A network monitor monitors traffic on a dedicated data network passively. The data network connects network controllers which control associated network elements of an automatically switched optical transport network. The network controllers regularly advertise their locally stored network topology and status information using a predefined protocol. The monitor filters protocol frames of this predefined protocol type and extracts therefrom information about the topology and status of the transport network and displays these information graphically to a user.
1. A network monitor connected to a first dedicated packet-switched data network for passively monitoring traffic on the first dedicated packet-switched data network to filter protocol frames in the first dedicated packet-switched data network in order to extract information about a network topology and status of a second automatically switched optical transport network, the first dedicated packet-switched data network connecting network controllers controlling associated network elements of the second automatically switched optical transport network, said network monitor comprising:
a module to filter protocol frames of a predefined protocol type in the first dedicated packet-switched data network by which said network controllers advertise a network topology and status of the second automatically switched optical transport network; and
a module to extract from the filtered protocol frames transmitted in the first dedicated packet-switched data network information about the network topology and status of the second automatically switched optical transport network and display the network topology and status information of the automatically switched optical transport network graphically to a user,
wherein the module to filter protocol frames and the module to extract from the filtered protocol frames information about the network topology are elements of the network monitor independent from and not integrated into the network controllers controlling the associated network elements.
2. A network monitor according to claim 1 , comprising a sniffer module configured to capture data from a data network connection in the first dedicated packet-switched data network, or read data from a previously captured file and to pass said data to an evaluation module programmed to extract said topology and status information of the second automatically switched optical transport network from the data and to display the network topology and status information of the second automatically switched optical transport network graphically on a display.
3. A network monitor according to claim 1 , wherein said frames of a predefined protocol type are OSPF frames comprising information about routing controllers, border nodes of domains and links to and from the border nodes.
4. A network monitor according to claim 1 , wherein said network monitor is further configured to represent domains as indicated by their corresponding routing controllers as smaller circles along a circle line of a larger circle.
5. A network monitor according to claim 1 , wherein said network monitor is further configured to represent links with idle capacity in a first color and busy links in a second color.
6. A network monitor according to claim 1 , further comprising a command line interface connected to one of the network controllers to program said connected network controller to broadcast a request for an immediate update of topology and status information and/or to program said connected network controller to set up a new connection and/or perform other configuration changes in the second automatically switched optical transport network.
7. A network monitor according to claim 1 , wherein said network monitor is further configured to detect a mismatch between any two filtered protocol frames and display these frames as ASCII text to a user.
8. A method of passively monitoring traffic on a first dedicated packet-switched data network to filter protocol frames in the first dedicated packet-switched data network in order to extract information about a network topology and status of a second automatically switched optical transport network, the first dedicated packet-switched data network connecting network controllers controlling associated network elements of the second automatically switched optical transport network; said method comprising the steps of:
filtering protocol frames of a predefined protocol type in the first dedicated packet-switched data network, by a network monitor, by which said network controllers advertise a network topology and status of the second automatically switched optical transport network;
extracting from the filtered protocol frames transmitted in the first dedicated packet-switched data network, by the network monitor, information about the network topology and status of the second automatically switched optical transport network and
displaying the network topology and status information of the second automatically switched optical transport network graphically to a user,
wherein the steps of filtering, extracting and displaying are performed independently from the controlling of the associated network elements and the advertising of the network topology and the status by the network controllers.