Juniper JUNOSE 10.0.X PHYSICAL LAYER, Configuration Manual

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Unframed E1 lines have no timeslots reserved for framing. The router creates
one channel for an unframed E1 line and assigns the number one to that channel.
NOTE: To configure a whole T1 or E1 line, assign 24 T1 or 31 E1 timeslots to a
channel group or configure an unframed E1 line.
To identify a controller over SONET/SDH VT, you must consider the multiplexing for
SONET and SDH
virtual tributaries . In SONET, an STS-1 frame can be divided into
seven virtual tributary (VT) groups. Similarly, for SDH, an STM-0 frame can be divided
into seven tributary units (TUs). Each group or unit contains a number of virtual
tributaries; that number depends on the VT type or TU name. Table 11 on page 114
lists the VT types and TU names that the router supports.
Table 11: Tributary Standards That cOCx/STMx Interfaces Support
Signal Standard
Number of Tributaries
in a Group
TU Name (SDH) VT Type (SONET)
T1 4 TU-11 VT1.5
E1 3 TU-12 Not supported
Figure 9 on page 114 shows the structure for SONET, and Figure 10 on page 115 shows
the structure for SDH.
Figure 9: SONET Multiplexing
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Platform Considerations
JUNOSe 10.0.x Physical Layer Configuration Guide