NTttcp tests

[itsecasc]

sorry if s may have a quick question slighty offtopic but somwhat related - about NTttcp tests
i noticed my SEND / RECEIVE node having same speed (d'uh) but the RECEIVE node has larger avg MTUs (jumbo enabeld)
any idea whats causing this ? (if tested the other direction, REC>SND frames again) ((does it even matter)) ?

Code: Select all

C:\stuff>NTttcp.exe -r -m 1,0,172.16.110.31 -a 6 -t 15
Thread  Time(s) Throughput(KB/s) Avg B / Compl
======  ======= ================ =============
     0   15.016       115857.314     42807.251
#####  Totals:  #####
   Bytes(MEG)    realtime(s) Avg Frame Size Throughput(MB/s)
================ =========== ============== ================
     1698.938892      15.015       9003.126          113.149
Throughput(Buffers/s) Cycles/Byte       Buffers
===================== =========== =============
             1810.391       5.605     27183.022
DPCs(count/s) Pkts(num/DPC)   Intr(count/s) Pkts(num/intr)
============= ============= =============== ==============
     6736.131         1.956        9688.112          1.360
Packets Sent Packets Received Retransmits Errors Avg. CPU %
============ ================ =========== ====== ==========
       97353           197872           8      0      4.761

Code: Select all

C:\stuff>NTttcp.exe -s -m 1,0,172.16.110.31 -a 6 -t 15
Thread  Time(s) Throughput(KB/s) Avg B / Compl
======  ======= ================ =============
     0   15.015       115860.673     65536.000
#####  Totals:  #####
   Bytes(MEG)    realtime(s) Avg Frame Size Throughput(MB/s)
================ =========== ============== ================
     1698.875000      15.015       1455.531          113.145
Throughput(Buffers/s) Cycles/Byte       Buffers
===================== =========== =============
             1810.323       0.796     27182.000
DPCs(count/s) Pkts(num/DPC)   Intr(count/s) Pkts(num/intr)
============= ============= =============== ==============
     6496.170         0.995        8674.459          0.745
Packets Sent Packets Received Retransmits Errors Avg. CPU %
============ ================ =========== ====== ==========
     1223883            97023          21      0      0.676

[Al (staff)]

Hello Itsecasc,

Could you provide a little more input here?

What configuration you have. Maybe you have a switch, which does not support jumbo frames (or they are disabled). Thus, sent packet is default (1500) size.

[itsecasc]

test setup are two proliant microserver each one with HP Ethernet 1Gb 2-port 332i Adapter running hp's vmware 6u2 latest patch and mtu 9000 on the vswitches.
direct connect, not using a switch. regular rj45 cable connected - it sure should auto mdi-x
os was w2k12r2 mtu on nic jumboed, using vmnetx3

[Al (staff)]

Hello Itsecasc,

Did you try to ping this node with jumbo packet from your switch or other node?