Packet capture question

I am dd(ing) via netcat a partition (from a host to a vm) and I am getting alot
of sender acks whith No-Ops I am assuming this is not normal anyone have some
input
Sender:
dd if=dev/sda7 | nc xxx.xxx.xxx.xxx 9000
Reciever: (here i get the nop)
nc -l -p 9000 | dd of=/dev/sda7

18:33:20.011196 IP spencer.usask.ca.35584 > engr-vserv1-vm3.usask.ca.9000: P
648704:650152(1448) ack 1 win 1460 <nop,nop,timestamp 2833435812 1037640>
18:33:20.011216 IP engr-vserv1-vm3.usask.ca.9000 > spencer.usask.ca.35584: . ack
651600 win 19506 <nop,nop,timestamp 1037641 2833435812,nop,nop,sack 1
{653048:654496}>
18:33:20.126087 IP spencer.usask.ca.35584 > engr-vserv1-vm3.usask.ca.9000: .
651600:653048(1448) ack 1 win 1460 <nop,nop,timestamp 2833436025 1037641>
18:33:20.126518 IP engr-vserv1-vm3.usask.ca.9000 > spencer.usask.ca.35584: . ack
654496 win 19548 <nop,nop,timestamp 1037669 2833436025>
18:33:20.126270 IP spencer.usask.ca.35584 > engr-vserv1-vm3.usask.ca.9000: .
651600:653048(1448) ack 1 win 1460 <nop,nop,timestamp 2833436449 1037641>
18:33:20.126561 IP engr-vserv1-vm3.usask.ca.9000 > spencer.usask.ca.35584: . ack
654496 win 19548 <nop,nop,timestamp 1037669 2833436025,nop,nop,sack 1
{651600:653048}>
18:33:20.128977 IP spencer.usask.ca.35584 > engr-vserv1-vm3.usask.ca.9000: .
654496:655944(1448) ack 1 win 1460 <nop,nop,timestamp 2833436743 1037669>
18:33:20.128992 IP engr-vserv1-vm3.usask.ca.9000 > spencer.usask.ca.35584: . ack
655944 win 19548 <nop,nop,timestamp 1037670 2833436743>
18:33:20.129731 IP spencer.usask.ca.35584 > engr-vserv1-vm3.usask.ca.9000: .
657392:658840(1448) ack 1 win 1460 <nop,nop,timestamp 2833436744 1037670>
18:33:20.129747 IP engr-vserv1-vm3.usask.ca.9000 > spencer.usask.ca.35584: . ack
655944 win 19548 <nop,nop,timestamp 1037670 2833436743,nop,nop,sack 1
{657392:658840}>
18:33:20.131305 IP spencer.usask.ca.35584 > engr-vserv1-vm3.usask.ca.9000: .
660288:661736(1448) ack 1 win 1460 <nop,nop,timestamp 2833436744 1037670>
18:33:20.131331 IP engr-vserv1-vm3.usask.ca.9000 > spencer.usask.ca.35584: . ack
655944 win 19548 <nop,nop,timestamp 1037671 2833436743,nop,nop,sack 2
{660288:661736}{657392:658840}>
18:33:20.133396 IP spencer.usask.ca.35584 > engr-vserv1-vm3.usask.ca.9000: .
655944:657392(1448) ack 1 win 1460 <nop,nop,timestamp 2833436745 1037671>
18:33:20.133418 IP engr-vserv1-vm3.usask.ca.9000 > spencer.usask.ca.35584: . ack
658840 win 19506 <nop,nop,timestamp 1037671 2833436745,nop,nop,sack 1
{660288:661736}>
Received on Tue Jan 2 20:47:43 2007