According to the APNIC whois database they have recently (on 2010-02-11) allocated an IPv6 address range to City Link.
Their IPv6 prefix 2404:cc00::/32 has not been seen in the internet routing table yet, but at least they are getting prepared to the exhaustion of IPv4 addresses which will inevitably happen in near future.
My sincerest congratulations go to City Link! They are the current technology leader of IPv6 adaptation in Cambodia. This is the first range of IPv6 address space which has been ever allocated to Cambodia. I hope they will soon set up an IPv6 peering circuit to make their new address space appear in the global routing table announcements.