #21

Closed dejeneboru closed 5 years ago

dejeneboru commented 5 years ago

Hi,

I have two Linux computers connected to NetFPGA-SUME board. I configured an MTU size of 9000 Bytes for the Linux nodes and implemented a simple P4 program which does port in port out.

I used an IPerf to test the rate between the Linux nodes and obtained literally zero throughput.

iperf3 -c 20.0.2.4 -i 1 -t 60 Connecting to host 20.0.2.4, port 5201 [ 4] local 18.0.1.4 port 41528 connected to 20.0.2.4 port 5201 [ ID] Interval Transfer Bandwidth Retr Cwnd [ 4] 0.00-1.00 sec 297 KBytes 2.43 Mbits/sec 3 8.74 KBytes [ 4] 1.00-2.00 sec 0.00 Bytes 0.00 bits/sec 1 8.74 KBytes [ 4] 2.00-3.00 sec 0.00 Bytes 0.00 bits/sec 0 8.74 KBytes [ 4] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 1 8.74 KBytes ^C[ 4] 4.00-4.93 sec 0.00 Bytes 0.00 bits/sec 0 8.74 KBytes

A tcpdump at the Linux nodes shows the following listening on enp101s0f1, link-type EN10MB (Ethernet), capture size 262144 bytes 15:38:15.845825 IP truncated-ip - 7502 bytes missing! (tos 0x2,ECT(0), ttl 64, id 14314, offset 0, flags [DF], proto TCP (6), length 9000) 18.0.1.4.41524 > 20.0.2.4.5201: Flags [.], seq 2549289604:2549298552, ack 967224288, win 210, options [nop,nop,TS val 2138173070 ecr 4149489059], length 8948

Then, I added the IP checksum computation to the P4 code which has not solved the problem.

I don't see this problem with MTU of 1500 bytes.

What should I do to overcome this limitation? Is the MTU size fixed to a maximum of 1500 bytes for the NetFPGA-SUME board?

Thanks,

/Dejene

AnotherKamila commented 5 years ago

See https://github.com/NetFPGA/P4-NetFPGA-live/issues/16 -- jumbo frames are not supported, you'd have to modify the Verilog wrappers to add support for them.

dejeneboru commented 5 years ago

See NetFPGA/P4-NetFPGA-live#16 -- jumbo frames are not supported, you'd have to modify the Verilog wrappers to add support for them.

Thanks, Kamila for confirming. I have also tried to modify the Verilog files but no success.

So I am closing this issue.

anmomu92 commented 2 years ago

See NetFPGA/P4-NetFPGA-live#16 -- jumbo frames are not supported, you'd have to modify the Verilog wrappers to add support for them.

Thanks, Kamila for confirming. I have also tried to modify the Verilog files but no success.

So I am closing this issue.

When modifying the wrappers and testing with iperf again, did you have to reload the bitstream into the FPGA because the design stopped working when sending frames of 9000 bytes?