scp is slow on the servers Linux

When use scp to transfer some big files between nodes ,the speed is very slow,

[1] Use iperf to test network performance, it is good.

#iperf -c 3.239.5.40
iperf: ignoring extra argument -- 3.239.5.40
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
[  4] local 3.34.11.129 port 5001 connected with 3.239.5.40 port 39813
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-11.0 sec  5.38 MBytes  4.11 Mbits/sec
[  5] local 3.34.11.129 port 5001 connected with 3.239.5.40 port 39837
[  5]  0.0-10.7 sec  3.88 MBytes  3.03 Mbits/sec
[  4] local 3.34.11.129 port 5001 connected with 3.239.5.40 port 39863
[  4]  0.0-10.9 sec  3.25 MBytes  2.51 Mbits/sec
[  5] local 3.34.11.129 port 5001 connected with 3.239.5.40 port 39909
[  5]  0.0-10.6 sec  4.25 MBytes  3.36 Mbits/sec
[  4] local 3.34.11.129 port 5001 connected with 3.239.5.40 port 41279
[  4]  0.0-10.8 sec  3.88 MBytes  3.01 Mbits/sec
[  5] local 3.34.11.129 port 5001 connected with 3.239.5.40 port 41591
[  5]  0.0-11.0 sec  4.25 MBytes  3.23 Mbits/sec

[2] Use dd command to test io performance and it is also ok.

# dd if=/dev/zero of=/home/oracle/hugefile bs=10M count=100
100+0 records in
100+0 records out

1048576000 bytes (1.0 GB) copied, 0.750502 s, 1.4 GB/s


Performance of scp get effected by handling encryption/decryption packets.

Using "cipher" option in scp command to specify different encrypting protocol may speedup the file transfer.

scp -c arcfour filename root@destinationserver.com:/Destination location.


Thank you and this may help you .....:)