Juniper CTP Series User manual

CTP Series Circuit to Packet Platform
Using Bundles to Create Logical Configurations for
Physical Interfaces
Release
7.3
Modified: 2018-01-29
Copyright © 2018, Juniper Networks, Inc.

Juniper Networks, Inc.
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Sunnyvale, California 94089
USA
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www.juniper.net
Copyright © 2018 Juniper Networks, Inc. All rights reserved.
Juniper Networks, the Juniper Networks logo, Juniper, and Junos are registered trademarks of Juniper Networks, Inc. and/or its affiliates in
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Juniper Networks assumes no responsibility for any inaccuracies in this document. Juniper Networks reserves the right to change, modify,
transfer, or otherwise revise this publication without notice.
Using Bundles to Create Logical Configurations for Physical Interfaces, CTP Release 7.3, CTPView Release 7.3
Copyright © 2018 Juniper Networks, Inc. All rights reserved.
Revision History
January 2018—CTP Software Configuration Guide, CTP Release 7.3, CTPView Release 7.3
The information in this document is current as of the date on the title page.
END USER LICENSE AGREEMENT
The Juniper Networks product that is the subject of this technical documentation consists of (or is intended for use with) Juniper Networks
software. Use of such software is subject to the terms and conditions of the End User License Agreement (“EULA”) posted at
http://www.juniper.net/support/eula/. By downloading, installing or using such software, you agree to the terms and conditions of that
EULA.
Copyright © 2018, Juniper Networks, Inc.ii

Table of Contents
Part 1 Overview
Chapter1 OverviewofCTPBundles...........................................3
TypesofBundlesOverview............................................3
Interface Naming Conventions for the CTP Series . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Serial Multiservice Interface Module Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
AudioMode.....................................................5
4WTOMode....................................................6
IRIGMode......................................................6
TDCMode......................................................7
Adaptive Clocking Overview for CTP Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Determining Optimal Packet Size for CTP Bundles Overview . . . . . . . . . . . . . . . . . 8
Bandwidth for Transporting Serial Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
PacketCreationDelay.............................................9
PerformanceoftheIPNetwork.....................................9
Providing QoS for CTP Bundles by Using Service Type Overview . . . . . . . . . . . . . . 10
CircuitStartupProcessOverview.......................................11
TransparentEncodingOverview........................................12
Transparent Encoding Applications and Support Overview . . . . . . . . . . . . . . 12
How Basic Transparent Encoding Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Using Phase-Correction FIFO Buffer with Transparent Encoding . . . . . . . . . . 14
Using Send Timing (ST) Clocking for Higher Speed Circuits with Transparent
Encoding...................................................16
TDM/TDCEncodingOverview.........................................17
HowTDMInterleavingWorks......................................17
How the CTP Implementation of TDM/TDC Works . . . . . . . . . . . . . . . . . . . . . 18
TDMRates.....................................................19
TDM High-Speed and Low-Speed Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Chapter2 ConfiguringCTPBundles...........................................23
AddingaBundle(CTPView)..........................................24
AddingaBundle(CTPMenu).........................................25
Configuring IP Parameters for CTP Bundles (CTPView) . . . . . . . . . . . . . . . . . . . . 25
Configuring IP Parameters for CTP Bundles (CTP Menu) . . . . . . . . . . . . . . . . . . . . 27
Configuring Circuit Startup Parameters for CTP Bundles (CTPView) . . . . . . . . . . 29
Configuring Circuit Startup Parameters for CTP Bundles (CTP Menu) . . . . . . . . . 30
Configuring the CTP Bundle Data Packet Protocol and OAM Port (CTP
Menu).........................................................31
Ethernet Media Configuration Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Support for Full-Duplex Mode Only on NIC Ports Connected to CTP
Devices....................................................33
iiiCopyright © 2018, Juniper Networks, Inc.

Displaying Ethernet Media Information (CTP Menu) . . . . . . . . . . . . . . . . . . . . . . . 33
Configuring Ethernet Media (CTP Menu) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Configuring the Direction of the Circuit (CTPView) . . . . . . . . . . . . . . . . . . . . . . . . 35
Configuring the Direction of the Circuit (CTP Menu) . . . . . . . . . . . . . . . . . . . . . . . 36
Configuring Virtual IP Parameters for CTP Bundles (CTPView) . . . . . . . . . . . . . . . 37
Configuring Virtual IP Parameters for CTP Bundles (CTP Menu) . . . . . . . . . . . . . 38
Configuring the Missing Packet Fill Pattern for CTP Bundles (CTPView) . . . . . . . 39
Configuring the Missing Packet Fill Pattern for CTP Bundles (CTP Menu) . . . . . . 40
Configuring IP Forwarding for CTP Bundles (CTPView) . . . . . . . . . . . . . . . . . . . . . 41
Configuring IP Forwarding for CTP Bundles (CTP Menu) . . . . . . . . . . . . . . . . . . . . 42
Configuring Signaling for CTP Bundles (CTPView) . . . . . . . . . . . . . . . . . . . . . . . . 44
Configuring Signaling for CTP Bundles (CTP Menu) . . . . . . . . . . . . . . . . . . . . . . . 48
Configuring Serial Port Parameters for CTP Bundles (CTPView) . . . . . . . . . . . . . 52
Configuring Serial Port Parameters for CTP Bundles (CTP Menu) . . . . . . . . . . . . 54
Configuring Transparent Encoding for CTP Bundles (CTPView) . . . . . . . . . . . . . . 58
Configuring Transparent Encoding for CTP Bundles (CTP Menu) . . . . . . . . . . . . . 60
Configuring Bundle Pairs for TDM/TDC Operation (CTPView) . . . . . . . . . . . . . . . 62
Configuring the High-Speed CTP Bundle for TDM/TDC Operation
(CTPView) .................................................62
Configuring the Low-Speed CTP Bundle for TDM/TDC Operation
(CTPView) .................................................63
Configuring Bundle Pairs for TDM/TDC Operation (CTP Menu) . . . . . . . . . . . . . . 64
Configuring the High-Speed CTP Bundle for TDM/TDC Operation (CTP
Menu).....................................................64
Configuring the Low-Speed CTP Bundle for TDM/TDC Operation (CTP
Menu) ....................................................66
Configuring T1 and E1 Port Parameters for CTP Bundles (CTPView) . . . . . . . . . . 66
Configuring T1 and E1 Port Parameters for CTP Bundles (CTP Menu) . . . . . . . . . 69
Configuring Multiservice Port Parameters for CTP Bundles (CTPView) . . . . . . . . 72
Configuring Multiservice Audio Mode Port Parameters for CTP Bundles
(CTPView) .................................................72
Configuring Multiservice IRIG-B Mode Port Parameters for CTP Bundles
(CTPView) .................................................74
Configuring Multiservice TDC Mode Parameters for CTP Bundles
(CTPView) .................................................76
Configuring Multiservice 4WTO Mode Port Parameters for CTP Bundles
(CTPView) .................................................77
Configuring Multiservice Port Parameters for CTP Bundles (CTP Menu) . . . . . . . 78
Configuring Multiservice Audio Mode Port Parameters for CTP Bundles (CTP
Menu).....................................................79
Configuring Multiservice IRIG-B Mode Port Parameters for CTP Bundles
(CTPMenu)................................................81
Configuring Multiservice TDC Mode Parameters for CTP Bundles (CTP
Menu).....................................................83
Configuring Multiservice 4WTO Mode Port Parameters for CTP Bundles
(CTPMenu)................................................84
Configuring 4WTO Port Parameters for CTP Bundles (CTPView) . . . . . . . . . . . . 86
Configuring 4WTO Port Parameters for CTP Bundles (CTP Menu) . . . . . . . . . . . 89
Configuring IRIG-B Port Parameters for CTP Bundles (CTPView) . . . . . . . . . . . . . 92
Copyright © 2018, Juniper Networks, Inc.iv
Using Bundles to Create Logical Configurations for Physical Interfaces, CTP Release 7.3, CTPView Release 7.3

Configuring IRIG-B Port Parameters for CTP Bundles (CTP Menu) . . . . . . . . . . . . 94
Configuring Advanced Port Options for CTP Bundles (CTPView) . . . . . . . . . . . . . 96
Configuring Advanced Port Options for CTP Bundles (CTP Menu) . . . . . . . . . . . . 97
Configuring Port Mirroring for CTP Bundles (CTPView) . . . . . . . . . . . . . . . . . . . . . 99
Configuring Port Mirroring for CTP Bundles (CTP Menu) . . . . . . . . . . . . . . . . . . . 100
Configuring Cryptographic Resynchronization (Crypto Resync) . . . . . . . . . . . . . . 102
Gathering Node Debugging Information (CTP Menu) . . . . . . . . . . . . . . . . . . . . . 103
Selecting the Type of Clocking on Serial Ports for CTP Bundles (CTPView) . . . . 104
Selecting the Type of Clocking on Serial Ports for CTP Bundles (CTP Menu) . . . 106
Configuring Custom Clocking for CTP Bundles (CTPView) . . . . . . . . . . . . . . . . . 109
Configuring Custom Clocking for CTP Bundles (CTP Menu) . . . . . . . . . . . . . . . . . 112
Configuring Adaptive Clocking for CTP Bundles (CTPView) . . . . . . . . . . . . . . . . . 115
Configuring Adaptive Clocking for CTP Bundles (CTP Menu) . . . . . . . . . . . . . . . . 117
NetworkNodeReferenceOverview....................................118
GuidelinesforConfiguringNetRef..................................119
Configuring NetRef for Adaptive Bundle Operation . . . . . . . . . . . . . . . . . . . . . . . 120
Configuring NetRef for Primary or Backup Operation . . . . . . . . . . . . . . . . . . . . . . . 121
Support for Multiple Master Nodes to Associate With a Single Slave Node in
NetRef........................................................121
Configuring NetRef Multiple Master Nodes (CTP Menu) . . . . . . . . . . . . . . . . . . . 124
Configuring NetRef Settings (CTPView) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Loss of Signal Detection Capability on CTP Bundles and SAToP Bundles . . . . . . 129
Detection of LOS on Serial Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Detection of LOS on T1/E1 Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Guidelines for Configuring LOS Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Configuring LOS Detection on CTP and SAToP Bundles (CTP Menu) . . . . . . . . . 133
Part 2 Administration
Chapter 3 Activating, Disabling, Deleting, or Recentering CTP Bundles . . . . . . . . . . . 137
Activating, Disabling, Deleting, or Recentering CTP Bundles (CTPView) . . . . . . . 137
Activating, Disabling, Deleting, or Recentering for CTP Bundles (CTP Menu) . . . 137
Chapter4 QueryingCTPBundles............................................139
Displaying Running CTP Bundle Configuration, State, and Counters
(CTPView)....................................................139
Displaying the NetRef Node Synchronization Information (CTP Menu) . . . . . . . 143
Displaying the Running CTP Bundle Configuration, State, and Counters (CTP
Menu)........................................................145
Chapter 5 Monitoring Packet Creation and Reception and Packet Delay for CTP
Bundles .........................................................153
Using SCC Counts to Monitor Packet Creation and Reception for CTP Bundles
(CTPMenu)...................................................153
Using Buffer Sampling to Monitor Packet Delay for CTP Bundles (CTP
Menu)........................................................154
vCopyright © 2018, Juniper Networks, Inc.
Table of Contents

Chapter 6 Diagnostic Testing for CTP Bundles Overview . . . . . . . . . . . . . . . . . . . . . . . . 157
Serial Loops for CTP Bundles Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Normal Data Flow in the CTP Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
SerialLooptotheSerialInterface..................................157
SerialLooptotheNetwork.......................................158
BERT Testing for CTP Bundles Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
End-to-End BERT for CTP Bundles Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Chapter 7 Configuring Diagnostic Testing for CTP Bundles . . . . . . . . . . . . . . . . . . . . . . 161
Configuring Serial Loops for CTP Bundles (CTPView) . . . . . . . . . . . . . . . . . . . . . . 161
Configuring Serial Loops for CTP Bundles (CTP Menu) . . . . . . . . . . . . . . . . . . . . 162
Configuring BERT Testing for CTP Bundles (CTPView) . . . . . . . . . . . . . . . . . . . . 163
Configuring BERT Testing for CTP Bundles (CTP Menu) . . . . . . . . . . . . . . . . . . . 165
Chapter 8 Displaying BERT Status and Counters for CTP Bundles . . . . . . . . . . . . . . . . 167
Displaying BERT Status and Counters for CTP Bundles (CTPView) . . . . . . . . . . 167
Displaying BERT Status and Counters for CTP Bundles (CTP Menu) . . . . . . . . . 168
Chapter 9 Reducing the Number of SNMP Traps Generated for Late and Missing
Packets..........................................................171
Reducing the Number of SNMP Traps Generated for Late and Missing Packets
(CTP Menu) ...................................................171
Copyright © 2018, Juniper Networks, Inc.vi
Using Bundles to Create Logical Configurations for Physical Interfaces, CTP Release 7.3, CTPView Release 7.3

PART 1
Overview
•Overview of CTP Bundles on page 3
1Copyright © 2018, Juniper Networks, Inc.

Copyright © 2018, Juniper Networks, Inc.2
Using Bundles to Create Logical Configurations for Physical Interfaces, CTP Release 7.3, CTPView Release 7.3

CHAPTER 1
Overview of CTP Bundles
•Types of Bundles Overview on page 3
•Interface Naming Conventions for the CTP Series on page 4
•Serial Multiservice Interface Module Overview on page 5
•Adaptive Clocking Overview for CTP Bundles on page 7
•Determining Optimal Packet Size for CTP Bundles Overview on page 8
•Providing QoS for CTP Bundles by Using Service Type Overview on page 10
•Circuit Startup Process Overview on page 11
•Transparent Encoding Overview on page 12
•TDM/TDC Encoding Overview on page 17
Types of Bundles Overview
Table 1 on page 3 shows the typical application for each bundle type, and lists the
interfaces that each type of bundle supports.
Table 1: Bundle Types and Supported Interfaces
Interface Types SupportedGenerally Used ForBundle Type
•CTP150
•Serial interface
•Multiservices interface
•T1/E1 interface
•CTP2000
•Multiservices interface
•Serial interface
•Serial interface with T1/E1 daughter
card
•Serial interface with 4WTO
daughter card
•Serial interface with IRIG-B
daughter card
•T1/E1 interface
Connecting legacy serial interfaces to
the IP network
CTP (circuit-to-packet)
3Copyright © 2018, Juniper Networks, Inc.

Table 1: Bundle Types and Supported Interfaces (continued)
Interface Types SupportedGenerally Used ForBundle Type
•CTP150
•T1/E1 interface
•CTP2000
•Serial interface with T1/E1 daughter
card
•T1/E1 interface
Connecting single T1 or E1 interfaces to
an IP network
SAToP (structure-agnostic TDM over IP)
•CTP2000
•T1/E1 interface with unused DS0s
•FXS interface
•FXO interface
•4W-E&M interface
•CTP150
•T1/E1 interface with unused DS0s
•Serial interface
An unused DS0 is a DS0 not assigned to
another bundle. When a CESoPSN
bundle is attached to a port, by default
all unused DS0s are assigned to the
bundle.
Grouping multiple DS0s to one IP circuitCESoPSN (circuit emulation services
over a packet-switched network)
•CTP2000
•T1/E1 interface
•4W-E&M interface
•Voice compression module
•FXS interface
•FXO interface
Grouping multiple analog circuits
(channels) into one IP circuit
VComp (voice compression)
Interface Naming Conventions for the CTP Series
In the CTP software, interfaces are specified in the format:
type-slot/port
where
type—Type of interface. A two-character abbreviation.
slot—Slot number on the CTP device.
port—Port number on the CTP device.
If the interface module has a daughter card installed, the interface format is as follows:
type-slot/port w/daughter-card
Copyright © 2018, Juniper Networks, Inc.4
Using Bundles to Create Logical Configurations for Physical Interfaces, CTP Release 7.3, CTPView Release 7.3

Table 2: Interface Type Specifiers
Type SpecifierInterface Type
4w4WE&M
4w4WTO
e1E1
fo2W-FXO
fs2W-FSX
irigIRIG
seSerial
t1T1
t1e1T1E1
Serial Multiservice Interface Module Overview
CTP bundles are supported on the Serial Multiservice Interface module. CTP bundles on
Multiservice Interface modules can operate with the following modes:
•Audio—Provides single and dual channel audio support for varying quality audio from
8-bit, 8-KHz quality to 8-bit up to 16-bit, 48-KHz quality (CD quality).
•4WTO—Provides single and dual channel audio support for 8-bit, 8-KHz quality with
squelch support for radio backhaul. In 4WTO mode, the Multiservice Interface module
is interoperable with 4WTO daughter cards.
•IRIG—Enables an interrange instrumentation group time code (IRIG-B) signal to be
transported through an IP network.
•TDC—Provides combined time-correlated support for IRIG/NRZ data for telemetry
applications.
Audio Mode
Audio mode provides a high-quality audio (CD quality) interface. Audio mode supports
the following features:
•One or two simultaneous channels.
•Codec sampling rates up to 48 KHz.
•Optional μ-law encoding and decoding.
•Embedded frame requiring no additional bandwidth.
5Copyright © 2018, Juniper Networks, Inc.
Chapter 1: Overview of CTP Bundles

•Configurable output level from 0x to 2x.
•Signaling capability with talk squelch.
Figure 1 on page 6 shows the cable pinouts and the data flow when the Multiservice
Interface module operates in audio mode.
Figure 1: Cable Pinouts and Data Flow When the Multiservice Interface
Module Operates in Audio Mode
Framer IP network
ST - 12.288 MHz
RT - 32.768 MHz
TT
RD
SD
Dual channel only
Audio input
Squelch input
Audio codec
Audio output
Pinouts
2
14
3
16
20
23
g015450
Audio input
Squelch input
Audio codec
Audio output
Pinouts
24
11
17
9
4
19
Multiservice
Interface
Module
4WTO Mode
The CTP 4-wire trunk only (4WTO) analog option provides encoding for one or two
analog voice channels into a single CTP IP data stream.
4WTO mode supports the following features:
•One or two simultaneous channels.
•Codec sampling rate of 8 KHz.
•Optional μ-law encoding.
•Signaling capability with talk squelch.
•Configurable output level from 0x to 2x.
•Interoperability with a 4WTO daughter card. Interoperability is supported only on
daughter cards that have firmware revision 4 or later. You enable interoperability in
the 4WTO daughter card configuration by setting MS interwork to enabled.
IRIG Mode
The Multiservice Interface module enables an interrange instrumentation group time
code (IRIG-B) signal to be transported through an IP network. The IRIG-B standard
consists of a family of rate-scaled serial time codes with formats containing up to three
coded expressions or words. The IRIG-B pulse code contains one frame of 100 elements
per second for the time of the year and GPS receiver status. IRIG-B encodes day of year,
hour, minute, and second data on a 1-KHz carrier frequency, with an update rate of once
per second.
Copyright © 2018, Juniper Networks, Inc.6
Using Bundles to Create Logical Configurations for Physical Interfaces, CTP Release 7.3, CTPView Release 7.3

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

a circuit continuously operates without a buffer recenter, even when clock references
are not used.
There are two types of adaptive clocking:
•Adaptive clocking with internal clock—Recovers the clock from the user equipment
connected to the remote CTP device and uses it to generate both transmit and receive
timing. All clocking is performed by the DDS, which is initially configured to be locked
to the local system clock. When packets begin to flow between the CTP devices, the
adaptive clock begins time domain analysis of the packets that arrive from the remote
CTP device. Based on this analysis, adjustments are made to the DDS clock to
approximate the frequency of the clock used to create network-bound packets on the
remote CTP. In this way, the local CTP port can maintain long-term frequency lock
with the remote CTP and pass this clock to the locally connected user equipment.
•Adaptive clocking with external TX clock—Data received from the local user equipment
that is bound to the IP network is clocked using the CTP external user clock (the transmit
timing clock). Data received from the remote CTP device and bound for the interface
is adaptively clocked with the recovered clock from the user equipment connected to
the remote CTP device. This configuration allows for independent adaptive configuration
in each direction. With this method, the user equipment can send packets into the
network with their local clock, and the remote end CTP devices adaptively recover this
clock. This clocking method is useful when the port speed is high or the cable length
between the user equipment and CTP device is large.
Related
Documentation
Configuring Adaptive Clocking for CTP Bundles (CTP Menu) on page 117•
•Configuring Adaptive Clocking for CTP Bundles (CTPView) on page 115
Determining Optimal Packet Size for CTP Bundles Overview
You can specify the size of IP packets that are created from data received at the serial
port. The CTP device uses packet size along with the serial interface rate to calculate
the packet rate; that is, the rate that packets are created. The maximum packet rate is
1500 packets per second.
To determine the optimal packet size, consider the following:
•Bandwidth for transporting serial data
•Packet creation delay
•Performance of the IP network
For example, larger packet sizes are more bandwidth-efficient, but introduce more delay
during packet creation.
Bandwidth for Transporting Serial Data
When considering bandwidth in relation to deciding packet size, add overhead for both
the Layer 2 encapsulation and the IP header. The IP header comprises 20 bytes; and the
Copyright © 2018, Juniper Networks, Inc.8
Using Bundles to Create Logical Configurations for Physical Interfaces, CTP Release 7.3, CTPView Release 7.3

encapsulation overhead varies, but is typically either 6 or 8 bytes on serial links. This
overhead causes smaller packets to be less efficient and result in serial data requiring
more bandwidth.
Calculate the bandwidth required for a serial bit stream as follows:
IP Bandwidth = [Packet Size (bytes) + 20 (bytes) + 2 (bytes) + Encapsulation
Overhead (bytes) x [Packet Rate (pps)] x 8
Packet Creation Delay
Serial data received at the CTP interface must be buffered long enough to allow a packet
to be created. The delay to create the packet increases as either the size of the packet
increases or as the rate of the serial interface decreases. Generally, this delay is minimal
except when the rate of the serial interface is low and the packet size is large. We
recommend that you set the packet size to a smaller value for lower-speed serial
interfaces. Table 3 on page 9 provides examples of serial interface packet creation delay
in milliseconds.
Table 3: Packet Creation Delay for Serial Interfaces
Serial Interface Delay (msec)
Packet Size (bytes)
14001024768512256128
Interface Rate
(Kbps)
175.0128.096.064.032.016.064
87/564.048.032.016.08.0128
43.832.024.016.08.04.0256
10.98.06.04.02.01.01024
7.35.34.02.71.30.71544
5.54.03.02.01.0.52048
Performance of the IP Network
The number of packets created (packet rate) is inversely related to the packet size
configured. For example, smaller packets result in a greater packet rate. When you
configure the packet size, consider the packet-forwarding performance of the attached
router and network. Table 4 on page 10 provides examples of packet rates for various
packet sizes and serial interface rates.
9Copyright © 2018, Juniper Networks, Inc.
Chapter 1: Overview of CTP Bundles

Table 4: Packet Rate for Various Packet Size and Serial Interface Rate Settings
Packet Rate (Packets per Second)
Packet Size (Bytes)
14001024768512256128
Interface Rate
(Kbps)
5.77.810.415.631.362.564
11.415.620.831.362.5125.0128
22.931.341.762.5125.020.0256
91.4125.0166.7250.0500.01000.01024
137.9188.5251.3277.0753.91507.81544
182.9250.0333.3500.01000.02000.02048
Related
Documentation
Configuring IP Parameters for CTP Bundles (CTP Menu) on page 27•
•Configuring IP Parameters for CTP Bundles (CTPView) on page 25
Providing QoS for CTP Bundles by Using Service Type Overview
In IP networks, the IP flow is typically classified based on the Differentiated Services
Code Point (DSCP) setting in the type of service (TOS) byte of the IP header. DSCP is a
scalable solution for classifying flows in a large IP network based on the class of service
desired on specific IP traffic flows.
With the CTP device, you can configure DSCP settings for each circuit’s IP flow. For
example, some circuits could be configured for the expedited forwarding (EF) class.
When the network routers receive this EF-marked flow from the CTP device, they place
the marked traffic into a high-priority queue, enabling this traffic to be serviced before
lower priority traffic. As an EF-marked flow traverses the IP network, routers can use its
classification to provide the flow a more predictable level of performance across the
network
When you configure the service type of a bundle, you specify the ToS byte to be used in
IP headers of packets sent from the CTP device to the IP network. The ToS setting is
applied to circuits created by the bundle for which the service type is configured.
Table 5 on page 10 shows the mapping for each DSCP class and setting to the ToS setting
that you configure as the service type for a bundle. The EF class (ToS setting 184) is
commonly used for circuit traffic.
Table 5: DSCP Classes and Service Type
ToS SettingDSCP SettingDSCP Class
22456CS7
Copyright © 2018, Juniper Networks, Inc.10
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Table 5: DSCP Classes and Service Type (continued)
ToS SettingDSCP SettingDSCP Class
19248CS6
18446EF
16040CS5
15238AF43
14436AF42
13634AF41
12832CS4
12030AF33
11228AF32
10426AF31
9624CS3
8822AF23
8020AF22
7218AF21
6416CS2
5213AF13
4812AF12
4010AF11
328CS1
Related
Documentation
Configuring IP Parameters for CTP Bundles (CTPView) on page 25•
•Configuring IP Parameters for CTP Bundles (CTP Menu) on page 27
Circuit Startup Process Overview
CTP devices use UDP operational and maintenance (OAM) packets to initially discover
the circuit on the remote CTP device, and to verify continued connectivity with the remote
11Copyright © 2018, Juniper Networks, Inc.
Chapter 1: Overview of CTP Bundles

device. When a bundle is activated, the CTP device sends OAM packets to the remote
circuit until the required number of packets is received. The circuit then changes its state
to in-sync, and begins sending data packets.
Circuits continue to send OAM packets to the remote device at a configured rate. If the
number of OAM packets that the CTP devices misses reaches a configured number, the
state of the circuit changes from in synchronization to no synchronization.
You can also specify how many consecutive packets the IP network must drop before
the CTP device restarts the circuit. After the circuit restarts, the CTP device must receive
a specified number of in-sequence packets before it transitions the circuit from in-sync
to running.
Related
Documentation
Configuring Circuit Startup Parameters for CTP Bundles (CTPView) on page 29•
•Configuring Circuit Startup Parameters for CTP Bundles (CTP Menu) on page 30
Transparent Encoding Overview
•Transparent Encoding Applications and Support Overview on page 12
•How Basic Transparent Encoding Works on page 13
•Using Phase-Correction FIFO Buffer with Transparent Encoding on page 14
•Using Send Timing (ST) Clocking for Higher Speed Circuits with Transparent
Encoding on page 16
Transparent Encoding Applications and Support Overview
Transparent mode is for unique applications that require the data and clock signals to
be sampled at one end of a circuit and replicated at the far end. For example, applications
in which:
•Data rates are low (32 Kbps or less) and rates can vary over time. The sampling jitter
prevents use of higher data rates.
•Data rates are low and fixed and/or low network latency is required.
•Clocks must disappear (transitions stop) periodically during circuit operation.
The transparent encoding scheme is supported only when you have worked with the
Juniper Networks Technical Assistance Center (JTAC) to verify that your application
requires this encoding scheme. You may need to use special adapters on the cable to
properly map the data and clock signals to the connector pins that the application uses.
We recommend that you do not use transparent encoding in WAN environments because
of its large consumption of bandwidth.
See Also How Basic Transparent Encoding Works on page 13•
•Using Phase-Correction FIFO Buffer with Transparent Encoding on page 14
Copyright © 2018, Juniper Networks, Inc.12
Using Bundles to Create Logical Configurations for Physical Interfaces, CTP Release 7.3, CTPView Release 7.3

•Using Send Timing (ST) Clocking for Higher Speed Circuits with Transparent Encoding
on page 16
•Configuring Transparent Encoding for CTP Bundles (CTP Menu) on page 60
•Configuring Transparent Encoding for CTP Bundles (CTPView) on page 58
How Basic Transparent Encoding Works
There are two modes of transparent encoding. They are Transparent 4 mode (TRANS)
and Transparent 8 mode (TRANS8). Transparent 8 mode is supported only on CTPOS
release 6.4 and later.
Transparent encoding mode 4 samples incoming data on four input signals (SD, TT, RTS,
and DTR), transports these signals across the IP network to the remote end of the circuit,
and sends the signals on four output signals (RD, RT, CTS, and DSR). Figure 3 on page 13
shows a simplified model of a transparent encoded circuit.
Figure 3: Simplified Model of a Transparent Encoded Circuit
IP Network
g015401
RD
RT
CTS
DSR
2
24
4
20
SD
TT
RTS
DTR
3
17
5
6
2
24
4
20
SD
TT
RTS
DTR
3
17
5
6
RD
RT
CTS
DSR
Transparent Circuit
Transparent Circuit
Pin Pin
The signal sampling rate is based on the configured port rate. For example, if the port
rate is 128 Kbps, then the four signals are sampled at 128 KHz, which generates a packet
flow through the IP network of 512 Kbps (4 x 128 KHz). The smallest sampling rate
available is 5.3 μsec (approximately 192 KHz).
To prevent errors in transport, both ends of the circuit must be synchronized with each
other. You can achieve synchronization either by locking each CTP node to a common
reference or by enabling adaptive clocking on one end of the circuit.
Transparent 8 encoding is an extension of Transparent 4 encoding. Compared with
Transparent 4 encoding, which sends four signals in each direction, Transparent 8
encoding doubles the bandwidth and allows eight signals to be sampled and transported.
This allows signals to be sent from additional interfaces that were not supported in
Transparent 4 encoding, although the bandwidth usage will be higher.
13Copyright © 2018, Juniper Networks, Inc.
Chapter 1: Overview of CTP Bundles

See Also Transparent Encoding Applications and Support Overview on page 12•
•Using Phase-Correction FIFO Buffer with Transparent Encoding on page 14
•Using Send Timing (ST) Clocking for Higher Speed Circuits with Transparent Encoding
on page 16
•Configuring Transparent Encoding for CTP Bundles (CTP Menu) on page 60
•Configuring Transparent Encoding for CTP Bundles (CTPView) on page 58
Using Phase-Correction FIFO Buffer with Transparent Encoding
The transparent encoding feature provides a phase-correction FIFO buffer. This FIFO
buffer aligns the clock and data phase relationship on a transparent encoded circuit in
which the clock travels in one direction through the network, and the data travels in the
opposite direction. The transparent FIFO buffer is needed because of the latency of signal
transport over the IP network.
Figure 4 on page 14 shows the phase-correction FIFO buffers. You can enable the
phase-correction FIFO buffer at either end of the circuit. You would not enable the FIFO
buffer at both ends of the circuit.
Figure 4: Transparent Encoding with Phase-Correction FIFO Buffers
Transparent Circuit
Transparent Circuit
DTE DCE
g015406
RD
RT
CTS
DSR
2
24
4
20
SD
TT
RTS
DTR
3
17
5
6
2
24
4
20
SD
TT
RTS
DTR
3
17
5
6
RD
RT
CTS
DSR
Pin Pin
FIFO FIFO
Figure 5 on page 15 shows the paths of the clock and data through the phase-correction
FIFO buffer that is enabled on the transparent circuit on the right.
•The clock enters the network from the DCE, goes to the DTE, and then clocks data into
the network on the DTE. The clock is also looped back on the DTE to enter the network
in phase with the data as it travels from the DTE to the DCE.
•The data enters the FIFO buffer in phase with the clock passing through the network
from the DTE to the DCE, while data is clocked out of the FIFO buffer with the clock
that entered the network from the DCE, which is in phase with the user clock.
Copyright © 2018, Juniper Networks, Inc.14
Using Bundles to Create Logical Configurations for Physical Interfaces, CTP Release 7.3, CTPView Release 7.3