Discovering the existence of an NE

STEP 1 – discovering the existence of an NE

Deep discovery starts by discovering the existence and, if possible, the type of equipment available in the network. Users specify a seed IP address/hostname, a subnet mask for the seed IP, and a set of possible ports to define the boundaries of their network. Users can also specify protocol-specific parameters, community strings in SNMP, or access parameters for TL1 devices. The Discovery service then determines the network address, calculates the set of all possible IP addresses for any machine on that network, and queries the appropriate addresses. For TL1-managed devices, Netcool/Precision TN sends a RTRV-HDR command; for SNMP-managed devices, Netcool/Precision TN tries an SNMP get request on the sysObjectId MIB value.

When the Discovery service receives a response from a device, it tries to identify the type of device at that address. For TL1-managed devices, Netcool/Precision TN extracts the target ID (TID) or name of the NE from the RTRV-HDR response. If the NE uses the CLLI naming convention, the Discovery service can use this information to extract the NEType. Alternatively, some TL1 devices receive requests on a unique port. This information can be configured in the NEType file so that the Discovery service can use this to identify the device. For SNMP NEs, each NEType file has a unique SysObjectId value. The Discovery service matches the sysObjectId returned by the NE with the value of this variable in the appropriate NEType to identify the device.

STEP 2 – discovering the contents of an NE

After discovering the existence of an NE, the Discovery service then instructs the Inventory service to retrieve all the resources in the NE. The NEType determines how this information is retrieved. For example, for TL1-managed NEs, the Inventory service issues a RTRV-EQPTcommand with wildcards to retrieve the rack, shelf, and card information; for SNMP-managed NEs, it does an SNMP get on the tables in the ENTITY-MIB.

Then, based on the cards that the Inventory service has retrieved, the Facility service looks for all the physical termination points (PTPs) on these cards, and then for all the logical resources; that is, the connection termination points (CTPs) for each PTP that is provisioned.

The Network Connection service locates all the cross-connects configured on each NE. Netcool/Precision TN discovers not just the existence of the entities, but also their properties.

STEP 3 – discovering and resolving network topology

Based on the information discovered by the Inventory and Facility services, Netcool/Precision TN queries the NEs to build a comprehensive topological map of the network. Devices from the same manufacturer that use similar technology might have knowledge of the NEs that are physically connected to the device. For example, some ATM devices, such as the SeaBridge XpressPassTM, support the PNNI protocol. This protocol enables an NE to communicate with the other NEs it is connected to topologically. PNNI-aware NEs can thus be queried for the topological connections they are a part of. For

4 Netcool/Precision for Transmission Networks 5.5 Administration Guide