Bloat » Cerowrt

6to4 and 6rd performance varies dramatically across vendors. It would be good to measure this in a less adhoc fashion.

I was seeing about 20% difference in speed on the following two tests over comcast, between the 2002 and 2001 networks. Over FIOS... 6to4 is 53X slower.

IPv4 TEST:¶

d@cruithne:~$ iperf t 60 -c huchra.bufferbloat.net
-----------------------------------------------------------
Client connecting to huchra.bufferbloat.net, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.1.181 port 56963 connected with 149.20.54.237 port 5001
[ 3] 0.0-60.0 sec 176 MBytes 24.5 Mbits/sec

IPv6 test¶

d@cruithne:~$ iperf t 60 -V -c huchra.bufferbloat.net
-----------------------------------------------------------
Client connecting to huchra.bufferbloat.net, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 3] local 2002:47a2:f305:1::2 port 34130 connected with 2001:4f8:3:36:2e0:81ff:fe49:2cfe port 5001
[ 3] 0.0-63.6 sec 3.48 MBytes 459 Kbits/sec

From this location, it's about 165 ms to huchra via the nearest 6to4 router on FIOS (vs about 85ms on ipv4).

Going pure 6to4 replicates the result ratio I was getting with comcast:

d@cruithne:~$ iperf V -t 60 -c 2002:9514:3640:36:2e0:81ff:fe23:90d3
-----------------------------------------------------------
Client connecting to 2002:9514:3640:36:2e0:81ff:fe23:90d3, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 3] local 2002:47a2:f305:1::2 port 37667 connected with 2002:9514:3640:36:2e0:81ff:fe23:90d3 port 5001
[ 3] 0.0-60.2 sec 160 MBytes 22.3 Mbits/sec

Which basically accounts for the size of the ack packets being larger and leveraging the existing ipv4 routing scheme throughout rather than jumping to the native ipv6 network.