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Chapter 1: Introduction to the EIU 25
The frame transport bus
Note: Because the interconnecting
Inter-message switch links required with LPP
For this reason, there is a pair of IMLs in integrated service node (ISN) switches. These IMLs are DS512 links that operate at 1024 Kbit/s. Other improvements to the MS hardware are also required to conform with the ISN maintenance strategies.
Data communications interface architecture
The overall architecture of the data communications subsystem is based partially on the premise that the processing and the access method for these entities must be separate.
For this reason, application processors (AP) have the intelligence to drive the link protocols. This arrangement allows freedom to change access methods and allows flexibility in satisfying the processing requirements for each protocol. The emphasis is on providing locally attached, nonswitched connections primarily for OAM interfaces. An example of the overall data flow for the data communications environment is shown in figure 2.