Empirical Performance of IPv6 vs. IPv4

 under a Dual-Stack Environment

 

 

 


 Home

 Measurement Setup

 Dual-Stack List

 Connectivity

 Hop Count

 RTT

 Throughput

 OS Dependence

 IPv6 Address

 Provisioning

 IPv6 Tunnel

 Performance

 Scripts

 References

 Internal Access

 

IPv6 Tunnel Performance

A. Tunnel Brokers

In this section, we investigate the network performance of IPv6 over tunnels by using the tunnel services from 3 tunnel brokers; AARNet [14] in Australia, Euro6IX [15] in Europe and Hexago/FreeNet6 in Canada [16]. While Euro6IX offers configured tunnelling services, AARNet and FreeNet6 offer 6to4 tunnels with automatic tunneling services [17].

 

B. Connectivity of Tunnels

Table VI shows that the connectivity of all tunnels are satisfactory, with all tunnel brokers showing over 90% reachability to the dual-stack sites. Among the three, FreeNet6 performed the best, with over 95% reachability, followed by Euro6IX, and then AARNet. However, the Native-IPv6 connection still outperforms all of the tunneled-IPv6 connections.

Table VI. Tunnel Connectivity Results

 

AARNet

Euro6IX

FreeNet6

NativeIPv6

Connectivity

92.52%

94.22%

95.91%

97.28%

 

C. Hop Count of Tunnels

Figs. 9 and 10 show the hop count performance of the three tunnel brokers. From our results, the average hop count for tunneled-IPv6 paths through Euro6IX, AARNet and FreeNet6 is 10.89, 14.36, 19.39 respectively, while we have reported earlier that the average hop count for Native-IPv6 paths is 15.22. These results indicate that the hop count of tunneled- IPv6 paths are dependent on the geographic locations of the tunnel brokers’ servers and their number of direct links to the IPv6 backbone.

Fig. 9. Tunnel-Native IPv6 Hop Count Results

 

Fig. 10. Distribution of Tunnel-Native IPv6 Hop Count Results

 

D. RTT of Tunnels

Figs. 11 and 12 show that while FreeNet6 has the best RTT performance, Euro6IX has the worst RTT performance among the three tunnel brokers, the opposite of the results reported for hop count of tunnels. This phenomenon has also been observed earlier in the comparison of hop count and RTT results for the Native-IPv6 vs. IPv4 performance, and in the current tunnels test, this phenomenon is due to the differences in the link accessibilities of the tunnel brokers’ servers to the dual-stack sites in our tests. Figs. 11 and 12 also show that the RTTs of tunneled-IPv6 paths are higher than those of Native-IPv6 paths. This is due to the additional delays caused by the encapsulation and decapsulation operations entailed by the tunneling process.

Fig. 11. Tunnel-Native IPv6 RTT Results

 

Fig. 12. Distribution of Tunnel-Native IPv6 RTT Results

 

E. Throughput of Tunnels

Figs. 13 and 14 show that the throughput performance of tunnels is similar to that of the RTT performance of tunnels, i.e. FreeNet6 has the best throughput performance among the three tunnel brokers. This is because the throughput of tunneled-IPv6 connections is higher when the RTT is lower. Similarly, we see that the throughput performance of Native-IPv6 connections is higher compared to that of tunneled-IPv6 connections.

Fig. 13. Tunnel-Native IPv6 Throughput Results

 

Fig. 14. Distribution of Tunnel-Native IPv6 Throughput Results

 

F. Tunnel Performance Summary

We summarized the tunneled-IPv6 network performance in Table VII where we see that FreeNet6 provides the best tunneled-IPv6 network performance. Even though its tunneled-IPv6 path has a higher hop count, in RTT and throughput, FreeNet6 achieves 40% and 30% better performance compared to AARNet and Euro6IX. Our results also show that the network performance of tunneled-IPv6 connections is nearly on par with that of Native-IPv6 connections.

Table VII. Tunnel Performance Summary

Tests

AARNet

Euro6IX

FreeNet6

(Native-IPv6)

Connectivity

92.52%

94.22%

95.91%

97.28%

Hop Count

14.36

10.89

19.39

15.22

RTT (ms)

615.87

612.05

432.20

403.36

T’put (KB/s)

82.56

72.78

123.07

107.75