mt89l85apr1 Zarlink Semiconductor, mt89l85apr1 Datasheet - Page 11

• Manufacturer Part Number: mt89l85apr1
• Description: 256 X 256 Channels 8 Tdm Streams At 2.048 Mbps 3.3 V Non-blocking Enhance Digital Switch Edx With Constant Delay Mode
• Manufacturer: Zarlink Semiconductor

Low Latency Isochronous Network
In today's local working group environment, there is an increasing demand for solutions on interconnection of
desktop and telephone systems so that mixed voice, data and video services can be grouped together in a reliable
network allowing the deployment of multimedia services. Existing multimedia applications require a network with
predictable data transfer delays that can be implemented at a reasonable cost. The Low Latency Isochronous
Network is one of the alternatives that system designers have chosen to accommodate this requirement (see
Figure 8a). This network can be implemented using existing TDM transmission media devices such as ISDN Basic
(S or U) and Primary rates trunks (T1 and CEPT) to transport mixed voice and data signals in grouped time slots;
for example, 2B channels in case of ISDN S or U interfaces or up to 32 channels in case of a CEPT link.
Figure 8b shows a more detailed configuration whereby several PCs are connected to form an Isochronous
network. Several services can be interconnected within a single PC chassis through the standardized Multi Vendor
Integration Protocol (MVIP). Such an interface allows the distribution and interconnection of services like voice
mail, integrated voice response, voice recognition, LAN gateways, key systems, fax servers, video cards, etc.
The information being exchanged between cards through the MVIP interface on every computer as well as between
computers through T1 or CEPT links is, in general, of mixed type where 64 Kb/s and N*64 Kb/s channels are
grouped together. When such a mixed type of data is transferred between cards within one chassis or from one
computer to another, the sequence integrity of the concatenated channels has to be maintained. The MT89L85
device suits this application and can be used to form a complete non-blocking switch matrix of 512 channels (see
Figure 9). This allows 8 pairs of ST-BUS streams to be dedicated to the MVIP side whereas the remaining 8 pairs
are used for local ancilliary functions in typical dual T1/E1 interface applications (Figure 10).
Another application of the MT89L85 in an MVIP environment is to build an ISDN S-interface card (Figure 11). In this
card, 7 pairs of ST-BUS streams are connected to the MVIP interface while the remaining pair is reserved for the
interconnection of Zarlink MT8930 (SNIC), MT8992 (H-PHONE) and the MVIP interface.
Access to
Public
Network
T1/E1
Analog Connections
• • • • • •
Figure 8a - Private Isochronous Network
Server 3
Server 2
Zarlink Semiconductor Inc.
MT89L85
T1
Isochronous Network
11
ISDN Desktops
T1
(2B+D)
• • • • • •
E1
Server 4
Server 1
n x 64
Connections
(e.g. Video)
Data Sheet