"The tourism figures for the BRIC countries, in particular for Russia, are very promising for the tourism industries of the host countries and destinations," said Martin Buck, a German travel industry executive.
The case of RTT and packet loss rate is complicated, which are related to path loads and destination host loads.
Specifically, we investigate potential effects of three factors: integration into the host society, emigrant networks, and destination characteristics.
Definition 3. Port Importing Network Activity Y i : for all network flows destining to port i in a measurement time window, the ratio of the difference between the numbers of related source and destination hosts and the number of all the port i related hosts is called port i's Port Importing Network Activity Y i. Y i = DSI P i - DDI P i DSI P i + DDI P i (9).
Definition 2. Port Exporting Network Activity X i : for all network flows leaving from port i in a measurement time window, the ratio of the difference between the numbers of related source and destination hosts and the number of all the port i related hosts that send traffic is called port i's Port Exporting Network Activity X i. X i = SDI P i - SSI P i SDI P i + SSI P i (8).
In measuring data, if the number of a port's related export and import hosts is small, then because of the tiny random difference between the numbers of source and destination hosts, some inactive port will be made with big random difference between port's inward and outward communication metric.
The key idea of our approach is treating the network, seen by specific source and destination hosts, as a black-box, and modeling the end-to-end packet delay dynamics using system identification, having been throughly used in the field of control engineering.
Definition 6. Port Overall Network Activity D i : for a given port i during a measurement time window, the whole numbers of port i's related source and destination hosts.
In this case the migrating VMs are attached to the same file system, available at both source and destination hosts, so that there is no need to copy disk images.
The network state consistency issue is easily solved in a local cloud environment: in fact, since each VM is connected via a virtual bridge to the same physical LAN at both source and destination hosts, it will keep the same IP address and, when the execution is resumed at the destination, a gratuitous ARP packet is sufficient to make all switches and neighbors aware of the new VM location.
