Polycom DOC2237A - Manual (Page 100)

Chapter 4 - Hardware Description
4-28
Net-E1/Net-T1 ISDN Network Interface Module
The Net-E1/Net-T1 ISDN Network Interface module provides the interface
between the MGC unit and the ISDN network. It supports up to two PRI
connections of the same type (E1, T1). One ISDN Network Interface module
in each MGC unit serves as the “master clock,” which synchronizes the
system clock to the ISDN network clock. The second module provides a
backup clock, which is used if the master clock fails.
Two types of Net-E1/Net-T1 ISDN Network Interface modules are available:
• The NET- T1 Network Interface Module supports channels at data rates
of Nx56/64 Kbps to 1536 Kbps. The module provides channel allocation
options as described in Table 4-6
• The NET- E1 Network Interface Module supports channels at data rates
of Nx56/64 Kbps to 1920 Kbps. The module provides channel allocation
options as described in Table 4-7.
Table 4-6: NET-T1 channel allocation
Line type Channel allocation Signaling supported
ISDN
23x56/64 Kbps
multimedia channels;
64 Kbps D-channel
signaling Variety of North American
signaling protocols
including AT&T, 4ESS,
5ESS and Northern
Telecom DMS-100 and
DMS-250
Point-to-point leased Transmission without
signaling
Table 4-7: NET-E1 channel allocation
Line type Channel allocation Signaling supported
ISDN
23x64 Kbps multimedia
channels; 64 Kbps D-
channel signaling Euro-ISDN Standard (ETSI
NET 5)
Point-to-point leased Transmission without
signaling