Mitel MT90840 manual Distributed Isochronous Network

Preliminary Information MT90840

Applications

Distributed Isochronous Network

Low latency isochronous backbones provide for the deployment of systems that require cost effective implementation, high bandwidth, predictable data transfer delays and direct synchronization with the wide area network.

Some applications in Computer Telephony Integration (CTI) require a large amount of bandwidth to be transported between multiple chassis within the same location, or between separate locations. The MT90840 is ideal for implementing physically distributed transport and switching systems for multi-chassis or inter-shelf communications.

The MT90840 bridges existing Mitel ST-BUS components into a new networking environment where mixed data, voice and video signals can be time-interchanged or multiplexed from serial PCM streams onto serial high-speed time-division- multiplex (TDM) isochronous backbones operating at

SONET rates such as 51 (STS-1) or 155 Mbps (STS-3).

Today, transmission links operating at SONET rates utilize serial-to-parallel and parallel-to-serial converters (or framers) which perform embedded framing functions and give the user access to the payload of the high speed frame. The MT90840 provides an 8-bit bidirectional parallel data port which directly interfaces to a high-speed framer parallel data interface, allowing designers to build distributed networking systems with interconnection speeds up to 155 Mbps. Figure 16 shows an example of a distributed networking application in a CTI system.

The MT90840's clock synchronization and reference options allow many applications and topologies when isochronous TDM backbones are required. Two major clock synchronization schemes provided by the MT90840 allow the serial port interface (ST-BUS) to provide the master clock and frame reference signals for the distributed high speed backbone (master operation) or to derive the entire ST-BUS clock and frame reference signals from the high speed backbone (slave operation). This type of

CTI Server				24/30B+D
		ST-BUSMT8977/9079		PSTN
Switching	MT90810		T1 & E1 I/F
	FMIC			CTI
BUS			Call
e.g.; MVIP			Processing	SERVER
			155 Mbps
	MT90840		Framing &
			Optics	Up to 2400 TDM
				channels of user data
	ST-BUS		MT896x
			Filter/Codec
	MT90810
	FMIC		Filter/Codec
	ST-BUS	MT8930 / 71
	MT8985/6		(2B+D) I/F
	EDX	ISO Ethernet
				CTI
			MUX
				SERVER
	LAN ADAPTER CARD			Interchassis Signalling
				(e.g. Mitel’s Connection
				Master Software)

Figure 16 - CTI Distributed Architecture Implemented with the MT90840

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