Polycom DOC2557A - Manual (Page 18)

Chapter 1-Hardware Description
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RTM ISDN 1500
The RTM ISDN 1500 connects directly to the built-in MPMx. The RTM
ISDN card routes data between the MPMx card and components of the
system, converts ISDN T1/E1 media to IP packets and provides
connectivity to external ISDN networks.
The RTM ISDN card is installed on the rear panel of the RMX interfaces
between the RMX unit and the ISDN/PSTN switch.
The RTM ISDN card contains four connections to which up to four E1 or
T1 PRI lines can be connected as shown in Figure 1-4.
Figure 1-4 RMX 1500 RTM ISDN Rear Panel Layout
Standby button Toggle button. Use this button to either perform
Diagnostics or Software Recovery on the RMX.
Short press (2 seconds) - MPMx Diagnostics.
Long press - (10 seconds) Media and RTM IP 1500
Software Recovery.
Table 1-5 RMX 1500 Rear Panel - RTM IP 1500 Component Description
Item Description
With the RMX 1500, you can either have a dedicated E1 or T1 Type Network
Service. It is not possible to have a mixed E1 and T1 ISDN Network Service.
4 E1/T1 connections
The RTM ISDN card supports up to 200 audio participants, regardless of
whether the spans are E1 or T1.