Juniper CTP Series User Manual

IRIG-B mode supports the following features:
•
IRIG-B transported at rates between 1 Kbps and 25.5 Kbps.
•
Configurable output level from 0 to 7.85 volts peak-to-peak based on a 50-ohm
termination.
TDC Mode
Time domain correlation (TDC) mode supports special applications in which digital data
(NRZ) needs to be closely time correlated with a timing signal (IRIG-B). In TDC mode,
the IRIG-B signal is transported on an 8-KHz audio path, and the NRZ data is transported
using RTS/DTR (NRZ input) and CTS/DSR (NRZ output). Circuitry on the Multiservice
Interface module accepts these two streams and combines them into a single digital
data stream that is carried through the IP network in one direction, while making sure
that the time relationship between the two signals is closely maintained.
Here is a list of the features of the TDC transport function:
•
IRIG-B transported at 8-KHz with 16-bit samples; that is, no companding.
•
NRZ data rates supported from 0.5 KHz to 5000 KHz in 0.5 KHz steps.
•
Embedded frame requiring no additional bandwidth.
•
Configurable IRIG-B output level from 0x to 2x.
Figure 2 on page 7 shows the cable pinouts and the data flow when the Multiservice
Interface module operates in TDC mode.
Figure 2: Cable Pinouts and Data Flow When the Multiservice Interface
Module Operates in TDC Mode
Pinouts
3
16
6
22
5
13
ST
RT
TT
RD
SD
Framer
IP network
ST
RT
TT
RD
SD
Audio input
Clock input
Data input
Pinouts
2
14
20
23
4
19
g015451
Audio
codec
NRZ
rate
adapt
Framer
Audio output
Clock output
Data output
Audio
codec
NRZ
rate
adapt
Multiservice
Interface
Module
Multiservice
Interface
Module
Adaptive Clocking Overview for CTP Bundles
The goal of adaptive clocking is to prevent buffer anomalies by adjusting the clocks so
that they are the same at each end of the network. If the clocks are not the same at each
end of the network, the data rate entering and exiting buffers will not be the same, which
causes a buffer underflow or overflow.
Adaptive clocking works by gathering information about packets arriving from the IP
network and using that information to determine whether adjustments need to be made
to the local clock to maintain frequency lock with the remote end. This process is called
adaptive time domain processing (ATDP). ATDP provides rapid convergence to the
correct clock, and does not vary due to changes in the average jitter buffer fill. As a result,
7Copyright © 2018, Juniper Networks, Inc.
Chapter 1: Overview of CTP Bundles

Juniper CTP Series Specifications

General

Brand	Juniper
Model	CTP Series
Category	Server
Language	English