Table of Contents - Noodlez.org Courses PDF...The uppermost Linkway serves as the designated Master...

Table of Contents

Tab 1 Satellite Overview 1

Tab 2 Linkway™ Overview 13

Tab 3 Linkway™ Principles of Operations 29

Tab 4 TDMA Network Configuration 39

Tab 5 Configuration 57

Tab 6 Generating Boot Files 83

Tab 7 Troubleshooting and Maintenance 111

Tab 8 Adding a Control Group 115

TAB

Insert Tab # 1 Here

Satellite Overview

3

JNN Network

• Access Types– TDMA

– FDMA

• Terminal Types– Division Hub Node

– JNN

– CPN

The JNN network architecture currently utilizes contracted, civilian satellite bandwidth to provide long haul connectivity. This bandwidth is in the Ku- and Ka-bands, and multiple users can access via FDMA (Frequency Division Multiple Access) or TDMA (Time Division Multiple Access). In the JNN network, the links between JNNs and the Division Hub Node are both FDMA and TDMA, since JNNs typically support brigade level or higher commands. The links between CPNs and JNNs are usually TDMA based, since less bandwidth is required for the battalion-level commands the CPNs support. A CPN will rarely be connected “directly” to the Division Hub Node. Instead, its traffic will route through a JNN, and then the Division Hub Node if necessary. By creating a satellite network this way results in a more efficient allocation of bandwidth, with more bandwidth going to those units and commands that are expected to require more.

4

JNN Network

Above is an example of a simple JNN network, tied together with satellite connectivity. The example network illustrates that while the JNN network is a relatively simple, tactical network, it can provide access to the Defense Information Services Network (DISN) and Global Information Grid (GIG) through the use of long-haul satellite communications links and fixed-site, tactical teleports.

5

JNN Network

• Why satellite?– Beyond Line of Sight (BLOS) Extension

– Comparatively Simple

– Highly Mobile

– Easily Accessible

– Very Scalable

Prior to the wide-scale adoption of satellite communications, terminals from the Mobile Subscriber Equipment (MSE) generation typically were connected via Line-of-Sight (LOS). While providing high capacity throughput cheaply, there were several immediate disadvantages to LOS, particularly in a battlefield scenario. First, LOS is just that: Line of Sight. If, for example, the distant-end terminal is on the other side of a mountain or group of buildings, they will not be able to receive the transmitting LOS’ signal. Additionally, LOS systems required hefty computing resources to develop a “profile” at each end. This “profile” must be planned each time an LOS jumps. Satellite communications, on the other hand, require only initial link planning. Furthermore, each time an LOS is set up, there is a significant investment in time and manpower as the antenna and masts are installed and oriented. Satellite terminals have the advantage, in that they are quick to deploy and breakdown. In the current generation of satellite communication terminals, most antennas are automatically deployable, further increasing the ease with which terminals can access, or de-access the satellite network.

6

Satellite Ground Segment

• All Terminals Transmitting to Satellite– Antenna

– Feed Systems

– Amplifiers

– Modems and Converters

– Power Distribution

All satellite communications terminals share some common features and components. The first of these is the antenna, more commonly referred to as the dish. The antenna is the point at which the RF signal enters and exits the terminal. The antenna used in satellite communications is a configuration referred to as parabolic. The unique shape of a parabolic antenna allows the relatively weak signal coming from the satellite to be collected and focused into a single point prior to entering the terminal’s communication system. The second common feature of satellite communications terminals is the feed system. The feed system of a satellite communications system is responsible for preparing, or “conditioning” the signal for processing within the terminal. The feed system consists of devices such as polarizers, duplexers, and orthomode transducers. The feed system also serves as a kind of filter for the RF signal, since ALL RF frequencies that the terminal can “see” are being absorbed by the antenna. The feed system ensures that the correct signal is being processed. The third system component common to all terminals is the amplifier. On the receive side, the amplifier is a LNA, or Low Noise Amplifier. This component takes the relatively weak signal coming from the satellite and boosts its power within the terminal, while adding a minimum of noise. On the transmit side, the component is a High-Powered Amplifier, or HPA, which boosts the power level of the signal before it leaves the terminal. This power boost is necessary to ensure

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the signal both reaches the satellite in space, and has enough power for the return trip back to the Earth. Though there are variations on these components, (such as an MPA, or Medium Power Amplifier), the basic concepts remain the same. Next are the modems and converters. Modems both modulate and demodulate the signal (The word modem is actually a portmanteau of “modulate” and “demodulate”), depending on whether the signal is being transmitted or received. Modulation is the process of adding information to the signal prior to transmit, and demodulation is the process of extracting that information after reception. Converters changed the signal’s frequency from an external (radio frequency, or RF) frequency, to an internal frequency (IF), or vice versa. While at one time these were separate components, most modern satellite communications systems incorporate frequency conversion into their modems. Finally, all satellite communications terminals require some form of power distribution. Like any electronic system, a satellite communication terminal requires power to run. This power can be provided from any number of sources, with tactical, flyaway terminals needing only small generators, and large, fixed-site systems tied to the civilian power grid.

8

Satellite Space Segment (1)

• Major Components of a Satellite– Communications Payload

• Antennas

• Repeater/s

– Spacecraft Bus• Telemetry, Tracking & Control (TT&C)

• Electrical Power

• Propulsion and Attitude Control

• Thermal Control

A satellite consists of two groups of components, the communications payload, and the satellite bus. The communications payload is that group of systems, which are actually concerned with receiving and retransmitting signals. These are the systems, which allow the typical communications satellite to serve as a “bent-pipe”, taking a satellite terminal’s uplink, and then converting it into a downlink. A satellite, which amplifies an uplink before re-transmission, is known as a “regenerative” satellite, while one, which rebroadcasts with no additional amplification, is called “transparent”. The spacecraft bus is the aggregate of all satellite subsystems not directly involved in communications functions. The spacecraft bus is responsible for on-board maintenance of satellite systems, heating or cooling the satellite, and notification of the satellite’s controllers as to the satellite’s location, health, and usage. The spacecraft bus is also responsible for powering the satellite, as well as any movement that may be required.

9

Satellite Space Segment (2)

Above is a graphic depiction of a satellite’s coverage area, or “footprint.” A satellite’s footprint corresponds to the areas of the Earth, which it covers. Any satellite terminal within a satellite’s footprint is capable of communicating with that satellite. This example depicts a satellite in geosynchronous orbit over the Pacific Ocean. The larger oval is the satellite’s “Earth Coverage” capability. As with all geosynchronous satellites, this is roughly one third of the Earth’s surface. However, applying satellite resources equally over the whole of the Pacific basin would be wasteful. The satellite’s resources are therefore concentrated on the continental United States, as well as Hawaii. This coverage, called “Narrow Coverage”, is represented in the graphic by the two groups of concentric circles. Graphics such as these are important when initially planning a satellite link budget, since each ring from the center represents a drop of 1 dB of gain. For every 3 dB of gain lost the power of the signal drops by half. This loss in gain is a result of the Earth being a sphere, as opposed to a flat surface. The shape of the Earth also results in the Narrow Coverage being ovoid, as opposed to perfectly spherical.

10

Satellite Access via FDMA

The above depicts two users communicating via an FDMA link. The center graphic depicts what the FDMA carrier would look like when viewed with a Spectrum Analyzer. The carrier consists of a center frequency, as well as a certain amount of satellite bandwidth. The more bandwidth allocated to the carrier, the wider it will appear on the spectrum analyzer. This bandwidth is in use whether or not the two users are communicating. While FDMA provides a convenient, reliable, “always-on” communications capability, overuse of this access technique can quickly use up precious satellite resources.

11

Satellite Access via TDMA

This graphic shows a TDMA satellite link. Since the users are not currently communicating, there is no satellite bandwidth utilized. This unutilized bandwidth can now be allocated to other users who are communicating. Bandwidth allocation within a TDMA network is much more efficient than one based on FDMA. However, due to the nature of a TDMA network, careful administration must occur to prevent saturation of the satellite network.

12

Notes Page

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13

Linkway™ Overview

15

Terminal Equipment (1)

Patch PanelEthernet

Switch

NMS Computer

Linkway TDMA Modem - MRT

Backup Linkway TDMA Modem - AMRT

KVM Switch

NCC

KVM Terminal

ANCC

Power Distribution Panel

Software Upgrade Panel

The NMS/NCC terminal equipment stack consists of several components. At the top of the stock is a signal patch panel, used for testing and integration of signals within the network.

Below the signal patch panel is a Software Upgrade Panel. This panel is

used as an access point to upgrade the Linkway modems and the NCC/ANCC. There is also a port to input an external 10 MHz Reference.

Below the Software Upgrade Panel is an Ethernet switch, which provides

connectivity for network devices, which utilize an RJ-45 connector.

Underneath the Ethernet switch are two Linkway modems, either S2s or S2Ss. The uppermost Linkway serves as the designated Master reference Terminal (MRT), while the lower Linkway is AMRT. In the example above, they are both Linkway 2100s.

Beneath the Linkway modems are the systems used in operating and

configuring the NCC and the ANCC. The first is a KVM (Keyboard-Video-Monitor) switch, which connects to the NCC, followed by the NCC itself. Below these devices are the KVM monitor, and the ANCC. The lowermost component of the stack is a power distribution panel.

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• Patch Panel– Provides a means to route signals between units

within the terminal and to transmit/receive RF.

• Software Upgrade Panel– Provides an easy access point to install software

upgrades to the equipment. Also provides a port to input a 10 MHz Reference

• Ethernet Switch– Layer 2 (Ethernet) aggregation point for the MRT sub-

system.


• NMS Computer– Network Management System (NMS) Computer is the

principle administrator interface with the Network Control Center (NCC).

• Linkway TDMA Modem– Primary TDMA modem. This is the MRT.

• Backup Linkway TDMA Modem– Secondary TDMA Modem - AMRT

• KVMSwitch– Allows operator to select screen display on KVM between

NMS Computer, NCC or ANCC.• Position 1 = NCC• Position 2 = ANCC• Position 3 = NMS

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• NCC– Network Control Center. SUN server that acts as

the centralized control point for the LinkwayNetwork.

• ANCC– Alternate Network Control Center. This server acts

as a backup to the NCC.

• Power Distribution Panel– Routes power to the units mounted in this

equipment rack. Provides surge protection.

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Linkway IP Modem

• Multi-carrier, multi-rate, TDMA Modem.• Up to 256 carriers can be supported in a Linkway

network.• All carriers on a transponder can be shared by all users

dynamically on demand.• Accepts IP inputs via 10baseT, 8-pin RJ-45 jack.• Maximum input data rate is 4 Mbps duplex.• Output is a L-band carrier at 5 Msps bandwidth.• TT Linkway IP modem and MRT Linkway IP modem are

identical with the exception MRT Linkway IP modem is used by the NCC to communicate with all other Linkwayterminals in the network and does not carry traffic.

The Linkway IP Modem is a multi-carrier, multi-rate TDMA modem. It routes traffic within the network in which it is configured using IP addressing. Unlike the IP-capable devices, which you may be more familiar with, the Linkway modems’ IPs are not propagated throughout the rest of the data network and the internet. Instead, data from the Linkway is routed within a closed Class A IP address. This IP address will vary depending on how the terminal was configured at the NMS. Since the Linkway modem transmits a TDMA signal, all Linkways within a network share the satellite bandwidth allocated to that network. Rather than having a static set of frequencies on which to transmit, Linkways instead dynamically acquire bandwidth from the pool that the network has been allocated. An MRT or Alternate Master Reference Terminal (AMRT) is essentially the same as a Linkway found on an STT, SPOP, or SNAP, with the exception that it does pass traffic as these terminals do.

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Network Control Center (NCC)

• Central control for the Linkway network.• NCC software is installed on a single rack unit Sunfire™

V210 server.– UltraSPARC™ IIi 1.34 GHz processor.– 512 MB RAM– 36 GB hard drive– Full color video card– DVD/CD combo drive

• Also acts as a web server to accept NMS commands.• Communicates with the Linkway IP via layer 2 through

the Ethernet Switch.

The NCC is the central control for the TDMA Network. The NCC has software on a Unix based server and also has Java Enterprise System software installed.

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Network Management System (NMS)

• Web based, used for monitoring network status and performance, and for performing modifications to the network.

NOTE:Linkway Operating Software Prior To Release 6.0 Must Use Netscape Version 4.79 In Order For The Nms To

Function.

• Primary interface is using MS Windows IE browser• Installed on an external laptop.• Principle administrator interface with the NCC.

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Typical Linkway Network

• Master Reference Terminal (MRT) – Controls network timing and resource allocation. DOES NOT CARRY NETWORK DATA.

• Traffic Terminal (TT) – Interface between terrestrial and TDMA network.

• Alternate MRT (AMRT) – Backup terminal for the MRT. DOES NOT CARRY NETWORK DATA.

• Supports Star, Hybrid, and Mesh Topologies.

A typical Linkway network consists of an MRT, an AMRT, and a number of Traffic Terminals. The AMRT serves as a backup to the MRT if it should fail for any reason. As previously stated, neither the MRT nor the AMRT actually passes traffic. A Linkway network can be configured as a star, hybrid, or mesh topology, all of which will be explained in more depth in the following sections.

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Star Topology

• Central hub with many remotes.• Remotes can only communicate via the hub.• Hub is usually assigned to administer the network.

Hub2 or more Linkway Modems

The Star topology is the most basic of topologies. In this topology, also known as a “Hub and Spoke,” each Traffic Terminal within the network is only communicating through the MRT or AMRT. Individual terminals do not communicate directly with other in this topology, only with the MRT. The disadvantage of this topology is that all traffic must be processed through the MRT, which can possibly cause congestion within the network.

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Mesh Topology

• Many terminals, no centralized hub location.• One or two terminals assigned to administer the network.• This topology resembles a Brigade’s JNN architecture.

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Hybrid Topology

• Consists of two or more hubs.• Provides mesh connectivity between hubs.• Terminal must communicate through a hub.

Hub

Hub

Hub

Redundancy Options

• The MRT and AMRT when located together is known as Local Redundancy.

• When the MRT and AMRT are located at separate sites is geographic redundancy.

• Push package employs local redundancy.• MRT and AMRT are peers.• Alternate is not a hot spare.• Upon MRT failure, the NCC will command switch

to AMRT.• When MRT recovers, there is not an auto switch

back.

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Local Redundancy Example

• In normal operations the NCC is controlling the network, NCC and ANCC are peers.• The ANCC is updated with any network changes via a database update from the

NCC every 7 minutes.• The NCC/ANCC are continually pinged by each other to ensure operation.• If no ping response, ANCC verifies switch function than assumes control of the

network.• When NCC recovers, switch back does not occur.• NOTE: Having two active NCC’s on one network will result in network failure.

MRT

AMRT

NCC

ANCC

L-ban

d Co

mbin

er

Eth

ernet S

witch

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MRT System IP Addresses

NMS(10.1.1.5)

NCC(10.1.1.2)

ANCC(10.1.1.3)

Ethernet Switch(10.1.1.1)

MRT(10.1.1.4)

AMRT(10.1.1.9)

Each TT must be on an individual sub -net, examples:TT1 – 10.1..3.1TT2 – 10.1.4.1TT3 – 10.1.5.1

Set per Cut Sheet

The JNN subnet mask is 255.255.255.248 to allow six useable hosts per TT (or MRT/AMRT) modem.

The MRT is used for power balancing and pinging.

The AMRT is used for pinging.

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Questions?

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Notes Page

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Insert Tab # 3 Here

29

Linkway™ Principles of Operations

31

Bursts

• The Linkway network uses a series of bursts to establish/maintain timing and to pass data.– Reference (RB) – Carries NCC commands and timing

feedback to the network and establishes receive timing.– Acquisition (AB) - From TT’s to the NCC to establish

network timing, only used when a TT enters the network.– Control (CB) – From TT’s to the NCC to update the NCC

of TT status, the NCC uses this burst to maintain timing, and updates the TT’s during the next RB.

– Signaling (SB) – TT bandwidth requests to the NCC. Also known as Aloha bursts, a TT can transmit at any time. May result in collisions. In the case of collisions, MRT will reset timing and TT’s will again access network at random times.

– Traffic (TB) – Data carrier from TT to TT.

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Bursts Example (1)

• NCC establishes the network via the MRT.– MRT transmits RB.

– MRT receives original RB.

– NCC uses time between RB transmit and receive to establish network timing and synchronization.

MRT

NCC

The MRT must lock on itself before any traffic terminals can acquire.

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• NCC begins TT synchronization via the MRT.– MRT transmits RB.

– TT’s receives RB and establish timing reference.

– TT’s read RB to establish AB assignment.

– TT’s continue to receive RB every frame to maintain timing reference.

MRT

NCC

RB

TTTT

TT

Bursts Example (2)

The Reference Burst (RB) conveys outbound NCC signaling, conveys timing feedback data to traffics terminals, and establishes receive timing.

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• After TT’s are receive synched they must become transmit synched to enter the network.– Each TT has been assigned a

specific AB burst time to prevent collisions.

– AB’s have an impact time window of 40,000 clocks to allow for timing error.

– NCC via the MRT sends RB containing timing corrections to specific TT.

– A TT is considered transmit synched when it sends 3 AB frames at exact correct clock.

MRT

NCC

AB

TTTT

TT

RB

Bursts Example (3)

Acquisition Burst (AB) conveys transmit response message and acquires traffic terminal transmit timing.

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• After a TT has achieved network synch, AB is no longer used, TT’s now transmit CB.– Each TT is assigned a

specific control frame ID.

– CB contains TT status and bandwidth reporter message.

– MRT receives CB and measures timing and frequency

– NCC sends corrections to TT’s. Corrections keep TT’s synchronized with satellite movements.

MRT

NCC

CB

TTTT

TT

RB

Bursts Example (4)

Control Burst (CB or QB) conveys traffic terminal status report and is used to maintain traffic terminal transmit timing.

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• When a TT needs more bandwidth to send traffic it sends a SB to the MRT.– SB’s are Aloha Bursts and

subject to collisions.

– If a TT does not receive a burst assignment to send traffic, it sends the request again on a SB.

MRT

NCC

CB

TT

TT

TT

RB

Bursts Example (5)

Signaling Burst (SB) conveys inbound traffic terminal signaling.

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• TT’s transport data from site to site using traffic bursts.– In smaller networks only

carrier “0”, is utilized.

– As network demand increases, additional carriers may be added with the proper approval.

– Additional carrier enlarges the bandwidth pool that is assigned as needed.MRT

NCC

CB

TT

TT

TT

RB

TB

Bursts Example (6)

Transmit Burst (TB) conveys circuit and packet data.

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Questions?

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Insert Tab # 4 Here

39

TDMA Network Configuration

41

Terms to Know

• Hyper Terminal – A protocol that allows a computer to function as a terminal working from a remote computer.

• PSFTP- Putty SSH File Transfer Protocol- A secure protocol governing the transfer of files from one computer to another over a network.

• Boot File – As pertains to Linkway; the file that contains the operating parameters of the modem; the file is loaded into the modem during boot. Typical Information in a boot file includes data about transmitting, receiving, symbol rate, forward error correction (FEC), terminal id, and a few other parameters.

Step by Step Startup

NOTE: The following assumes the antenna has been peaked and polled on the satellite.

• Configure Network and generate boot files.• PSFTP boot files from NCC to NMS. NOTE: The

boot files will have to be transported to the TT sites via e-mail, memory stick or some other means.

• Load boot files.• Access the satellite per operator’s instructions

with CW.• Verify network performance, MAINTENANCE.

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Starting the NCC

• On the NCC log into the Sun server as user: linkway.

• Open a terminal window.• At the prompt type: ncc_start<enter>• Start the ANCC only AFTER all configuration

is complete.• After any changes to the NCC database, the

NCC must be restarted for changes to take effect.

Starting, stopping, or making changes to the NCC can also be accomplished remotely via Telnet or another remote access client such as PuTTy. While the interface is not as user-friendly (there are no icons, nor is the mouse enabled), it remains an option for remote access. To connect to the NCC remotely, first Telnet to its IP address. Next, login normally as user linkway. From the linkway user prompt, continue as above.

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Starting the NCC

• To verify the NCC is running, in the terminal window type: ncc_stat<enter>

• You should see the following:

NMS

• In addition to NCC processes, a web server also runs on the active NCC.

• Providing connectivity exists, any web client requests may access the NMS via a web browser.

• Primary interface for system administration and day to day operation.

• In Linkway 6.0 and greater the NMS can not control the MRT until the MRT is in the network.

• If there is a change in status (whether operator change or database change), the NMS screen needs to be refreshed to view the changes.

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NMS Login

• To browse to the server enter the IP of the active NCC, with :30000 at the end.– Example: http://10.1.1.2:30000 for the NCC.

• ANCC will not support NMS processes unless it becomes active.• Enter User id: linkway• Enter Password: linkway• Click the Submit Login button

NMS Login – The NMS Login is the web-based, Graphical User Interface (GUI) to the NCC. It provides a visual, “point-and-click” configuration option for each Linkway network segment, as well as a variety of diagnostic tools and views. Since the NMS is located on the NCC, the NMS cannot be used on the ANCC unless the NCC has failed and the ANCC has taken control of the network. Since the NCC and ANCC have separate IP addresses, it is important to know which one is in control of the network, as only the IP address of the active NCC will allow the NMS to connect.

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NMS Main Screen

NCC Connection Status

Up = GreenDown = Red

Network Admin Status

Enabled = GreenDisenabled = Red

Terminal Count Up / Down status

Menu Buttons

MRT IDMRT Always 120

Network Admin Status – This display shows the level or privileges available to the user currently logged into the NMS. If the user has admin privileges, this will be green. If the user can only view the NMS’ configuration, but not make any changes, this will be red. NCC Connection Status – This displays the status of the current connection status to the NCC. Please note that if the connection between the NCC and the NMS is lost, then restored, the Connection Status indicator will continue to display red. Before the NMS will recognize the restored connection, the web interface must be refreshed. Ref. Terminal ID – The reference terminal ID shows the terminal ID (in hexadecimal format) of the reference terminal currently acting as the MRT. If the primary MRT is controlling the network, then this will display “0x00000120.” If the MRT passes control of the network to the AMRT, this will display “0x00000140.” These hexadecimal values are always applied to the MRT and the AMRT. They will not change regardless of network configuration. Menu Buttons – These provide a graphical user interface (GUI) to access the Linkway network’s configuration and management functions.

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NMS MAP

The NMS Map allows the operator to view the location of all the terminals programmed in the NMS. This is important, an incorrect latitude or longitude can cause the terminal to not access the network. The Linkway system can find a terminal within a 50-mile radius of the designated coordinates. Any changes to a terminal’s location can be viewed on the map. The map provides indication on the status of each terminal also. Terminals that are in the network will be green and red indicates the terminal is not in the network.

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Network Status

• Accessed from main screen Network Status button.

• Lists Terminal ID, Terminal Names, Status, and Alarms for every terminal configured in the network.

Network Status – The Network Status screen provides a list of Terminal IDs within the network and information about those terminals, specifically their names, transmit/receive status, and alarms. While the Network Status screen can be accessed from the main NMS screen, it will also appear as a pop-up if a terminal experiences a change in status or alarm state, but only if the NMS is currently connected to the active NCC. A terminal’s status will only appear as “Up” once it has successfully synchronized with the MRT.

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Network Status – Event Log

• Lists all events logged in the NCC since last reset.

Network Status – Event Log – Any event, such as a status change or alarm within the network, will appear in the Event Log. The Event Log will record every event that occurs on the network since the NMS was started, or since the last reset of the Event Log itself. To clear the Event Log, click on the “Reset” button on the bottom of the Event Log screen.

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Configuration

• Site configuration can be made by right-clicking sites or by utilizing the wizard. More on this later in the lesson.

Configuration – The Wizard is the preferred method for introducing new terminals to the MRT. Changes to existing terminals as well as creating new terminals can also be done by right-clicking sites as shown above.

Note: The MRT cannot be configured with the Wizard; all other terminals can including

the AMRT.

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BurstTimePlan

• Accessed from main screen Burst Time Plan button.

• Displays current burst time plan.

• Updated real time.

The Burst Time Plan The burst time plan is a graphical representation of bursts, and thus traffic within the network. Since each burst on the TDMA network is approximately 28 ms in duration, each individual burst cannot be displayed. The burst time plan is therefore only a rough approximation of traffic, and should not be taken as completely accurate. It does, however, serve as a useful guideline in determining what traffic is going over which carrier, and to which degree, since each individual burst (represented as a colored bar) corresponds to a different kind of burst. The key for the colors of burst are located in the lower-right hand corner of the screen when the burst time plan is displayed. Located on the left hand side of the screen are the carrier IDs for each carrier within the network. Carrier IDs begin with Carrier 0 (on which all network administrative bursts, such as reference and signaling bursts, are displayed), and typically continue in sequential order.

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Diagnostic Tests

• Accessed from main screen Diagnostic Tests button.

• Primary interface to run tests on the system.

• Tests can be selected via a pull down menu, or by typing the command in the command line.

Diagnostic Tests – The Diagnostic Tests screen provides a variety of tools to assess the health and functionality of the Linkway network. While all the test commands can be entered directly into a Linkway modem, the Diagnostic Tests screen provides a GUI that allows the NMS operator to quickly and easily enter these commands into any Linkway currently synced with the network. The default terminal ID in the “To Terminal” dropdown box in the upper portion of the screen is “0x00000120”, which is the terminal ID of the MRT. However, by changing the terminal ID in the “To Terminal” dropdown, the same diagnostic commands can be sent to any terminal currently synced with the MRT. The result of these tests will be the same as if they were entered locally at the distant end. Obviously, if a terminal is not synced with the MRT, these tests cannot be performed from this screen.

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User Admin

• Accessed from main screen Administration button.

• Primary interface to view, delete, or add users.

Operation

During setup of the MRT the following major steps shall be accomplished.

1.Power-up the MRT2.Perform Space Segment Configuration3.Perform Site and Terminal Configuration4.Perform IP Configuration5.Generate Boot Files6.Load Boot Files7.Synchronize Database8.Access Satellite9.Enter Network10.Verify Modem Performance

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Power Up the Equipment Rack (1)

1. Inspect the Power Distribution unit and insure the main power switch is in the off position and that all of the rack elevation rocker positions are in the off position (lower half depressed).

Main Power SwitchRack Elevation Rocker Switches

2. Locate the power cord in the rear of the equipment rack and plug it into a convenient 110 VAC outlet in the center section of the STT.

3. Connect STT ground strap to MRT Package ground block.

4. Position the main power switch on the Power Distribution Unit (PDU) to the ON position.

5. Place each rocker switch to the on position (top half depressed).

6. Power up the NMS computer.


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7. Power up the NCC and the ANCC by releasing the covers and pressing the power switches located at the front of the servers.

8. Using two people, slide the rack into the center section of the STT.

9. Right-click on the NMS computer control pad. A window will appear at the approximate position of the cursor.

10. Navigate from this window as indicated below through Graphics Options to Dual Notebook and Monitor.


11. Open the KVM terminal.12. Select position 1 on the switch panel. You will see the Welcome to

NCC Screen after the units completes power-up.13. Enter linkway for the User Name.14. Enter datapath for the password. Note that the cursor will remain

stationary while the password is being entered, this is normal.15. The screen will display a navigation banner across the bottom

after a successful logon.16. Hover the cursor over the various icons and examine the names

of each selection group. Hover over the group titled Hosts, then select This Host. A new window will display.

17. Start the NCC by typing the following command; ncc_start.18. Press enter.


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19. Monitor status of the NCC as it starts by entering the command ncc_stat, then press enter. A two-column response display will appear. Repeat this command every minute until each Process ID (PID) in the right-hand column has a number assigned. This indicates that the NCC is up and operational. DO NOT START THE ANCC UNTIL ALL CONFIGURATIONS ARE COMPLETE.

20. Select position 3 on the switch panel. This will result in the NMS being displayed on the KVM.

21. Double-click on Internet Explorer. A screen will appear that requests a username and password. NOTE: ENSURE THE ADDRESS FOR THE APPROPRIATE NCC IS ENTERED IN THE ADDRESS BAR OF INTERNET EXPLORER.

22. Enter linkway for the username and password. The screen shall change to NMS Main Screen.


Note: You may be prompted to change the passwords for the NCC. If so, ensure that you change the password for the super user account. This is done by logging in

as: user and a password of: root. It will then prompt you to change the password.

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Questions?

TAB

Insert Tab # 5 Here

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Configuration

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Modifying Carrier 0

Modifying Carrier 0• Log on to the NCC

- Username: linkway- Password: datapath

• Open a file manager window- Navigate to the

“home/linkway/etc.datapath/etc/db” directory

• Copy file and paste in the dbnew directory• Double click on the carrier.tdb file• Edit and save the file

Carrier 0 is the default carrier, and can only be modified at the server

All other carriers can be added through the Internet Explorer web interface found on the NMS laptop

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Space Segment Configuration (1)

• From the Configuration

• screen

Click-Space Segment

Configuration

Select-Network

Configuration

Click-OK


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• Select NetworkConfiguration\

IF Loop pull down menu• Yes (IF Loop enabled)• No (Normal operations)

Name Field• Enter the name of the satellite.

Nominal Longitude• Enter the orbital longitude of the

satellite (degrees East)– If cut-sheets list orbital

longitude in degrees West, subtract from 360

• NCC uses this information to calculate network timing

• NCC processes must be stopped and re-started for these changes to take effect


If the network is set-up to operate in IF Loop and not transmit over satellite, select “yes” from the drop-down menu. This will be the selection chosen if using a satellite simulator. The IF Loop tells the system not to calculate for satellite latency. If the network is to transmit over the satellite, select “no” from the drop-down network and the Linkway terminals will use their NMS assigned latitude and longitude to calculate delay over satellite for their network timing. If this is defined incorrectly, the terminals will not be able to synchronize with the network. To recognize any changes, the NCC will have to be stopped and restarted.

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Adding Carriers (1)

• Expand the Linkway

and Network folders

• Right click-Carrier

Administration

• Select-Carrier

Administration

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• Notice Carrier ID 0 is already populated.

• Carrier 0 was configured during the modification of the “carrier.tdb” file

• Click “Add” to create another carrier

Adding Carriers (2)

Carrier 0 is the only carrier to be configured in the NCC. All other carriers are configured through this method.

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Enter data from Network ConfigurationPlan (cut-sheets)-Carrier Id: (cut-sheets)-Transponder Id: 0 -Symbol/sec: (cut-sheets)-FEC: (cut-sheets)

Set TX and RX offsets to “0”

Enter the TX frequency: (cut sheets)-Make sure you enter in KHz-Should be a total of 8 digits

Enter your RX frequency: (cut sheets)-Also in KHz

Set RX IF Offset to “0”

Leave Control Group Mapping source and destination at “0”.

Adding Carriers (3)

1. Click “Add Carrier Admin” to enable the carrier administration functions

2. Click “Add Carrier” to save the new carrier configuration

3. Clicking the “Close” button Control Group Mapping—Carriers are uni-directional, having a source and

destination. Each control group in a network must be mapped to use a carrier or they will have no access. If a control group is to have access to this carrier, it must be mapped with a source CG and destination CG. If the source and destination are the same CG, the group will have transmit and receive access over the carrier. Assign the source and destination control groups.

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• The Carrier Administration now displays 2 carriers

• Carrier 0 (the default carrier)

• Carrier 1 (the new carrier)

Adding Carriers (4)

MRT Site Configuration (1)

• Expand the site folder

• Right click MRT Site

• Select Configure Site

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Enter appropriate

information from

the cut-sheets


It is important to enter the correct values here. If entered incorrectly, the MRT may not function correctly. The above example shows an incorrect value that will cause the MRT to not function. You must be prudent when inputting configurations.

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• Select “Non M&C”

• Select the “ODU” Tab

• Make sure that the “BUC Power” and “LNB

Power” options are

NOT checked


Click the “Submit” button

A pop-up window will appear

Select “Yes”

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You must now configurethe MRT’s IP address and Subnet Mask

• Right click on “MRT Site”

• Position mouse pointer over Site Protocols, Configuration, and select “IP”


The Protocol Configuration

window will appear

• Click “Configure” to

configure the IP interface for the MRT

Note: The status is

disabled until the MRT IP is

configured.


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• Ensure the MTU size is 1500 bytes

• Enter the IP Address for the MRT modem-10.1.1.4

• Set the subnet mask to:-255.255.255.248

• Routing protocol is: None

• Click “Submit” to apply theconfiguration changes


The Protocol Configuration

window displays information

regarding the interface you

just configured.

• Click “Close” when finished

Note: The status is now

enabled.


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Configuring AMRT & TTs (1)

From the Main

Screen

• Click “Wizards”

• Click “Add New

Site Wizard”

• Click “OK”

All other terminals can be configured through the wizard. This is the preferred method because of the simplicity of its design. The wizard walks the operator through each step of adding a terminal.

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• To add a new site,

click the “Next”

button

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Site Type allows

the decision

between AMRT

and Traffic

terminal Sites.

Note: Be aware

of the choice

made. An

incorrect

selection will

affect operation

of the terminal.

There is an option to create the MRT through the wizard. This is not to be done.

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Linkway• Select the type of modem

Site Type• Choose appropriate terminal

type from the pull-down menu

Control Group• Set to “0” for AMRT,

choose correct control group for TTs

Site ID• Auto assigned

Site Name• Cut-sheets.

• Enter Longitude and Latitude from Cut-sheets

• Click “Next”

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ODU Type- No M&C

BUC Power-NOT Checked for AMRT, varies with TT Types

LNB Control• No Checks for AMRT, varies with TT

types

Spectral Inversion• Not Checked.

BUC LO• 13050 for AMRT, varies with TT types

LNB LO• Depends on LNB used

- 10750, 10000, 11250, or 11300

• RF Center Frequency auto populates- Click “Next” when finished

The transmit and receive center frequencies shown here are used as a reference. While the calculations for determining a site’s center frequency remain the same, if the site’s BUC or LNB are changed so that it uses a different local oscillator frequency, these calculations will have to reflect that change.

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Name- Auto populates

Accounting- Normal

Max Tx carrier rate- Cut-sheet

Tx Power:-15

Configure Terminal IP interface?- Yes

- Click “Next”

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IP Address-From Cut-sheet

Subnet Mask- Cut-sheet

Routing Protocol- None

- Click “Finish”

It is critical to input the correct IP for the terminal. Depending on the skill level of the TTs operator, an incorrect IP can be difficult to find. An incorrect IP will cause the Linkway to be on a different network than the baseband equipment, which will stop the flow of data.

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IP PVC Configuration (1)

To configure the IP PVC’s, for the TT’s, follow these steps…• Right click on the Sites folder• Roll the mouse arrow over Network Protocols, PVC’s, and select IP PVC.

Permanent Virtual Circuit (PVC) - A logical circuit between modems, for the purposes of efficiently routing data to the appropriate destination Every terminal in the network has the possibility of a virtual connection over the satellite to every other terminal in the network resulting in full mesh connectivity. In order to use this connectivity, a PVC must be defined between all terminals exchanging traffic. PVCs are bi-directional (accept forward and backward traffic), so it is only necessary to configure a PVC once between two sites. Whether a terminal is defined as a source or destination terminal, the PVC is defined for traffic originating at either site.

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When the IP PVC’s window opens, it will display any current PVC’s for

the TDMA network.

• Click the “Add” button.

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When the IP PVC Details window opens, enter the following…• Mode: Unicast• Source: (from cut-sheet) Select source site from pull-down• Interface: 2• Destination: (from cut-sheet) Select destination site from pull-down• CIR (Committed Information Rate): 0• Click “Submit” to load the new PVC(‘s)

JNN typically has a CIR of 0 and 0 but if using for power balancing, use 64 and 64. This way all the circuits will have the same data rates and is easier to see if a circuit is power balanced as referenced to all the other circuits.

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Auto vs Manual PVC’s

• Auto PVC’s make a logical connection to every terminal in the network to every other terminal in the network.– Make connections that are not needed.

– Clog the network with unwanted bandwidth

• Manual PVC’s makes the operator determine which terminals talk to other terminals.– Miss connections that may be needed

– Must have logical method of keeping track of network

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Questions?

82

Notes Page

TAB

Insert Tab # 6 Here

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Generating Boot Files

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Generating Boot Files (1)

• New boot files need to be generated:– New network configuration is complete.

– The following changes are made to an active network:

• Transmit and/or Receive center frequencies

• Carrier 0 frequency

• TDMA Frame Structure

• Site Identity

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• In the Diagnostic Screen:

– In the Command field type makeboot

– In the To Terminal Field select NCC from the pull down menu.

– Click the SendButton.

– You should see confirmation of one boot file made for each terminal configured.

– File boot.420 is for terminal 420 etc.

Remember that the Diagnostic Screen is just a GUI to the NCC. The “makeboot” command can also be entered directly into the command prompt of the NCC.

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• Now that the boot files are generated they have to be moved from the NCC Sun box to the NMS Laptop.

• We PSFTP the boot files from the NCC to the NMS.

• PSFTP should be downloaded providing an icon on the NMS.

PSFTP is a secure file transfer protocol that has replaced FTP for transferring boot files.

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Generating Boot Files / FTP (1)

• Click on the PSFTP icon.

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• Open a connection with the NCC

• Enter the username and password for the NCC

Enter the command “open 10.1.1.2”. This makes a connection with the NCC. You will then be prompted for the login, “linkway” and the password, “datapath”.

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• At the prompt type you will type the command line to transfer the boot file

This first command line listed will transfer all the boot files created.

“mget /home/linkway/etc.datapath/etc/bootdb/boot.*” This next command line will transfer just one boot file. The boot file transferred must be specified. Below is just an example. Notice boot file 120 is specified.

“get /home/linkway/etc.datapath/etc/bootdb/boot.120” After using one of these commands, the boot files will appear on the desktop of the NMS. The PSFTP session is then ended by typing “bye” or “quit”.

Example: get/home/linkway/etc.datapath/etc/bootdb/boot.120

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Common PSFTP Commands

• bye finish your SFTP session

• get download a file from the server to your local machine

• ls list remote files

• mget download multiple files at once

• open connect to a host

• quit finish your SFTP session

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Load the Bootfile

• After generating bootfiles for your network, begin by loading the MRT’s bootfile, identified as Terminal 120. This process is the same as if the MRT Linkway modem was in an STT.

Ensure the console cable is connected from the NMS to the correct

modem console port on the patch panel

Double click the modem HyperTerminal shortcut icon on the NMS desktop.

Login as “root”. If prompted for a password, use the factory set or unit

designated password.

From the # prompt select Transfer and “Send Text File.”

In the explorer window, navigate to wherever you have saved the Bootfiles

In the “Files of type” drop-down menu, select All files (*.*).

Double click the file you want to load

The screen will scroll up as the boot file loads into the modem.

Type “reboot” after the boot file has finished loading

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Database Synchronization

After all configurations have been completed the NCC and ANCC must have their databases synchronized.

On the NCC…• Navigate to /home/linkway/etc.datapath• Delete the “ANCC.previous” file

On the ANCC…• Navigate to /home/linkway/etc.datapath• Delete the “NCC.previous” file

Start the backup server by typing “ncc_start” <Enter>

Doing this forces the inactive server to download the current network configuration, which synchronizes the two databases (only after an NCC_START). This process can take up to 1 hour to complete.

Access the Satellite

• Once the NCC and ANCC databases have been synced, the satellite terminal serving as the host for the MRT may access the satellite.

– If the terminal is already on the bird, contact the controllers to access the carrier.

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Entering the Network (1)

• The modem will receive synch, indicated by a blinking “SAT” light.

• The modem will then transmit synch, indicated by a solid “SAT” light.

• MRT site should be green on the NMS.

Entering the Network (2)

• Verify TT’s are entering the network.

• If not, assist as applicable.

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Verify Modem Performance (1)

• The following steps should be performed upon entrance into the TDMA network and then daily as part of routine maintenance.

• In the Diagnostics window enter the command cb, then select the MRT from the pull down window, then click on the Send button.– The clear burst command will erase all burst statistics.

• In the Diagnostics window enter the command rbtp, then send it to the MRT.– Displays receive burst time plan of the modem.– Used to identify bursts and from which terminal they are

coming from.

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RBTP Status FieldsList the ID, type, transmit and receive terminals, and all other relative carrier information.

Verify the “Power” is within the +/10 dB burst-to-burst dynamic range (nominally these should be adjusted to as close to zero as possible). Also, verify that there are no “CRCErrs” reported. To determine what site is the source of the burst, use the command “rbtp” in conjunction with the command “rb”.

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• In the Diagnostic window enter the command rx, then send it to the MRT.– Displays receive status of the modem.

– Powerful tool for maintenance and troubleshooting.• Allows user to identify bursts ID between terminals.


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• Receive Status Fields– State

• RxSynced – TT modem has locked on to the reference burst.

• Search – TT modem has not locked on to the reference burst.

– If the modem stays in this state for several minutes verify the MRT is transmitting and there are no local downlink problems.


• Receive Status Fields– RefBurstRawBer – BER of the modem pre FEC.

• Should be 10E-3 or better. If below indicates a problem that will have to be isolated.

– Rxatten – Value of the modems internal attenuator setting, range of 0 – 40.

• Optimal setting is 20. NOTE: NOT REQUIRED TO BE AT 20. JNN is typically at 36 – 28.

• If setting is near or at maximum, attenuation may have to be added to the receive chain.

• If setting is near or at minimum, power may have to be added at the MRT, or attenuation taken out of the MRT transmit chain.

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• In the Diagnostic window enter the command rb, then hit send it to the MRT.– Displays reference burst statistics of the modem.

– Ensures power is not too high or too low.

By entering the “rb” command, the power levels (as well as other receive statistics) can be viewed for terminals connected to the MRT. The close monitoring of power levels is important, since a network, which is pushing too much, or too little power is inefficient. The process of gradually adjusting power (or, alternatively, attenuation), is known as power balancing. Power balancing is an important daily task, which must be performed on the TDMA network, since a number of factors (such as atmospheric attenuation) can cause a terminal’s power level to drop or rise.

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Above is a visual representation of the Diagnostic screen when the “rb” command is entered. This command shows the receive bursts statistics for all sites shooting into the terminal in which the command was entered, in this case, the MRT or AMRT. The first terminal identified is the MRT’s receive bursts statistics, followed by the other terminals within the network. The receive bursts statistics for this particular network are particularly poor, as can be seen from the screenshot. All terminals are experiencing massive amounts of “misses,” meaning they did not receive the burst when they were expecting to, and Terminal 3 is being forced to make a large number of Viterbi corrections, indicating that it is taking many forward errors. Additionally, Terminal 3 is experiencing many CRC (Cyclic Redundancy Check) errors, meaning that the data it is receiving from the MRT is heavily corrupted.

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• Reference Burst Status Fields– Burst ID 1, the MRT reference burst is the most

important burst. TT will not remain in the network without the reference burst.

– Detects – Number of times the modem has “detected”, or received the RB.

• Number should be steadily increasing.

– Misses – Number of times the modem has NOT received the RB.

• Number should be very small, if the number continues to increase, the problem will have to be isolated.

Detects – This is the number of times that the distant end terminal has received, or “detected” receive bursts from the MRT. This number will gradually rise as the terminal becomes synced with the network, and should continue to do so as long as the terminal remains synced. The “Detects” field will reset itself after 40,000 receive bursts have been detected, or an operator enters the “cb” command, which will clear burst statistics. Misses – This is the number of times the terminal has not detected the receive burst when it was expected. The number of misses may rise during initial syncing of the terminal, but should not continue to rise by a noticeable degree once the terminal is fully synced. If the number of misses does continue to rise, there is likely a problem with the terminal's receive, or, possibly, with the TDMA network itself.

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• Reference Burst Status Fields– VitCorrs – Number of Viterbi corrections performed

by the modem.• Should be low, but some will always be present, compare

over 24 hour window to baseline system.

• If the number is increasing rapidly, indicates a problem that will have to be isolated.

– FrEr – Frequency Error in Hertz.• Within +/- 100 Hertz

• If not, contact customer service.

• Modem will have to be replaced with a known good modem.

Viterbi Corrections – Invented by Andrew Viterbi in the 1960’s, the Viterbi Algorithm is a mathematical means of predicting and correcting errors, or Forward Error Correction. While there will always be a small number of Viterbi Corrections (since no means of RF transmission is free of errors), a rising number of Viterbi Corrections indicates that the data being received is increasingly full of errors. If the number of Viterbi Corrections continues to rise, there is a problem within the network. The recommended timeframe over which to compare Viterbi Corrections is 24 hours. Frequency Errors – Since TDMA bursts occur over a number of frequencies within an allocated block, they must be very precise. If the TDMA modem is experiencing frequency deviation of more than 100 Hz, it is most likely malfunctioning and must be replaced with a new modem.

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• Reference Burst Status Fields– Power – Receive power in dB’s.

• Range +6 to -6• Should be within .5 of 0, 0 = - 55 dBm.• If not within .5 of 0, using the NMS raise/lower power on

the MRT until the power is correct.• Repeat power balancing on all terminals in the network,

MRT to TT, and TT to TT.– RSCorrs – Number of Reed-Solomon corrections.

• Should be low, 10 to 20 per day maximum.• A higher number indicates a degrading system and the

problem needs to be corrected.– CRCErrs – Number of uncorrectable errors.

• Steady/rapid increase indicates a poor RF link.• Link failure is highly probable, the problem needs

correction as soon as possible.

Power – This field is the receive power of the terminal in dB’s. The optimal receive power is within .5 dB of 0. If any terminal’s receive power is outside optimal, the network in all likelihood needs to be power balanced. Reed Solomon Corrections – Similar to Viterbi Corrections, should this number increase noticeably over a 24-hour period, there is a problem within the network. Cyclic Redundancy Check Errors – When sending data to another terminal, the MRT, uses an algorithm to create an alphanumeric representation of that data called a Cyclic Redundancy Check. If, when the distant end receives this information, it does not match the Cyclic Redundancy Check, it displays an error. If these errors continue to occur, the RF linkage between terminals is poor and troubleshooting should commence.

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• In the Diagnostic window enter the command show_ber, then send it to the MRT.– Displays raw BER statistics of the modem.


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• Show_BER Status Fields– Bits – Number of bits encountered, will increase over

time.

– BitErrors – Number of bit errors received. Will increase over time.

– BER – Raw Bit Error Rate.• Should be 10E-5 or better. If below indicates a problem that

will have to be isolated.

The “show_ber” command will display the BER or Bit Error Rate for the terminal. The Bit Error Rate is the number of errors that the terminal experiences compared to the number of bits it is actually receiving. For example, if ten bits are received as well as one error, the Bit Error Rate will be one in ten, or 0.1. This would be considered so high as to be unusable, and Bit Errors are typically only found for several million bits received. BER is shown using scientific notation, so a BER of 10E-6 would be 10, followed by zeroes, or 1,000,000, meaning one error is received for every million bits. Alternatively, this is an error rate of .0000001.

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• In the Diagnostic window enter the command tx, then send it to the MRT.– Displays transmit statistics of the modem.

The “tx” command is shorthand for “transmit.” As the name implies, it will display transmit statistics for any modem in which it is entered. This command will provide diagnostic and troubleshooting information in the event that a terminal is experiencing a degraded signal or is having trouble syncing with the network. Additionally, it will provide general performance information useful for peaking and polling, as well as increasing the efficiency of the network.

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• Transmit Status Fields– State

• TxSynced – TT modem has transmitted 3 consecutive AB’s at the correct time.

• Search – TT modem has not transmitted 3 consecutive AB’s at the correct time.

– If the modem stays in this state for several minutes verify the MRT is transmitting and there are no local downlink problems.

After entering the “tx” command, the whole of the terminal’s transmit status is displayed. The first line contains the transmit “State” in which the terminal is when the command is entered. When the terminal initially is powered up and has acquired receive sync, its transmit state will be “Search.” In the Search phase, the terminal has not yet sent three Acquisition Bursts in timing sync with the MRT. In other words, it is still searching for the synchronization acknowledgement from the MRT. Once the requisite Acquisition Bursts have been sent with the correct time, they enter the “TxSynced” or Transmit Synced state, meaning the terminal can now transmit over the network.

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• Transmit Status Fields– TxSyncLosts – Total number of times modem has

lost transmit synch.• Should be at or near 0.

– A steadily increasing value indicates a system problem that needs to be isolated and corrected.


• Repeat the above steps for EVERY terminal in the network.

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Verify TDMA Modem Performance

• Ping from Modem to Modem– In the Diagnostic window type the following

command:• ping xx.xx.xx.xx -t 4000

• ping (IP address of modem you are reaching) and –t = time 4000 ms

• Because of the bursty nature of the TDMA modem, ping must be held-up for a period of time to ensure a burst catches it.

Pinging can be a useful troubleshooting tool. This test will tell the operator if the link is fully up from Modem to Modem. If pings are lost, this can be an indication that further inspection of the link is needed.

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NCC Shutdown

• To shutdown the NCC Sun workstation use the following steps:– On the Sun workstation log on as user linkway.– Open a terminal window and type ncc_stop<enter> at the

prompt. This stops the NCC processes.– At the prompt type su<enter>– When the password is asked for, at the prompt type

root<enter>. You are now logged in as the super user.– At the prompt type: init 5– Press the y key in response to any confirmation questions.– Repeat the procedure for the ANCC.– FAILURE TO SHUTDOWN THE SUN WITHOUT USING

THE ABOVE PROCEDURE MAY RESULT IN DAMAGE TO DATA, FILE SYSTEM, AND OPERATING SYSTEM.

Questions?

TAB

Insert Tab # 7 Here

111

Troubleshooting and

Maintenance

113

Troubleshooting and Maintenance (1)

• If the MRT and/or AMRT are ever replaced the ethertab file in both the NCC and ANCC must be edited to reflect the new MAC address of the new Linkway.

• If not already open, open a file manager window.• Open the /home/linkway/etc.datapath/etc folder.• Double click on the ethertab file to open it in the text editor.• The first line of the file should appear similar to:

00 a0 94 00 51 37 21 #MRT• The second line of the file should appear similar to:

00 a9 84 00 52 36 41 #AMRT• Enter the MRT/AMRT Ethernet address into the file. The

address can be found on a sticker on the back of the Linkwaymodem.

• Do not change the 21/41 in the file; the only changes should be the first six pairs of numbers.

• Save the file and close the window.


• Symptom– MRT is the only terminal in the network that has achieved

transmit and receive sync.

• Cause– Wrong satellite information entered on the NMS.

• Symptom– The MRT will not transmit sync, attempts to receive sync

before bursting.

• Cause– NCC is not communicating with the MRT. Check the

following:• Ethertab file is correct.• Connection between NCC and Switch, and Switch and MRT

are correct. (Should be straight thru cables.)• Bad MRT or NCC, change to ANCC and/or AMRT.

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• Symptom– No terminals are achieving sync.

• Cause– System fault in the MRT Satellite terminal, check HPA,

LNB, and cables via wiring diagrams.

• Symptom– One terminal will not enter the network.

• Cause– Satellite terminal problem on the distant end, assist in

trouble shooting as applicable.– Ensure terminal is peaked on the satellite.– Boot File is incorrect. Ensure terminal is configured

correctly, especially latitude and longitude.

Questions?

TAB

Insert Tab # 8 Here

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Adding Control Groups

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Why an Additional Control Group?

• If a network becomes too busy or has too many terminals, one RB is not sufficient to update the TT’s in a timely manner.

• Symptoms of this are dropped PVC’s, PVC tables having to be reloaded, and timeouts in the conolog files in the ETC directory.

Since network timing is controlled via receive bursts from the MRT, if there are too many terminals on the network or too much data is being passed, the traffic bursts will become too numerous for one traffic burst to control. If sufficient control over timing within the network is not maintained, the number of traffic collisions will increase, resulting in lost data that will then have to be retransmitted. This lag in the network will cause PVCs to be dropped, necessitating their re-entry in PVCs tables. Therefore, it is essential that additional receive bursts are introduced to the network to better control timing and increase network efficiency. Additional control groups provide these additional receive bursts.

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When to add a Control Group

• Only Add A Control Group When Instructed To By Network Operations Or When It Is Part Of The Initial Configuration.

Since improperly added control groups can actually increase network latency, as well as errors, it is important to add an additional control group only when necessary as determined by network engineers.

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Adding Control Groups Procedure (1)

• On the active NCC copy the carrieradmin.tdb file from db to dbnew.

• Open the file in file manager.

• Copy and paste the four lines of text, four times with a blank line between each group.

The information contained in the carrieradmin.tdb file determines what traffic goes over what carrier. Since the db directory provides an initial back-up and configuration function, copying and then altering the file in the dbnew directory will actually provide the information from which the NCC controls the carriers.

120


• Edit the groups so that the first group is SrcCGroup: 0; DstCGroup: 0; Second Group is SrcCGroup: 0; DstCGroup: 1; Third Group is SrcCGroup: 1; DstCGroup: 0; Fourth Group is SrcCGroup: 1; DstCGroup: 1.

• Copy and paste the four groups, change carrier ID to 1 in the second set of four.

• Repeat for all carriers.• Save and close the file.

This control group information delineates which control groups can transmit and receive on which carrier. For example, in the default settings, Control Group 0 can send information to itself (since SrcCGroup 0 has a DstCGroup value of 0), as well as to Control Group 1 (DstCGroup 1). Control Group 1 is configured in the same manner. Changing the Carrier ID to 1 means that those Control Groups originating from that carrier will only burst over that carrier.

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• Copy cgroup.tdb from db to dbnew.

• Open the file.• Copy and past the first

two lines of the file, leaving a space between the entries.

• Change the second entry to CGroupId : 1

• Save and close the file.


Editing the cgroup.tdb file and moving the edited to file to dbnew simply tells the NCC that there is now more than one Control Group to be used.

122

• The Sigburstdef.tdb file must now be edited.– Open a file manager window and navigate to

/home/linkway/etc.datapath/etc/dbnew and find the Sigburstdef.tdb file.

– If the file does not exist go to the /home/linkway/etc.datapath/etc/db directory and copy the Sigburstdef.tdb file to the dbnew directory.

– If the file does exist copy the file to the current directory and rename it as Sigburstdef.old.


Renaming the sigburstdef.tdb file as sigburstdef.old helps to identify which sigburstdef file is the original and which is the edited version.

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• In the file manage window, double click on the Sigburstdef.tdb file. To the left is an example of the file.


• Ensure there is a space after the last entry in the file.

• Copy all the text in the file and paste it below the existing file text.


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• At this point the file should display two groups of four burst ID’s each labeled 1 – 4.

Burst ID’s


• Change the second group of four burst ID’s to 5 – 8.

Burst ID’s


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• In Burst ID 5 change the following lines:– Carrier ID to 1.– Dst to 0x1ffff– DataSink to 0x1ffff


Once the CarrierId is altered to 1 from 0, the edited bursts identified in the sigburstdef.tdb file will ONLY appear on Carrier 1.

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• In Burst ID’s 6 through 8 change the following lines:– Carrier ID to 1.– Src to 0x1ffff– DataSrc to 0x1ffff– Additional control groups replace the 1 with 2 etc. until all control groups are

configured.


• Review the file to ensure it is correct.

• Save and close the Sigburstdef.tdb file.


127

• Open the routab.tdb file in a window.

• Copy the first five lines and paste it into four groups.

• Edit groups 2 through 4 as shown.

• Repeat as necessary for each additional control group.


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• Review the file to ensure it is correct.

• Save and close the routab.tdb file.

• Stop and restart the NCC processes

• Start the NMS on the NMS laptop.

• Open the Burst Time Plan window and verify the additional control group is present.

• Any existing Site that will be assigned to a new control group, must be deleted, reconfigured, and added to the correct control group.


When viewing the Burst Time Plan, ensure that the two control groups appear on two separate carriers. Once again, if there is more than one control group on a single carrier, signaling collisions will occur. If, for some reason, the Burst Time Plan cannot be viewed graphically, enter the command rbtpon the MRT. More than one control group on one carrier will result in the number of Viterbi Corrections on the MRT rising quickly.

129

Adding Control Groups Validation

• Burst Time Plan should display a control group on each carrier that one has been assigned.

Questions?

130

Notes Page

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