Specifications

Integrator’s Reference Manual for Polycom HDX Systems
4–254 Polycom, Inc.
through 7 are inactive, but 8 is active and available, then 8 is the first channel
that can be used by the system to place an outgoing call. If an additional
channel is needed, the system will use the next available active channel in the
range (which could be 9, and so on).
Incoming Calls. For incoming calls, the system may use the highest numbered
channel in the range and, if needed, proceed to the next channel number in
descending order, depending on the type of third-party equipment attached to
the system. For example, an incoming call arrives on channel 23, then 22, 21,
and so on.
Dedicated full PRI T1 or E1 Line. All channels should be active for a full T1
or E1 line dedicated to your system.
Fractional PRI T1 or E1. Channel selection should be handled by your PRI
network administrator.
PRI E1 Channel Information. The PRI Status screen (for E1) shows 30
channels. However, E1 trunk lines have 32 timeslots, numbered 0 - 31.
Timeslot 0 is used for framing, and timeslot 16 is used for call signaling (the D
channel). The remaining 30 timeslots are used as bearer (data) channels. In call
signaling between our equipment and the switch, these channels are
numbered 1-15, 17-31. But the PRI Status screen numbers these channels
contiguously in the range 1-30. Therefore, on the PRI Status screen, channels
1-15 control the status of timeslots 1-15, and channels 16-30 control the status
of timeslots 17-31.