**2.2.1 Statistics**

82 Telecommunications Networks – Current Status and Future Trends

The bandwidth redistribution problem having been solved, attention could be focused on

Fig. 3 shows how queuing algorithms were applied. A root node (qdisc) was created in the imq0 interface; class 1:1 was added in order to define the total bandwidth (100 Mbit/s in this case). Subclasses were then defined for the management of single connections, each

Note that a higher QoS could be achieved if the SFQ (Stochastic Fair Queuing) were applied,

In order to manage priority of single flows, a hierarchic structure was created within each

As in the former case, several subclasses were added to the root node (qdisc), each with a minimum and maximum bandwidth; the SFQ algorithm was applied afterwards. A u32filter list is defined in the root node of each interface, so as to drive single packets on the class they pertain to on the basis of their protocol. Packets were initially divided by the CLASSIFY TARGET tool according to the connection; a further division was then made by

Besides, the identifiers range is 1:10000 and 1:65535 in hex, so the highest attention must be

iptables -t mangle -A POSTROUTING -j CLASSIFY --set-class x:y

specifying the minimum guaranteed (rate) and maximum at disposal (ceil).

so as to manage single flows through a Round Robin policy.

paid to each class handles. The following synatx was adopted:

In this way, filters could be avoided and everything is managed by iptables.

flow priority within each connection.

u32filter+MARK on the basis of protocols.

Fig. 3. hierarchical QoS management.

PPPN interface.

The platform allows to visualize information about the infrastructure and its use and, in consequence, to make statistics about connected users and their traffic volume.

Fig. 4, for instance, refers to all the users' total connection time. For the sake of compactness, only a small excerpt was reported.

Diagrams are also available describing the system components, such as CPU load, network load and many others.


Fig. 4. small excerpt from all the users' total connection time.

As far as each user is concerned (Fig. 5), the following data can be monitored: connections, data volumes exchange, diagrams about his or her traffic and, as indicated by law, packets logging.The authentication system adopted is Radius and traffic is encapsulated through the PPPoE protocol. In consequence, a PPP tunnel is active between each user and the server.
