MT90883 Zarlink Semiconductor, MT90883 Datasheet - Page 25

• Manufacturer Part Number: MT90883
• Description: (MT90880 - MT90883) TDM to Packet Processors
• Manufacturer: Zarlink Semiconductor

4.6
The H.100/H.110 TDM bus commonly used in today’s computer telephony systems is based on a physical
backplane the width of a single telecom rack. Extending the reach of the bus is expensive using traditional TDM
infrastructure. Such links are not easily scalable, and require accurate and stable clock generation.
An MT9088x device enables the bus to be simply and easily extended beyond confines of the rack using an
Ethernet connection over simple twisted pair cable. This enables the entire bus to be replicated in another physical
location using a low cost but flexible and easily managed connection medium (see Figure 7).
Figure 7 shows the MT9088x device connected to a TDM backplane via a TDM switch device (e.g. the Zarlink
MT90866). This is used to concentrate the backplane onto the TDM interface of the MT9088x. The configuration
allows any of the TDM channels on the original backplaneto be switched onto any channel on the extension
backplane, and vice-versa.
4.7
One of the issues faced by medium and high-end telecommunication systems is scalability. The H.100/H.110
TDM bus is limited to 4096 concurrent timeslots, or 2048 full duplex links. The MT9088x family can be used to
expand the capacity of a system by switching timeslots between multiple separate H.100/H.110 bus segments.
This application is shown in Figure 8. Unlike parts based on expensive or proprietary infrastructure, the use of
an Ethernet switch fabric enables common, readily available network hardware to be employed, reducing both
installation and operational costs.
As in Figure 7, the MT90866 TDM switch is used to concentrate the TDM backplane onto the MT9088x TDM
interface. This allows any channel on a bus segment to be switched onto any channel on any other bus
segment.
bus segment
H.100/H.110
H.100/H.110 Extension
H.100/H.110 Expansion
Original
MT90866
Switch
H.110
Figure 7 - H.100/H.110 Extension over Ethernet link
Processor
MT90880
TDM-IP
Zarlink Semiconductor Inc.
MT90880/1/2/3
transparent data flow
Ethernet
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Processor
MT90880
TDM-IP
MT90866
Switch
H.110
bus segment
H.100/H.110
Extension
Data Sheet