Expansion Node Manager Module Set
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Features
- Internal Stratum 3 Clock with Holdover
- Hitless Switchover between Online and Standby Module
- Ability to Accept Multiple BITS Clock inputs
- Alarm Contact Closures
- Support for 8 Concurrent Users
Introduction
The Expansion Node Manager (XNM) controls operation of the DNX-88 system and the local adjunct PSX-5300 Protection Switch. The XNM is located in Nest 1, the same chassis as the Expansion Cross-Connect modules, and provides the management interfaces to external devices. It also communicates with Nests 2-8 via the XCC and XLC modules that make up the remainder of the seven chassis that comprise the node. The XNM provides distributed intelligence in a fault tolerant configuration, while granting the user the luxury of managing a single network element.
This third-generation module set adds significant features. FLASH memory has been increased to support the numerous connections possible in the expansion node environment. An additional communication path is now available to support a new 1 Mbps supervisory channel between the XNM and XCC modules. The XNM consists of a Controller (front) module and an interface (rear) module, both single slot cards. The Controller module is half height; the interface module, a full slot height.
Capabilities and Features
The XNM utilizes dual communication busses on the local DNX midplane to control modules within the nest and provide several methods for communicating with and controlling the DNX system. The intuitive VT100 terminal interface offers direct or remote connectivity. Remote connections to the System Manager can be made using the internal modem or by Telnet. The system devices and ports also can be configured, monitored, diagnosed, and provisioned using Simple Network Management Protocol (SNMP).
The DNX supports up to three user-defined clock sources: Network Synchronized Timing, Internal Timing, or Port Timing. Network Synchronized Timing includes line timing provided by DNX channel cards or by a stand-alone source, such as a Timing Signal Generator. The Internal timing source is a Stratum 3 clock, which can be used as a reference to generate system-clocking signals. In the event of a reference clock failing, the DNX automatically selects an alternate input based on the source clock configuration setting. Port timing can be provided by any of the following optional channel cards if located in the local Nest 1: Octal T1/E1 (ports 1-8), Octal High Speed (ports 1-8), T3 (T1 ports 1-28), and Quad T1 (ports 1-4).
When the Internal timing source is used to deliver a timing reference to the DNX, the state of operation is called Free Run Mode. As with the requirements of Stratum 3 clock sources, a back-up mode is available for use if all defined clock locations are lost. The back-up mode is derived from Hold Over timing, which facilitates redundancy switching and allows maintenance to be performed on the SMC-II without affecting service. External timing is provided via four source connectors on the SMC-IIA rear card. These inputs allow the DNX to use a 64 Kbps or 1.544/2.048 Mbps composite clock from a stand-alone reference.
