OpenVPN Traffic rate for "tun0" higher than set maximum 10 Mbit


OpenVPN, road warriod, tun0, proto UDP.
I just spoted in /var/log/messages these warnings (?)

vnstatd[31177]: Traffic rate for “tun0” higher than set maximum 10 Mbit (20s->27262976, r30823943 t10015772, 64bit:1), syncing.

Here are the tun0 parameters: speed is 10 Mb

ethtool tun0
Settings for tun0:
Supported ports: [ ]
Supported link modes: Not reported
Supported pause frame use: No
Supports auto-negotiation: No
Advertised link modes: Not reported
Advertised pause frame use: No
Advertised auto-negotiation: No
Speed: 10Mb/s
Duplex: Full
Port: Twisted Pair
Transceiver: internal
Auto-negotiation: off
MDI-X: Unknown
Current message level: 0xffffffa1 (-95)
drv ifup tx_err tx_queued intr tx_done rx_status pktdata hw wol 0xffff8000
Link detected: yes

Question - is there any setting I can apply to tun0 to set it up to 100 Mbit?
Second: should I be worried that my tun0 is at 10 Mbit - I do get constantly above 10 Mbit over OpenVPN so I don’t thonk it really matters!?

tun0 adapter is virtual. So negotiation does not matter that much…