Large services often serve customers from regional servers (Google does that for sure), whereas the direct connection spans half of Europe. I doubt OTE has a direct peering with Virgin UK, so there are most likely multiple network paths between the two, making packet overtaking, resulting in shuffled packet order at arrival, possible.
I suffer no romantic illusions about ISPs, but I follow my mum's advice - only waste your time looking for evil intention where mere stupidity is not sufficient as an explanation. Nevertheless, it is possible that the ISP applies some specific treatment to the VPN traffic. But if that treatment targets something, I'd rather expect it to be P2P file sharing networks than VPNs. P2P file exhausts network bandwidth whilst itself it doesn't need fast responses, so slowing it down in order to allow interactive services to perform better is something I can understand. And slowing down of TCP traffic inside VPNs may be a neglected side effect if the slowdown is achieved by tampering with small UDP packets.
The sniffing would consist in the following steps:
- at both routers, run /tool sniffer set file-limit=50000 file-name=l2tp-ipsec-xxx.pcap (replace xxx by either client or server as per the role of the CCR in the L2TP setup)
- start the bandwidth measurement using a single connection and TCP and let the throughput stabilize
- use /ip ipsec active-peers print in London to find out from what public IP the connection arrives from Tinos, the contents of the REMOTE-ADDRESS column is important, not of the ID one)
- at both routers, run /tool sniffer quick ip-address=the.public.ip.of.the.other.ccr
- after some 10 seconds from starting it at the second one, stop it at both (so we should have 10 seconds of traffic captured at both)
Then download the files and think how to hand them over. Since private messaging is off again, I suggest you send me your e-mail address according to lines 14-16 of
this howto (you use your e-mail address instead of the
--pass--). Or you may post the files on some file sharing service with a password, put a link to it here and send me just the passwords to the files encrypted as above.
My public key is
public key code
-----BEGIN PUBLIC KEY-----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-----END PUBLIC KEY-----